Dissertations / Theses on the topic 'Controllo chimico'

Metodiche sperimentali per l'abbattimento del fosforo, mediante precipitazione chimica, con l'utilizzo di una miscela di PAC/Poliammina e degradazione dei tensioattivi, con l'impiego di un bioreattore, utilizzando ceppi batterici selezionati. L'applicazione in campo è stata effettuata sugli impianti di Sammichele di Bari, Noci e Castellana Grotte ricadenti nella provincia di Bari e gestiti dalla società Acquedotto Pugliese S.p.A.

La chimie quantique est un domaine de recherche de plus en plus present dans les preoccupations des mathematiciens appliques. S'inscrivant dans cet mouvement, cette these propose quelques etudes d'analyse de methodes numeriques de simulation et controle en chimie quantique. La partie i est dediee a la presentation du cadre general de la chimie quantique computationnelle. Les techniques d'estimation a posteriori et leurs applications a la chimie quantique sont presentees dans la partie ii. Apres une introduction aux methodes a posteriori (chapitre ii-1) on presente dans le chapitre ii-2 une etude mathematique de la methode des variables adiabatiques et on propose en particulier un estimateur a posteriori. Des simulations numeriques qui illustrent les qualites de cet estimateur sont aussi presentees. Une etude d'analyse a posteriori de l'equation de hartree-fock est presentee en chapitre ii-3. Outre la construction d'un intervalle de confiance pour localiser l'energie de hartree-fock, la meme methode fournit un procede d'amelioration des solutions numeriques. Ces resultats theoriques ont ete testes et implementes sur un code de chimie quantique. Une etude concernant le controle au niveau quantique des phenomenes chimiques est presentee dans la partie iii. Des resultats permettant de decider de la controlabilite d'un systeme de dimension finie sont presentes en iii-1-2. Les criteres sont simples a verifier et donnent lieu a des interpretations intuitives. Des resultats theoriques complementaires et des exemples numeriques sont proposes dans iii-1. 3. Finalement, un code qui implemente des algorithmes genetiques pour l'etude des mecanismes de controle est decrit en chapitre iii-2.

Il presente lavoro di tesi, nell’ambito del Research and Development R&D, è frutto del tirocinio effettuato presso l’azienda Coind s.c. sita a Castel Maggiore in provincia di Bologna. L’attività svolta è stata ripartita su due tematiche differenti: lo studio della normativa di riferimento in materia di controllo della massa e dei prodotti pre-imballati e, successivamente, lo studio di nuovi materiali eco-sostenibili utilizzabili nell'industria alimentare. Il primo obiettivo è la stesura di una procedura operativa per il controllo automatico della massa in linea attraverso l’impiego di selezionatrici ponderali al fine di misurare la quantità effettiva di prodotto tramite il calcolo della tara e la stima dell’incertezza correlata. La necessità di avere una procedura è data dal fatto che gli imballaggi pre-confezionati devono indicare sull’etichetta una serie di informazioni all’attenzione dei consumatori, tenendo conto degli errori di misurazione consentiti dalla legge. Il secondo obiettivo consiste nell’analisi dell’etichettatura ambientale sui materiali esistenti e nello sviluppo di imballaggi a basso impatto ambientale siano essi riciclabili che in materiale biodegradabile e/o compostabile (UNI EN 13432:2002) da impiegare nel confezionamento del caffè al fine di individuare il più competitivo sul mercato. Per raggiungere questo scopo sono state svolte prove di pre-industrializzazione con materiali innovativi e riciclabili, test di permeabilità ai gas per valutare la possibilità di eliminare lo strato di alluminio che caratterizza gli imballaggi attualmente in uso e test organolettici come il Test della Beuta per valutare l’eventuale difetto organolettico di un materiale da imballaggio o il Test Triangolare al fine di individuare eventuali differenze sensoriali tra due prodotti lungo la loro shelf life. Lo sviluppo dei nuovi materiali è nato a seguito di aggiornamenti normativi che chiedono la riduzione dell’impatto ambientale del fine vita del prodotto.

Heavy liquid metals (HLMs) such as lead and lead-bismuth eutectic are considered as primary coolants in Lead-cooled Fast Reactor and Accelerator Driven System. A major issue in HLM-cooled nuclear reactors concerns the HLM chemistry and the dissolved oxygen, which has to be balanced within an optimal concentration range to prevent HLM oxidation and minimize corrosion of steels in contact with the HLM via formation of a protective Fe-Cr oxide layer. In this framework, the present research focused on the development of oxygen sensors based on solid-electrolyte and the control of the oxygen concentration in HLM via gas phase. A baseline study about the performance of different sensors was carried out in laboratory scale. Solid electrolytes such as Yttria Partially and Totally Stabilized Zirconia were considered as well as internal references such as the Pt-air, Bi/Bi2O3 and Cu/Cu2O. The sensors were calibrated in HLM in a wide temperature range to assess the minimum reading temperature and the accuracy. In parallel, the development and the test of a sensor for large HLM pools was performed. The sensors so manufactured were used to study the HLM deoxygenation with Ar-H2 gas in different conditions of H2 concentration, HLM temperature and HLM fluid-dynamic regime. A gas control system was implemented to create safe gas mixtures with flexible H2 concentration and to obtain easy HLM deoxygenation in small steel capsules and HLM storage tanks. The HLM deoxygenation in dynamic condition was performed with success in a loop facility by injecting Ar-3%H2 and the effect of metal-oxygen interactions in the HLM was analysed. The results here obtained helped in identifying the factors influencing the process and led to a preliminary and qualitative interpretation of the deoxygenation mechanism.

Mimicking the allosteric control typical of enzymatic catalysis is a long lasting goal for chemists. The present thesis deals with the development of new strategies to control the performance and hopefully switch ON and OFF homogeneous catalysts by implementing photochemical and supramolecular devices. As long as the photochemical approach is concerned, a new phosphine ligand endowed with a coumarin moiety, known to be a typical photo-dimerizable molecule, was prepared and employed for the preparation of Pt(II) metal complexes. The ligand topicity on the complex could be switched from monodentate to bidentate upon irradiation and coumarin dimerization. This feature was investigated in different solvents and exploited in three different catalytic reactions such as alkene isomerization and dimerization as well as Diels-Alder cycloaddition. In all cases the photodimerized catalyst bearing the bidentate ligand showed clearly a different behaviour with respect to the original catalyst bearing two monophosphines. Another approach consisted in the synthesis and study of the coordination properties of new phosphine ligands incorporating a dithienyl moiety which is known to be an excellent reversible photochromic unit characterized by geometric and electronic variations between two isomeric forms. The electronic properties of the ligands were studied in detail by synthesis of the corresponding selenides and Rh(I)carbonyl Vaska type complexes. Dithienyl derivatives bearing pyridine moieties were also prepared to be transformed by alkylation into the corresponding biscations and these were employed as competitive inhibitors for supramolecular catalysts. In particular, they were tested both in organic medium in the reaction of hydration of isonitriles catalyzed by a self-assembled hexameric capsule based on resorcin[4]arene units and in aqueous medium in the Diels Alder cycloaddition reaction between standard dienes and dienophiles catalyzed by b-cyclodextrin. In former case the two photogenerated isomeric dithienyl cations led to different inhibition activity as a consequence of their different geometry that results in modified host-guest interactions with the supramolecular catalysts employed. The above mentioned hexamer has been successfully exploited as an allosteric reversible supramolecular effector able to modulate the photo-catalytic activity of [Ru(bpy)3](OTf)2 in the sulfoxidation of thioethers in organic medium in the presence of molecular oxygen. The catalytic activity was reversibly turned off when the Ru(II) catalyst was hosted within the hexameric capsule, and was turned on by addition of a competitive guest for the hexamer such as tetraethylammonium triflate. This approach emonstrates that simply changing the solvation sphere of a catalyst form the bulk solvent into a more static supramolecular assembly it is possible to completely control the performance of a catalyst. Overall, the present PhD dissertation introduced innovative photochemical and supramolecular approaches to modulate the homogeneous catalytic activity of a catalyst opening the road to further developments and possible applications.
La mimesi delle proprietà allosteriche proprie degli enzimi è da sempre una delle sfide più stimolanti per i chimici. In questo lavoro di tesi sono state prese in considerazione diverse strategie per modulare le prestazioni di catalizzatori omogenei, dagli approcci supramolecolari all’incorporazione di residui fotochimici all’interno del sistema catalitico stesso. In un primo approccio il residuo cumarinico, noto per le reazioni di fotocicloaddizione, è stato incorporato all’interno di un legante fosfinico che è stato a sua volta impiegato nella sintesi di bisfosfino complessi di Pt(II). La dimerizzazione del residuo cumarinico ha permesso il passaggio del sistema legante da monodentato a bidentato e i conseguenti complessi fotoreagito e non, sono stati testati nelle reazioni di isomerizzazione e dimerizzazione di alcheni e nelle reazioni di Diels Alder. In tutti i casi sono state osservate apprezzabili variazioni di attività tra le due forme, in particolar modo nelle reazioni di Diels Alder. Un secondo studio ha previsto l’incorporazione del residuo ditieniletene all’interno di leganti di tipo fosfinico, allo scopo di verificare come il passaggio dalla forma aperta a quella ciclizzata del diariletene influenzi le proprietà elettroniche del legante stesso. Lo studio delle proprietà è stato realizzato tramite la sintesi dei corrispondenti complessi di Rh(I) di tipo Vaska e dei seleniuri delle fosfine; in particolare questi ultimi hanno permesso di valutare le differenti capacità σ-donatrici per gli isomeri aperti e chiusi. Il residuo diariletene è stato quindi studiato nell’ottica di inibitore fotomodulabile nei confronti di specie catalitiche supramolecolari. In un primo approccio in mezzo organico è stato osservato che le due forme isomeriche di un piridinio, incorporante il residuo ditieniletene, mostrano diversa abilità nella reazione di idratazione di isonitrili mediate dal complesso esamerico ottenuto a partire dal resorcin[4]arene. Entrambe le forme dell’inibitore foto modulabile sono state successivamente studiate in soluzione acquosa in presenza di β-ciclodestrina e le interazioni host-guest tra i due componenti sviscerate. Dagli studi effettuati si è dedotto che, anche in questo le due forme fotocromiche del piridinio possano determinare un diverso effetto inibitore in reazioni test quali cicloaddizioni catalizzate da β-ciclodestrina. L’esamero sopracitato è stato infine impiegato quale effettore supramolecolare nei confronti del complesso [Ru(bpy)3]2+, nella foto-ossidazione aerobica di tioeteri. L’esamero ha dimostrato totale capacità di inibizione della reazione in virtù della sua capacità di incapsulare il catalizzatore inoltre, il completo controllo allosterico è stato ottenuto ripristinando l’attività catalitica tramita aggiunta di un competitor per la capsula esamerica. In conclusione il presente lavoro di tesi ha affrontato diversi aspetti del controllo allosterico proponendo nuove strategie per il controllo di sistemi catalitici omogenei e aprendo la strada per futuri sviluppi e applicazioni.

Lignin represents a highly valuable, yet very underutilized biobased material. Being the most abundant source of aromatics on the planet, it is produced in high quantities as by-product of pulp and paper industries and biorefineries. Due to the high degree of structural variability, which depends on the different plant origin and harsh conditions experienced during the processing, an exhaustive valorisation of lignin is all but straightforward. Among various possibilities, the synthesis of micro- and nano-structures from untreated technical lignins is one of the best solutions for the development of high added-value products exploiting the peculiar features of lignin, such as self-assembly capacity, antimicrobial and antioxidant activities. To this purpose, this Thesis work has been focused on the preparation of lignin microcapsules (LMCs) by a simple, green and easily scalable ultrasound-assisted method. By this strategy it is possible to encapsulate lipophilic substances like pesticides, food additives, flavours or water insoluble drugs in a shell of lignin, from which they can be released upon changing the environmental factors such as pH, salinity etc. To modulate the characteristics of the capsules, either ad hoc prepared green compatibilizers or an outer biopolymeric layer have been added to the formulation. The synthesized LMCs have been characterized from the dimensional and morphological point of view by dynamic light scattering and microscopy techniques. Furthermore, the encapsulation efficiency, their stability under different conditions and the kinetic of release of a model compound have been studied to demonstrate their potential as carriers of active molecules.

Nanotechnology entails the manufacturing and manipulation of matter at length scales ranging from single atoms to micron-sized objects. The ability to address properties on the biologically-relevant nanometer scale has made nanotechnology attractive for Nanomedicine. This is perceived as a great opportunity in healthcare especially in diagnostics, therapeutics and more in general to develop personalized medicine. Nanomedicine has the potential to enable early detection and prevention, and to improve diagnosis, mass screening, treatment and follow-up of many diseases. From the biological standpoint, nanomaterials match the typical size of naturally occurring functional units or components of living organisms and, for this reason, enable more effective interaction with biological systems. Nanomaterials have the potential to influence the functionality and cell fate in the regeneration of organs and tissues. To this aim, nanotechnology provides an arsenal of techniques for intervening, fabricate, and modulate the environment where cells live and function. Unconventional micro- and nano-fabrication techniques allow patterning biomolecules and biocompatible materials down to the level of a few nanometer feature size. Patterning is not simply a deterministic placement of a material; in a more extended acception it allows a controlled fabrication of structures and gradients of different nature. Gradients are emerging as one of the key factors guiding cell adhesion, proliferation, migration and even differentiation in the case of stem cells. The main goal of this thesis has been to devise a nanotechnology-based strategy and tools to spatially and temporally control biologically-relevant phenomena in-vitro which are important in some fields of medical research.

Nanotechnology entails the manufacturing and manipulation of matter at length scales ranging from single atoms to micron-sized objects. The ability to address properties on the biologically-relevant nanometer scale has made nanotechnology attractive for Nanomedicine. This is perceived as a great opportunity in healthcare especially in diagnostics, therapeutics and more in general to develop personalized medicine. Nanomedicine has the potential to enable early detection and prevention, and to improve diagnosis, mass screening, treatment and follow-up of many diseases. From the biological standpoint, nanomaterials match the typical size of naturally occurring functional units or components of living organisms and, for this reason, enable more effective interaction with biological systems. Nanomaterials have the potential to influence the functionality and cell fate in the regeneration of organs and tissues. To this aim, nanotechnology provides an arsenal of techniques for intervening, fabricate, and modulate the environment where cells live and function. Unconventional micro- and nano-fabrication techniques allow patterning biomolecules and biocompatible materials down to the level of a few nanometer feature size. Patterning is not simply a deterministic placement of a material; in a more extended acception it allows a controlled fabrication of structures and gradients of different nature. Gradients are emerging as one of the key factors guiding cell adhesion, proliferation, migration and even differentiation in the case of stem cells. The main goal of this thesis has been to devise a nanotechnology-based strategy and tools to spatially and temporally control biologically-relevant phenomena in-vitro which are important in some fields of medical research.

Questo lavoro di tesi è stato indirizzato alla valorizzazione di biomassa acquatica reperita in ambito locale (Veneto), per il suo successivo utilizzo in ambito cosmetico. La prima parte del lavoro è stata focalizzata sull’ottimizzazione di un approccio sintetico green ed efficiente per la trasformazione della biomassa in molecole attive (polisaccaridi-polifenoli-proteine-acidi grassi). Gli estratti ottenuti sono stati poi utilizzati per la preparazione di formulati cosmetici anti-age mediante il processo sol-gel. I prodotti ottenuti sono stati analizzati mediante una serie di test standardizzati finalizzati a valutarne stabilità, proprietà sensoriali ed efficacia. L’efficacia è stata valutata in vitro mediante cella a diffusione verticale di Franz utilizzando membrane ex-vivo preparate a partire da orecchie di maiale. Il test di tape-stripping è stato utilizzato per valutare la capacità del formulato di favorire la penetrazione degli attivi, mentre il potere antiossidante del formulato è stato investigato mediante il test del DPPH (difenilpicrilidrazile).

Lignin is the most abundant aromatic biopolymer on Earth. Every year, about 70x10(^6) tons of lignin are produced, but its utilization for the production of high added-value materials is not so easy and direct. This is due to the highly complex structure of this material, which also differs depending on the botanical origin. Moreover, the harsh conditions of the industrial extraction processes (from which the so-called “technical lignins” are obtained) contribute to significantly modify its structure making it very dissimilar to the native one. Nonetheless, in the last years several attempts towards lignin valorisation have been made, and uses of this renewable biopolymer in place of less eco-friendly and synthetic materials have increased. In particular, the direct generation of nanostructures from technical lignins is highly attractive because it allows for the exploitation of their peculiar characteristics without the need for time-consuming and costly pre-treatments. In this context, the present Thesis work aims at developing lignin microcapsules for the controlled delivery of lipophilic actives, using ultrasonication as a green and scalable method of synthesis. Time-dependent release of the active and capsule stability at different pH conditions were evaluated, taking into account different lignin/active ratios and the effect of ad hoc prepared additives. Morphological and structural characterisations were carried out as well to extrapolate structure-property relationships.

Multicomponent reactions (MCRs) are processes that show high atom and step economy; two different parts of my thesis were linked by MCRs. In the first part, levulinic acid was converted into a variety of bicyclic nitrogen heterocycles passing by an Ugi reaction. The obtained intermediate was then converted in the final product via a simple SN2 cyclization. The second part, instead, was dedicated to the obtainment of organo-catalysts structurally based on secondary and tertiary amine groups. First attempts, to get the latter in bicyclic structures, involved a starting MCR with L-prolinol, but the reaction showed low diastereoselectivity and the cyclization failed. A different strategy was aimed to obtain secondary amines and resulted to be more efficient. The involvement of a seven-membered cyclic imine, with a chiral center in C-3, in a Ugi-Joullié reaction resulted in a very diastereoselective process. Using a silyl oxy derived carboxylic acid, an Ugi adduct with a protected alcohol is obtained. Thus, an intramolecular cyclization can be performed producing the final free amine group. The obtained amine was used to perform the first catalysis tests in Michael and aldol reactions. Although no catalytic activity was detected, different reaction conditions and structures have still to been tested. Finally, the reaction mechanism in self-promoted glycosylations was investigated. They involve a trichloroacetimidate as glycosyl donor which is activated by an acceptor that contains an acid sulfonamide portion. An alcoholic function was added to the acceptor with a consecutive possible production of both O- and N-glycosides. Dissociative mechanism favors the first while an associative mechanism brings to the second. The study showed the chemoselectivity and, to some extent, the stereoselectivity of the reaction to be controlled by tuning the parameters e.g. the polarity of the solvent, the concentration of donor and acceptor and the use of additives such as lithium salts.

Nelle strutture supramolecolari, le interazioni host-guest sono uno dei principali fenomeni di riconoscimento che spesso coinvolgono macrocicli organici (host) in combinazione con una vasta gamma di molecole ospite (guest), in cui l'associazione tra le specie è tipicamente guidata da interazioni deboli di tipo attrattivo o dall’effetto idrofobico. Uno dei complessi host-guest più studiati ed utilizzati in applicazioni industriali, commerciali e farmaceutiche è il sistema Azobenzene/Ciclodestrine (Azo/CDs). La funzionalità azobenzenica può essere isomerizzata selettivamente dalla configurazione trans a quella cis mediante radiazioni luminose nell’intervallo dell’UV, e viceversa da cis a trans attraverso luce visibile o calore. L'isomerizzazione inoltre, determina il cambiamento delle proprietà molecolari quali la geometria e la polarità. Utilizzando le proprietà delle molecole azobenzeniche alle diverse lunghezze d'onda per la creazione di intermedi supramolecolari host-guest in sistemi dinamici per la sintesi enzimatica di ciclodestrine, è possibile manipolare e controllare tali reazioni al fine di ottenere prodotti specifici quali α- CD, β-CD o γ-CD. Lo scopo di questo lavoro di tesi è quello di sviluppare nuove molecole azobenzeniche aventi differenti proprietà steriche e di solubilità in ambiente acquoso attraverso la modifica dei sostituenti presenti nel sistema aromatico dell’azocomposto. Utilizzando una reazione enzimatica per generare una miscela dinamica di α-1,4-glucani lineari e ciclici ed impiegando l’azobenzene come templante, è possibile ottenere e studiare le derivanti librerie combinatoriali enzima-mediate (DCL) per definire l’effetto degli azo-templanti nella sintesi ciclodestrinica, a seguito delle diverse condizioni di irraggiamento. A causa dell'emergenza Covid-19, il presente lavoro è stato interrotto nella fase sintetica delle molecole azobenzeniche e non è stato possibile completare gli obiettivi precedentemente riportati. Per completare la tesi è stato quindi condotto uno studio approfondito su sistemi host-guest foto-modulabili costituiti da ciclodestrine ed azobenzene, analizzando i meccanismi di isomerizzazione delle varie specie e le loro applicazioni recenti e future in numerosi campi scientifici quali la medicina, la farmaceutica, l’ingegneria, la sensoristica e la catalisi.

The temporospatial controlled delivery of growth factors is crucial to trigger the desired healing mechanisms in target tissues. The uncontrolled release of growth factors has been demonstrated to cause severe side effects in its surrounding tissues. Thus, the first working hypothesis was to tune and optimize a newly developed multiscale delivery platform based on a nanostructured silicon particle core (pSi) and a poly (dl-lactide-co-glycolide) acid (PLGA) outer shell. In a murine subcutaneous model, the platform was demonstrated to be fully tunable for the temporal and spatial control release of the payload. Secondly, a multiscale approach was followed in a multicompartment collagen scaffold, to selectively integrate different sets of PLGA-pSi loaded with different reporter proteins. The spatial confinement of the microspheres allowed the release of the reporter proteins in each of the layers of the scaffold. Finally, the staged and zero-order release kinetics enabled the temporal biochemical patterning of the scaffold. The last step of this PhD project was to test if by fully embedding PLGA microspheres in a highly structured and fibrous collagen-based scaffold (camouflaging), it was possible to prevent their early detection and clearance by macrophages. It was further studied whether such a camouflaging strategy was efficient in reducing the production of key inflammatory molecules, while preserving the release kinetics of the payload of the PLGA microspheres. Results demonstrated that the camouflaging allowed for a 10-fold decrease in the number of PLGA microspheres internalized by macrophages, suggesting that the 3D scaffold operated by cloaking the PLGA microspheres. When the production of key inflammatory cytokines induced by the scaffold was assessed, macrophages' response to the PLGA microspheres-integrated scaffolds resulted in a response similar to that observed in the control (not functionalized scaffold) and the release kinetic of a reporter protein was preserved.

The temporospatial controlled delivery of growth factors is crucial to trigger the desired healing mechanisms in target tissues. The uncontrolled release of growth factors has been demonstrated to cause severe side effects in its surrounding tissues. Thus, the first working hypothesis was to tune and optimize a newly developed multiscale delivery platform based on a nanostructured silicon particle core (pSi) and a poly (dl-lactide-co-glycolide) acid (PLGA) outer shell. In a murine subcutaneous model, the platform was demonstrated to be fully tunable for the temporal and spatial control release of the payload. Secondly, a multiscale approach was followed in a multicompartment collagen scaffold, to selectively integrate different sets of PLGA-pSi loaded with different reporter proteins. The spatial confinement of the microspheres allowed the release of the reporter proteins in each of the layers of the scaffold. Finally, the staged and zero-order release kinetics enabled the temporal biochemical patterning of the scaffold. The last step of this PhD project was to test if by fully embedding PLGA microspheres in a highly structured and fibrous collagen-based scaffold (camouflaging), it was possible to prevent their early detection and clearance by macrophages. It was further studied whether such a camouflaging strategy was efficient in reducing the production of key inflammatory molecules, while preserving the release kinetics of the payload of the PLGA microspheres. Results demonstrated that the camouflaging allowed for a 10-fold decrease in the number of PLGA microspheres internalized by macrophages, suggesting that the 3D scaffold operated by cloaking the PLGA microspheres. When the production of key inflammatory cytokines induced by the scaffold was assessed, macrophages' response to the PLGA microspheres-integrated scaffolds resulted in a response similar to that observed in the control (not functionalized scaffold) and the release kinetic of a reporter protein was preserved.

Desymmetrization reactions has emerged as a cutting-edge approach in recent years for the synthesis of enantioenriched compounds. The demand of enantiopure organic compounds in the pharmaceutical and fine chemical industry increased in the recent years giving the impetus to the development of new chiral technologies. Among them, the catalytic asymmetric synthesis represents the economically-optimal route to obtain chiral building blocks. During the course of my PhD we investigated the use of organic catalysts to promote the formation of enantioenriched products from achiral or meso- starting materials.

This Thesis deals with the problem of the quality control and monitoring and the related energy consuming aspects in industrial multicomponent distillation columns. These have important relevance especially in case of units subjected to important changes in operating conditions which manifests in fluctuation of the product concentration. Due to the low reliability of the seldom available and delayed analytic composition measurements, they cannot be employed for an efficient online monitoring of the separation. Instead, this Thesis proposes the use of composition observers with passive innovation mechanism and driven by temperature measurements. The passive structure allows to limit the number of ODEs to be online integrated, which is a central issue to obtain a product suitable for the industrial implementation. The design of this passive structure involves the choice of number and location of the temperature sensors, the choice of the innovated component and the set of modeled components in the (possibly simplified) estimation model. This issue is addressed with a simple and systematic methodology that employs steady state information about the per-component temperature gradient of the column and detectability measures and conditions. Differently from the majority of the works in literature, the proposed methodology allows also to assess the feasibility of obtaining good estimation performance using the available temperature sensors in real columns. Even the analytic composition measurements cannot be employed for quality control in feedback control loops mainly due to delay problems. Instead, temperature feedback controllers are usually used. But even if the temperature sensor is well located (and in this Thesis a criterion for sensor location is suggested based on an extension of the slope criterion to the multicomponent case), when the operating conditions undergo changes, the indirect regulation of the product quality cannot be achieved, with alternating periods of under and over-purification that also adversely affect the energy requirement for the column functioning. Thus, in this Thesis an application oriented solution is proposed consisting in adding a feedforward temperature setpoint compensation that guarantee a close quality regulation, including a more efficient management of the energy, under the changing operating modes of the column. The methodologies and techniques proposed and described in this Thesis are tested with an industrial multicomponent IC4-NC4 splitter located at the Sarlux Refinery (Sarroch, Italy), which, motivated by the good results, has already implemented the composition estimator and is going to implement the feedforward setpoint compensator.

Les emulsions offrent un milieu de synthese aux multiples qualites qui permettent un meilleur controle de la reaction chimique et un degre de liberte plus eleve pour intervenir sur les proprietes morphologiques telles que la taille et la forme. Grace a l'utilisation des micelles directes (gouttelettes d'huile dans l'eau), nous avons reussi a preparer une serie d'echantillons de particules magnetiques de ferrite de cobalt cofe#2o#4 de taille calibree allant de 2 a 5 nm avec une polydispersite de 30%. La taille des particules a ete determinee par microscopie electronique a transmission, diffusion des rayons x aux petits angles et enfin par diffraction des rayons x. Les mesures d'aimantation, et l'etude par spectroscopie mossbauer en fonction de la temperature, ont montre un comportement superparamagnetique de ces nanoparticules, la constante d'anisotropie mesure par ces deux techniques augmente quand la taille diminue

Il controllo degli artropodi infestanti le derrate in post-raccolta si basa principalmente sull’utilizzo di molecole chimiche di sintesi. I loro residui – spesso presenti nei prodotti alimentari finiti – hanno destato nell’opinione pubblica crescenti preoccupazioni di ordine igienico sanitario. Anche la legislazione Europea – dal canto suo – impone limiti restrittivi alla loro presenza nei cibi e al loro uso. Nell’ambito delle tecniche alternative ai pesticidi di sintesi, gli oli essenziali mostrano interessanti potenzialità per il controllo degli insetti. Il lavoro svolto in questa tesi si è proposto di valutare l’efficacia insetticida di due oli essenziali commerciali, estratti da Cannabis sativa L. e Coridothymus capitatus (L.) Rchb. f., nel controllo di Tribolium castaneum Herbst, uno degli insetti più dannosi delle derrate. La loro caratterizzazione chimica ha permesso di individuare alcune molecole che presumibilmente sono responsabili dell’azione tossica nei confronti del coleottero. I risultati ottenuti mostrano un’attività insetticida di entrambi gli oli essenziali in condizione di temperatura modificata. All’interno di un moderno protocollo di lotta integrata agli insetti, gli oli essenziali potranno effettivamente rappresentare uno tra i diversi ausili tecnici alternativi agli insetticidi di sintesi, che puntino a ridurre al minimo la presenza di residui chimici nei prodotti alimentari.

Le controle des conditions de precipitation en milieu aqueux (ph, force ionique) de la magnetite permet de maitriser la taille de particules nanometriques et d'eviter les phenomenes de vieillissement. On montre que la taille moyenne des particules s'abaisse a mesure que le ph et la force ionique s'elevent. Cette variation est correlee a l'augmentation de la densite de charge electrostatique de surface des particules. Dans les conditions ou la charge de surface est maximale et l'interface electrostatiquement saturee, les equilibres de dissolution-cristallisation impliques dans le veillissement n'interviennent plus. La taille des particules est alors directement reliee au ph de la solution. L'interpretation et la modelisation, fondees sur l'equation d'adsorption de gibbs consistent a evaluer l'abaissement de tension interfaciale oxyde-solution avec l'adsorption des ions hydroxyles. En supposant la tension interfaciale nulle ou proche de zero a l'equilibre, le traitement quantitatif du phenomene permet de definir les conditions de stabilite du systeme dans le temps et de rendre compte avec precision de la taille des particules. Le modele semble aussi permettre d'interpreter la stabilisation de certaines phases metastables en suspension, telles la boehmite et l'akaganeite dont la transformation en bayerite et en hematite respectivement peut etre considerablement ralentie voire evitee a haute force ionique

Il plasma, quarto stato della materia, rappresenta un gas ionizzato in cui ioni ed elettroni si muovono a diverse energie sotto l’azione di un campo elettro-magnetico applicato dall’esterno. I plasmi si dividono in plasmi di equilibrio e di non equilibrio termodinamico, quest’ultimi sono caratterizzati da un’alta temperatura elettronica (oltre 10000 K) e da una bassa temperatura traslazionale degli ioni e delle specie neutre (300-1000 K). I plasmi di non equilibrio trovano largo impiego nella microelettronica, nei processi di polimerizzazione, nell’industria biomedicale e del packaging, consentendo di effettuare trattamenti di sterilizzazione e attivazione superficiale. Il lavoro di tesi è incentrato sui processi di funzionalizzazione e polimerizzazione superficiale con l’obbiettivo di realizzare e caratterizzare sorgenti di plasma di non equilibrio a pressione atmosferica operanti in ambiente controllato. È stata realizzata una sorgente plasma operante a pressione atmosferica e in ambiente controllato per realizzare trattamenti di modifica superficiale e di polimerizzazione su substrati polimerici. L’efficacia e l’omogeneità dei trattamenti eseguiti sono stati valutati tramite misura dell’angolo di contatto. La caratterizzazione elettrica ha consentito di determinare i valori di densità di energia superficiale trasferita sui substrati al variare delle condizioni operative. Lo strato depositato durante il processo di polimerizzazione è stato analizzato qualitativamente tramite l’analisi chimica in spettroscopia infrarossa. L’analisi delle prove di funzionalizzazione dimostra l’uniformità dei processi plasma eseguiti; inoltre i valori dell’angolo di contatto misurati in seguito ai trattamenti risultano confrontabili con la letteratura esistente. Lo studio dei substrati trattati in atmosfera satura d’azoto ha rivelato una concentrazione superficiale di azoto pari al 3% attribuibile alla presenza di ammine, ammine protonate e gruppi ammidici; ciò conferma la bontà della soluzione realizzata e dei protocolli operativi adottati per la funzionalizzazione delle superfici. L’analisi spettroscopica dei trattamenti di polimerizzazione, ha fornito spettri IR confrontabili con la letteratura esistente indicando una buona qualità del polimero depositato (PEG). I valori misurati durante la caratterizzazione elettrica della sorgente realizzata risulteranno fondamentali in futuro per l’ottimizzazione del dispositivo. I dati raccolti infatti, determineranno le linee guida per il tailoring dei trattamenti plasma e per lo sviluppo della sorgente. Il presente lavoro di tesi, pur prendendo in esame una piccola parte delle applicazioni industriali dei plasmi non termici, conferma quanto queste siano pervasive nei comuni processi industriali evidenziandone le potenzialità e i numerosi campi d’applicazione. La tecnologia plasma è destinata ad essere imprescindibile per la ricerca di soluzioni innovative ai limiti dei processi tradizionali.

The market of food supplements is expanding quickly; these products, especially those derived from plants, are usually considered as "natural" and free of side effects. They are often used by patients at their own discretion, in a uncontrolled way and without medical advice. Furthermore, some of these supplements have never been included in clinical studies that prove their efficacy and / or safety and for some of these products do not exist a correspondence between the contents indicated on the label and the real one. This means that consumers could buy them, or also import them, if not available in the market of their country, without any difficulty but even without receiving any guarantee about their quality. In addition to the risk that these products may present for consumer’s health, there is a risk for professional athletes to obtain positive results in drug tests. The competent authorities and food businesses need for scientific information on the quality and safety of these products, including those imported from abroad. The purpose of the first part of this study was to conduct a systematic review on adverse effects of dietary supplements containing the plant Citrus aurantium, alone or in combination with other stimulant compounds. Data on adverse events in humans following the consumption of these products have been collected in the literature and a causality assessment of clinical cases, when not specified, was performed in agreement with the Pharmacovigilance Guidelline from the World Health Organization. The purpose of the second part of this thesis was to verify the contents of active amines and steroidal compounds in food supplements, paying particular attention to products based on plant extracts. Various analytical approaches have been used for the detection and quantification of these compounds: Thin Layer Chromatography (TLC), High Performance Liquid Chromatography (HPLC) and Liquid Chromatography Mass Spectrometry (LC-MS). This investigation has at the same time allowed us to verify the accuracy of the information given on the products label by comparing them with the actual content of the substances measured. This research is part of the activities in the European Project PlantLIBRA (Plant Food Supplements: Levels of Intake, Benefit and Risk Assessment). The project is part of the Seventh European Framework Programme, which aims to evaluate the efficacy and safety of food supplements containing plants and derivatives, in order to support regulatory actions.

For pharmaceutical companies, the economic return on investments on research and development has recently been decreasing, mainly due to the large cost (~$2 billion) and time (~10 years) for bringing a new product to the market in the latest years. At the same time, an alarming number of drug shortages and recalls for quality concerns has been registered by regulators. These events affect companies, from the financial side, but also patients, who might experience increasingly large costs for drugs, or unavailability of essential medicines. The lack of adoption of modern technology and approaches for pharmaceutical development and manufacturing is acknowledged as a main actor for these events. A recent example is the sluggish rollout of COVID-19 vaccines, which has been significantly affected by technological limitations in pharmaceutical development and manufacturing, especially regarding process scale-up. In the early 2000s, a modernization momentum of the sector was initiated, culminated into the Quality-by-Design (QbD) initiative. Within the QbD initiative, regulators defined a novel pharmaceutical development and manufacturing paradigm, rooted in product and process understanding and based on sound science and quality risk management. However, much effort is still needed by the pharmaceutical sector to catch up with other industries on the adoption of modern development and manufacturing technologies. Recently, QbD is evolving towards a new phase, that features the adoption of novel emerging technology, the most important ones being continuous processing, active (i.e., closed-loop) quality control and increased use of mathematics. Mathematical modeling can be used for developing digital tools pivotal to the efficient and rapid implementation of QbD, and its adoption has also been recommended by regulators with dedicated guidelines. Mathematical methodologies can support all stages of the pharmaceutical life cycle, and enable the implementation of continuous processing and active quality control. Within this context, the role and expertise of chemical engineers, especially of the process systems engineering field, are of utmost importance. The objective of this Dissertation is to promote the use of advanced mathematical modeling techniques within pharmaceutical development and manufacturing environments to: i) reduce pharmaceutical development time and cost; ii) increase the efficiency and the robustness of pharmaceutical manufacturing. These objectives are achieved by developing and implementing mathematical methodologies in key areas of pharmaceutical development and manufacturing: operation design, process monitoring and process control. The case studies span across the whole pharmaceutical flowsheet, but are particularly focused on continuous manufacturing processes. Applications of mathematical modeling are specifically addressed to tackle current bottlenecks towards the transition to end-to-end continuous pharmaceutical processing. The results presented and discussed in this Dissertation make several steps forward in the journey to adopt model-based methodologies for modernizing pharmaceutical development and manufacturing. Enabling technologies for the novel Quality-by-Control paradigm and for the transition to end-to-end continuous manufacturing have been developed. In particular, the presented results are expected to promote the adoption of advanced fault detection and diagnosis, digital operation design and closed-loop quality control routines in the pharmaceutical industry.
For pharmaceutical companies, the economic return on investments on research and development has recently been decreasing, mainly due to the large cost (~$2 billion) and time (~10 years) for bringing a new product to the market in the latest years. At the same time, an alarming number of drug shortages and recalls for quality concerns has been registered by regulators. These events affect companies, from the financial side, but also patients, who might experience increasingly large costs for drugs, or unavailability of essential medicines. The lack of adoption of modern technology and approaches for pharmaceutical development and manufacturing is acknowledged as a main actor for these events. A recent example is the sluggish rollout of COVID-19 vaccines, which has been significantly affected by technological limitations in pharmaceutical development and manufacturing, especially regarding process scale-up. In the early 2000s, a modernization momentum of the sector was initiated, culminated into the Quality-by-Design (QbD) initiative. Within the QbD initiative, regulators defined a novel pharmaceutical development and manufacturing paradigm, rooted in product and process understanding and based on sound science and quality risk management. However, much effort is still needed by the pharmaceutical sector to catch up with other industries on the adoption of modern development and manufacturing technologies. Recently, QbD is evolving towards a new phase, that features the adoption of novel emerging technology, the most important ones being continuous processing, active (i.e., closed-loop) quality control and increased use of mathematics. Mathematical modeling can be used for developing digital tools pivotal to the efficient and rapid implementation of QbD, and its adoption has also been recommended by regulators with dedicated guidelines. Mathematical methodologies can support all stages of the pharmaceutical life cycle, and enable the implementation of continuous processing and active quality control. Within this context, the role and expertise of chemical engineers, especially of the process systems engineering field, are of utmost importance. The objective of this Dissertation is to promote the use of advanced mathematical modeling techniques within pharmaceutical development and manufacturing environments to: i) reduce pharmaceutical development time and cost; ii) increase the efficiency and the robustness of pharmaceutical manufacturing. These objectives are achieved by developing and implementing mathematical methodologies in key areas of pharmaceutical development and manufacturing: operation design, process monitoring and process control. The case studies span across the whole pharmaceutical flowsheet, but are particularly focused on continuous manufacturing processes. Applications of mathematical modeling are specifically addressed to tackle current bottlenecks towards the transition to end-to-end continuous pharmaceutical processing. The results presented and discussed in this Dissertation make several steps forward in the journey to adopt model-based methodologies for modernizing pharmaceutical development and manufacturing. Enabling technologies for the novel Quality-by-Control paradigm and for the transition to end-to-end continuous manufacturing have been developed. In particular, the presented results are expected to promote the adoption of advanced fault detection and diagnosis, digital operation design and closed-loop quality control routines in the pharmaceutical industry.

Il contributo all’innalzamento del riscaldamento globale, prodotto dai combustibili fossili è un dei principali problemi ambientali. Le bioenergie potrebbero contribuire enormemente alla riduzione di questo fenomeno, sostituendo in parte i combustibili tradizionali di origine fossile. In questo contesto, può collocarsi il biodiesel prodotto a partire da oli vegetali, rappresentando una valida e strategica alternativa. Il biodiesel è una miscela di metil esteri di acidi grassi, [fatty acids methyl esters (FAME)], normalmente ottenuta tramite reazione di transesterificazione tra oli vegetali e alcol a catena corta in presenza di un catalizzatore acido o basico in catalisi sia omogena che eterogenea. Il biodiesel si colloca tra le materie prime di seconda generazione e può risultare una buona base di partenza per ottenere un biodiesel performante e con un basso costo finale.

La presente tesi verte sull’ implementazione di un sistema automatico per la variazione della velocità della parte rotorica di un mulino per la macinazione fine del tabacco. Si sono quindi analizzate le prestazioni di tale sistema e si è inoltre proposta una strategia migliorativa per applicazioni future. I meccanismi di trasporto esistenti per la movimentazione di materiale in fase solida vengono descritti e se ne evidenzia il ruolo nel processo di macinazione in esame. Dunque, si presenta il processo di fine grinding e le variabili di processo che influenzano la dimensione caratteristica (o particle size) della polvere di tabacco prodotta. Si descrivono quindi l’equipment utilizzato nella macinazione ed i suoi componenti e ci si focalizza in particolare sul cosiddetto “Classifier”, del quale si studia la variazione nel tempo del grado di usura a cui è soggetto. L’esigenza di mantenere il particle size della polvere fine di tabacco entro un intervallo target, viene motivata considerando gli effetti che tale variabile esplica nelle successive fasi di processo. In primis, infatti, il contenuto in acqua (o umidità) della polvere prodotta, che si configura come un parametro critico nelle logiche del processo produttivo, è influenzato dal suo stesso particle size. A questo proposito si sono elaborati ed applicati due modelli fisici per il trasporto di materia che chiariscono tale dipendenza e la fenomenologia di evaporazione dei composti volatili in seguito alla macinazione.

L’obbiettivo di questo progetto di tesi è stato quello di sintetizzare un additivo a base di un copolimero di anidride maleica–alfa-olefine, per il controllo del deposito delle paraffine nella produzione del petrolio. A tale scopo è stata condotta un’approfondita ricerca bibliografica che ha riguardato la letteratura sia accademica che brevettuale, per individuare una prima via di sintesi. Grazie alle informazioni reperite e alla loro elaborazione, è stato possibile effettuare numerose sintesi esplorative dell’additivo stesso e del suo precursore, svolgendo un’approfondita caratterizzazione strutturale e una prima valutazione delle performances applicative di alcune formulazioni, attraverso i test di Cold Finger e Pour Point, ottenendo ottimi risultati. La sintesi individuata è stata anche ottimizzata attraverso lo strumento del D.O.E., considerando come variabili di processo temperatura di reazione, tempo di reazione, rapporto di diluizione e rapporto comonomerico.

In ambito biomedicale una delle applicazioni che ad oggi sta riscuotendo un interesse crescente è lo studio di dispositivi performanti per il rilascio controllato di farmaci. La realizzazione di materiali nanofibrosi a base di polimeri di origine naturale e sintetica costituisce una strada molto interessate. In particolare, la cheratina, che può essere ricavata da un’ampia quantità di sottoprodotti delle industrie zootecniche e tessili, presenta ottima biocompatibilità e caratteristiche che le consentono di svolgere il ruolo di carrier per molteplici tipologie di sostanze. La fragilità e la difficile processabilità della cheratina possono essere migliorate mediante miscelazione con polimeri di origine sintetica, come il poli(butilene succinato) (PBS), un poliestere alifatico biodegradabile e biocompatibile, caratterizzato da un buona stabilità termica e da ampia lavorabilità. Nel presente lavoro di Tesi sono state realizzate miscele e membrane elettrofilate a base di PBS e cheratina a diversa composizione, ed è stato valutato l'effetto della composizione sulle proprietà chimico-fisiche delle membrane elettrofilate e sulla cinetica di rilascio di farmaci. Per prima cosa è stata analizzata la stabilità della cheratina nel solvente; sono state quindi svolte analisi sul comportamento reologico delle miscele in tre rapporti di peso ed i tappetini elettrofilati sono stati caratterizzati da un punto di vista morfologico (SEM), termico (TGA e DSC) e meccanico (prove di trazione e di adesione). Le prove di rilascio sono state effettuate impiegando rodamina, una molecola modello, e le membrane sono state analizzate prima e dopo il rilascio tramite FTIR, per valutare eventuali variazioni compositive. Dai risultati ottenuti, emerge che è stato possibile modulare sia le proprietà delle membrane sia i profili di rilascio, agendo semplicemente sulla composizione delle miscele, ad indicare un’ampia versatilità per applicazioni in ambito di rilascio controllato di farmaco.

Within the stone monumental artefacts artistic fountains are extremely favorable to formation of biofilms, giving rise to biodegradation processes related with physical-chemical and visual aspect alterations, because of their particular exposure conditions. Microbial diversity of five fountains (two from Spain and three from Italy) was investigated. It was observed an ample similarity between the biodiversity of monumental stones reported in literature and that one found in studied fountains. Mechanical procedures and toxic chemical products are usually employed to remove such phototrophic patinas. Alternative methods based on natural antifouling substances are recently experimented in the marine sector, due to their very low environmental impact and for the bio settlement prevention on partially immersed structures of ships. In the present work groups of antibiofouling agents (ABAs) were selected from literature for their ability to interfere, at molecular level, with the microbial communication system “quorum sensing”, inhibiting the initial phase of biofilm formation. The efficacy of some natural antibiofoulants agents (ABAs) with terrestrial (Capsaicine - CS, Cinnamaldehyde - CI) and marine origin (Zosteric Acid - ZA, poly-Alkyl Pyridinium Salts – pAPS and Ceramium botryocarpum extract - CBE), incorporated into two commercial coatings (Silres BS OH 100 - S and Wacker Silres BS 290 - W) commonly used in stone conservation procedures were evaluated. The formation of phototrophic biofilms in laboratory conditions (on Carrara marble specimens and Sierra Elvira stone) and on two monumental fountains (Tacca’s Fountain 2 - Florence, Italy and Fountain from Patio de la Lindaraja - Alhambra Palace, Granada, Spain) has been investigated in the presence or absence of these natural antifouling agents. The natural antibiofouling agents, at tested concentrations, demonstrated a certain inhibitory effect. The silane-siloxane based silicone coating (W) mixing with ABAs was more suitable with respect to ethyl silicate coating (S) and proved efficacy against biofilm formation only when incompletely cured. The laboratory results indicated a positive action in inhibiting the patina formation, especially for poly-alkyl pyridinium salts, zosteric acid and cinnamaldehyde, while on site tests revealed a good effect for zosteric acid.

Within the stone monumental artefacts artistic fountains are extremely favorable to formation of biofilms, giving rise to biodegradation processes related with physical-chemical and visual aspect alterations, because of their particular exposure conditions. Microbial diversity of five fountains (two from Spain and three from Italy) was investigated. It was observed an ample similarity between the biodiversity of monumental stones reported in literature and that one found in studied fountains. Mechanical procedures and toxic chemical products are usually employed to remove such phototrophic patinas. Alternative methods based on natural antifouling substances are recently experimented in the marine sector, due to their very low environmental impact and for the bio settlement prevention on partially immersed structures of ships. In the present work groups of antibiofouling agents (ABAs) were selected from literature for their ability to interfere, at molecular level, with the microbial communication system “quorum sensing”, inhibiting the initial phase of biofilm formation. The efficacy of some natural antibiofoulants agents (ABAs) with terrestrial (Capsaicine - CS, Cinnamaldehyde - CI) and marine origin (Zosteric Acid - ZA, poly-Alkyl Pyridinium Salts – pAPS and Ceramium botryocarpum extract - CBE), incorporated into two commercial coatings (Silres BS OH 100 - S and Wacker Silres BS 290 - W) commonly used in stone conservation procedures were evaluated. The formation of phototrophic biofilms in laboratory conditions (on Carrara marble specimens and Sierra Elvira stone) and on two monumental fountains (Tacca’s Fountain 2 - Florence, Italy and Fountain from Patio de la Lindaraja - Alhambra Palace, Granada, Spain) has been investigated in the presence or absence of these natural antifouling agents. The natural antibiofouling agents, at tested concentrations, demonstrated a certain inhibitory effect. The silane-siloxane based silicone coating (W) mixing with ABAs was more suitable with respect to ethyl silicate coating (S) and proved efficacy against biofilm formation only when incompletely cured. The laboratory results indicated a positive action in inhibiting the patina formation, especially for poly-alkyl pyridinium salts, zosteric acid and cinnamaldehyde, while on site tests revealed a good effect for zosteric acid.

Negli ultimi anni, lo sviluppo di materiali a base proteica per il rilascio controllato di farmaci ha ricevuto grande attenzione. Nel presente lavoro sono stati preparati materiali ibridi compositi, sotto forma di film e nanofibre, costituiti da una matrice di cheratina estratta da lana di pecora e nanoparticelle di idrotalciti Zn/Al intercalate con un antinfiammatorio (diclofenac sodico). Tali materiali compositi sono stati caratterizzati dal punto di vista morfologico e strutturale, sono stati testati in vitro come sistemi per il rilascio controllato di farmaci e confrontati con gli stessi materiali contenenti il farmaco libero (senza idrotalciti). Inoltre, è stata valutata la loro eventuale applicazione nell'ingegneria tissutale e nella medicina rigenerativa, analizzando la capacità di supportare l'adesione e la crescita di cellule fibroblastiche. I risultati ottenuti hanno evidenziato un complessivo effetto di rinforzo delle idrotalciti sui materiali ibridi preparati e il rilascio della quasi totalità del farmaco per diffusione in condizioni fisiologiche durante le prime 160 ore. I test biologici sui film hanno mostrato un significativo aumento della crescita di fibroblasti in 72 ore; test di migrazione cellulare sulle nanofibre ibride saranno oggetto di studi futuri.

Gli impianti dell’industria di processo, durante il loro funzionamento, devono soddisfare determinati requisiti; è necessario, infatti, che vengano soddisfatti requisiti di produzione, al fine di garantire il livello di produzione richiesto e le specifiche di qualità prefissate per il prodotto, e requisiti economici, al fine di ottenere il massimo profitto con il minor costo possibile. Questi requisiti devono essere soddisfatti tenendo in considerazione i vincoli operativi delle apparecchiature, la sicurezza del personale e della popolazione circostante lo stabilimento ed il rispetto dell’ambiente. Per garantire il soddisfacimento dei requisiti sopra elencati è necessario un monitoraggio continuo del processo produttivo, che viene fatto attraverso un sistema di controllo, il quale ha l’obiettivo di contrastare l’effetto delle perturbazioni esterne, mantenendo le variabili di processo entro i limiti prestabiliti. Lo scopo di questo elaborato di tesi è quello di ottimizzare e stabilizzare il circuito di controllo di un processo di essiccamento nell’ambito della produzione di nero di carbonio, riducendo così il quantitativo di prodotto non rispondente ai requisiti di qualità prefissati.

La cellule répond aux contraintes physiques exercées par son environnement par un ensemble de mécanismes regroupés sous le terme de mécanotransduction. Ces processus font appel aux molécules impliquées dans l’adhésion cellulaire, au cytosquelette et au noyau. Ces contraintes environnementales, qu’elles soient liées à la rigidité du support, à sa topographie ou à la nature de sa chimie de surface, vont moduler la morphologie cellulaire et impacter le comportement de la cellule. Afin d’étudier cette influence du support, nous avons ensemencé des cellules souches mésenchymateuses (CSMs) de moelle osseuse (MO) issues d’une culture primaire sur des surfaces de mica vierges ou fonctionnalisées de façon homogène avec des molécules naturelles (la fibronectine FN et le peptide RGD cyclique) ou avec des multicouches de polyélectrolytes PEM (cinq cycles de Chitosan/PAA ou de Chitosan/PSS). Nous avons ensuite étudié la morphologie, la prolifération et la différenciation de ces cellules après 12 jours de culture. Il en résulte que les CSMs de MO adhèrent sur toutes les surfaces, traitées ou non, et bien que leur étalement soit moindre sur les surfaces vierges, elles adoptent une morphologie de type fibroblastique similaire à leur phénotype physiologique. Leur pourcentage de confluence varie significativement en fonction du traitement de surface utilisé. En effet la confluence maximale a été observée pour les surfaces greffées avec la FN (93.25 ± 2.75 %) alors que les surfaces traitées avec les PEM présentent des pourcentages de confluence bien plus faibles (61.00 ± 4.08 % pour le couple chitosan/PAA et 54.75 ± 1.75 % pour le couple Chitosan/PSS), s’expliquant principalement par une latence cellulaire en début de culture. Enfin, les cellules cultivées sur nos surfaces ne réagissent à aucune des trois colorations Oil Red O, Alcian Blue ou Alizarin Red S, suggérant une absence de différenciation dans les voies adipogénique, chondrogénique ou ostéogénique induite par ces surfaces. Ainsi, le contrôle de la chimie du support ne permet pas à lui seul un contrôle de la différenciation cellulaire. Cette étude ouvre la voie à l’étape suivante au cours de laquelle l’influence des supports à chimie et géométrie contrôlées. De même, la souche E.coli (bactérie pathogène) répond aux contraintes physiques et chimiques qui lui ont été imposées. Ces contraintes qu’elles soient liées à la topographie ou la nature de la chimie de surface font appel à des molécules naturelles impliquées dans le comportement des bactéries et leur morphologie en particulier sur leur taille. Pour étudier cet impact, nous avons mis en contact la souche E.coli E2146 avec des surfaces de mica vierges ou traitées de façon homogène ou patternée avec des molécules naturelles (la FN et le peptide RGD cyclique). Ensuite, nous avons étudié le taux de recouvrement et la taille des bactéries. Il en résulte que les bactéries adhèrent sur l’ensemble des surfaces bien que l’adhésion soit moindre sur les surfaces de mica vierges. Leur taux de recouvrement varie significativement pour une surface donnée. En effet, le taux de recouvrement et la taille maximaux sont observés sur des surfaces patternées greffées avec la FN, ce qui prouve leur efficacité et l’impact qu’elles ont sur le comportement de E.coli. Nous avons donc démontré dans ce travail de thèse l’influence des propriétés de surfaces sur la croissance de cellules vivantes telles que les cellules souches ou les bactéries
The cell responds to the physical constraints exerted by its environment by a set of mechanisms grouped under the term of mechanotransduction. These processes involve the molecules involved in cell adhesion, the cytoskeleton and the nucleus. These environmental constraints, whether related to the rigidity of the support, to its topography or to the nature of its surface chemistry, will modulate the cellular morphology and impact the behavior of the cell. In order to study this influence of the support, we have seeded bone marrow mesenchymal stem cells from a primary culture on virgin mica surfaces or functionalized homogeneously with natural molecules (fibronectin and the cyclic RGD peptide) or with polyelectrolyte multilayers (five cycles of Chitosan/PAA or Chitosan/PSS). We then studied the morphology, proliferation and differentiation of these cells after 12 days of culture. As a result, bone marrow mesenchymal stem cells adhere to all surfaces, whether treated or not, and although they are less spread on virgin surfaces, they adopt a fibroblastic type morphology similar to their physiological phenotype. Their percentage of confluence varies significantly depending on the surface treatment used. Indeed the maximum confluence was observed for the surfaces grafted with fibronectin (93.25 ± 2.75%) whereas the surfaces treated with the polyelectrolyte multilayers have much lower confluence percentages (61.00 ± 4.08% for the chitosan/PAA couple) and 54.75 ± 1.75% for the Chitosan/PSS couple), mainly due to cell latency at the beginning of culture. Finally, cells cultured on our surfaces do not respond to any of the three Oil Red O, Alcian Blue or Alizarin Red S stains, suggesting a lack of differentiation in the adipogenic, chondrogenic or osteogenic pathways induced by these surfaces. Thus, the control of the support chemistry alone does not allow control of cell differentiation. This study paves the way for the next step in which the influence of controlled chemistry and geometry media will be studied. Similarly, the E. coli strain (pathogenic bacterium) responds to the physical and chemical constraints imposed on it. These constraints, whether related to the topography or the nature of surface chemistry, involve natural molecules involved in the behavior of bacteria and their morphology, in particular their size. To study this impact, we contacted E.coli strain E2146 with virgin mica surfaces or treated homogeneously or patterned with natural molecules (fibronectin and cyclic RGD peptide). Then we studied the recovery rate and the size of the bacteria. As a result, the bacteria adhere to all surfaces although adhesion is less on virgin mica surfaces. Their recovery rate varies significantly for a given area. Indeed, the recovery rate and the maximum size are observed on patterned surfaces grafted with fibronectin which proves their effectiveness and the impact they have on the behavior of E. coli. We have therefore demonstrated in this thesis the influence of surface properties on the growth of living cells such as stem cells or bacteria

Questa relazione finale è incentrata sul lavoro sperimentale richiesto dalla collaborazione con l’azienda Natural Salumi ed ha come obiettivo principale quello di verifica dei parametri qualitativi e compositivi di una nuova tipologia di salume in fase di studio. L’azienda ha infatti messo a punto un nuovo “prodotto funzionale” addizionando componenti aventi attività nutraceutica al salame ottenuto da sole parti magre di suino (tipo NaturalFetta) e si propone di arricchire il proprio prodotto con acidi grassi polinsaturi della serie omega-3 (da olio di semi di lino), noti per gli effetti benefici esercitati sulla salute umana. Sul prodotto di nuova formulazione si effettueranno sia la determinazione della percentuale lipidica mediante metodo ufficiale Soxhlet ed automatizzato Soxtec, al fine di individuare il quantitativo totale della parte grassa, che una caratterizzazione del profilo quali-quantitativo in acidi grassi, fondamentale per verificare la conformità con i requisiti indicati dal Reg. 1924/06 (e successivi come il Reg. UE 432/2012) previsti per le indicazioni da inserire in etichetta (claims) per i prodotti arricchiti con acidi grassi polinsaturi (PUFA). La determinazione del profilo in acidi grassi e, nello specifico, del contenuto in acido -linolenico, sarà realizzata mediante gascromatografia previa estrazione della frazione lipidica dei salumi con metodo di Folch modificato, che prevede un'estrazione solido-liquido. La concentrazione di acido alfa-linolenico sarà inoltre monitorata durante tutto il periodo di shelf-life del prodotto (45 gg) al fine di valutare eventuali variazioni durante la conservazione. Per soddisfare quest’ultima finalità, le analisi saranno eseguite sia all’inizio (T0) che alla fine (T1) della vita commerciale del prodotto. Le stesse analisi verranno inoltre condotte sia sul prodotto a formulazione classica che su un prodotto del tutto simile, commercializzato da un’altra azienda e considerato come leader di mercato. In relazione ad un possibile aumento di ossidabilità della frazione lipidica, sarà realizzato un controllo dei parametri chimici, qualitativi e compositivi, con particolare riferimento ai prodotti di ossidazione del colesterolo (date le loro implicazioni in ambito biomedico). La maggiore presenza in formulazione di acidi grassi polinsaturi potrebbe infatti favorire un incremento dei COPs (Cholesterol Oxidation Products), che saranno separati, identificati e quantificati mediante la procedura SPE/GC-MS (estrazione e purificazione in fase solida accoppiata ad analisi gascromatografica con rivelazione mediante spettrometria di massa).

La vulcanizzazione è un processo che trasforma la gomma (naturale o sintetica) in un prodotto durevole dotato di proprietà meccaniche superiori. L’agente vulcanizzante per eccellenza è lo zolfo; lo stato dell’arte del processo prevede l’utilizzo di acceleratori ed attivatori per massimizzare i risultati, la qualità del prodotto ed il tempo impiegato. Nell’industria degli pneumatici spesso si lavora con miscele polimeriche per poter conferire al materiale finale tutte le proprietà desiderate. Una delle principale conseguenze della presenza di miscele è la disomogenea ripartizione degli agenti vulcanizzanti in esse. Difatti, è stato mostrato come gli agenti vulcanizzanti si ripartiscano nelle diverse prima che la vulcanizzazione abbia luogo. Si osserva quindi un gap tra le proprietà meccaniche teoricamente raggiungibili e quelle reali del manufatto. Il nostro progetto di ricerca mira a contenere la diffusione degli acceleranti primari di vulcanizzazione. La strategia seguita è ispirata al drug delivery: gli acceleranti vengono incapsulati in un materiale in grado di limitarne la diffusione fino al momento in cui la vulcanizzazione ha luogo. Il materiale scelto per l’incapsulamento è l’etilcellulosa, in quanto possiede delle temperature di rammollimento confrontabili con quelle del processo di vulcanizzazione. Inoltre è un materiale economico, diffuso e non tossico. Sono stati studiati, per confronto, anche altri materiali come il polimetilmetacrilato ed il policarbonato. L’accelerante incapsulato è il N-tert-butil-benzotiazol-2-sulfenamide (TBBS). È stato ottimizzato un metodo in emulsione per la produzione delle capsule, ed è un metodo semplice, efficace, facilmente scalabile ed adattabile a diversi tipi di incapsulante e incapsulato. I test in fase di vulcanizzazione, tuttavia, evidenziano che la tenuta delle capsule non è adeguata. Non si osservano, infatti, delle differenze usando l’accelerante incapsulato o meno. Siamo riusciti a ricondurre l’inefficacia delle capsule ad un fenomeno di collasso strutturale associato alla fusione dell’accelerante. Abbiamo quindi sviluppato un semplice metodo di reticolazione: l’etilcellulosa viene prefunzionalizzata con un epossido, e la reticolazione viene conclusa con un trattamento termico sulle capsule ottenute. In questo modo la stabilità termica delle capsule è preservata. Sorprendentemente, il materiale reticolato accelera notevolmente il processo di vulcanizzazione, anche a basse temperature. Questo è in disaccordo con quanto aspettato. Tuttavia, possiamo ipotizzare che la polarità dell’etilcellulosa faccia fungere l’etilcellulosa stessa da centro di aggregazione per il pacchetto vulcanizzante. Questo farebbe sì che attorno alle capsule si crei una sovrassaturazione di agenti vulcanizzanti, rendendo immediato il processo. Questo ultimo comportamento è ancora oggetto di studio.
Vulcanization is a process that converts rubber – natural or synthetic – into more durable objects with superior mechanical properties. Sulfur is the most used curing agent, but in the actual state-of-the-art processes new components – accelerators and activators – have been introduced to maximize the quality of the product and, meanwhile, decreasing the curing time. In tire industry is very common to work with polymer blends to achieve otherwise inaccessible properties. The main drawback is that the curatives can selectively diffuse into one phase, according to their partition coefficient. This result in a non-homogeneous vulcanization and in a gap between theoretical and real mechanical properties. Our project face this issue using a drug-delivery-inspired process. The accelerator is enclosed in a capsule made of a material that hinders its diffusion at temperature lower than the vulcanization one. We chose ethylcellulose as encapsulating material, since its softening point is compatible with the vulcanization temperatures. We used N-tert-butyl-benzothiazole-2-sulfenamide (TBBS) as accelerator. We optimized an emulsion process for the capsule production; in particular, this is a simple, easily scalable process, which can be extended to different core and encapsulating materials. However, the vulcanization test in rubber blends shows that the capsules are inefficient. In fact, there are no differences in terms of kinetics using the encapsulated accelerator or the pristine one. We recognized that the capsules are intrinsically thermally instable; in fact, the vulcanization temperatures are higher than the melting point of the accelerator, and its melting causes the capsules collapse. To overcome this problem we developed an innovative crosslinking procedure. Ethylcellulose is prefunctionalized with an epoxy; the obtained capsules are crosslinked with a thermal treatment, which complete the reaction of the epoxy with ethylcellulose. The crosslinked capsules are now thermally stable, and no collapse is observed when the temperature is increased. However, the crosslinked capsules cause a dramatic acceleration of the vulcanization kinetics in the rubber blends, even at low temperatures. We hypothesize that, due to its polarity, ethylcellulose dredges all the polar components around the capsules, saturating the surrounding region with curatives. When TBBS leaks out of the capsule, it reacts immediately. Currently, this effect is still under observation.

Un processo industriale è costituito da una serie di operazioni unitarie tra loro integrate, aventi come obiettivo finale quello di realizzare un prodotto finito a partire da determinate materie prime. Durante il normale funzionamento un impianto industriale deve essere in grado di gestire le differenti condizioni dinamiche cui è sottoposto per effetto di perturbazioni esterne, che tendono a spostare i processi dalle condizioni stazionarie; in aggiunta può essere necessario cambiare le condizioni operative per realizzare differenti tipologie di prodotti. L'obiettivo del sistema di controllo del processo è quello di mantenere le variabili di processo pari ai valori desiderati, al fine di ottenere un prodotto conforme alle specifiche e minimizzare la produzione fuori qualità. In questo contesto si inserisce la presente attività di tesi, che ha come scopo l’ottimizzazione del sistema di controllo di una linea di produzione di nero di carbonio. Il lavoro di tesi è così strutturato. Dopo il capitolo 1, avente carattere introduttivo, nel capitolo 2 si descrive la realtà operativa del gruppo chimico a cui appartiene il sito produttivo dove si trova la linea di produzione analizzata. Nel capitolo 3 sono illustrate le tecniche statistiche utilizzate nell’ambito del controllo del processo. Nel capitolo 4 è spiegato che cosa è un sistema di controllo di processo. Il capitolo 5 contiene un approfondimento sulle logiche di controllo applicate nell’industria di processo. Nel capitolo 6 è mostrata l’ottimizzazione della linea di processo in questione. Infine, il capitolo 7 contiene le considerazioni conclusive.

I An ECD investigation aiming at assessing the critical main-chain length for peptide helix formation in water solution is reported. To this goal, it was synthesized by a solution step-by-step protocol a complete series of N-terminally acetylated, C-terminally methoxylated oligopeptides, characterized only by alternating Aib and Ala residues, from the di- to the nonamer stage. All of these compounds were investigated by ECD in the far-UV region in water solution as a function of chemical structure, the presence/absence of the ester moiety at the C-terminus and temperature. The critical main-chain lengths for 310- and α-helices, although still formed to a partial extent, in aqueous solution are six and eight residues, respectively. II A whole series of AuNps was synthesized from mercaptopropionic derivatives of alternating Aib/Ala peptide series. Our studies established the occurrence of chiroptical properties in peptide-coated 2 nm diameter gold nanoparticles. The peptides induce a chiral effect onto the plasmon resonance band detectable via ECD. Such a behavior appears to be strongly influenced by the secondary structure assumed by the coating peptides. III The water solubility displayed by alternating Aib/Ala peptide series was investigated. The evidences of the formation of self-assembled structures in water, likewise responsible for the unexpected solubility properties, are presented. These peptide aggregates are spherical, with diameters up to 100 nm. They can also incorporate other molecular structures of relevant size, such as Au nanoparticles. Such systems may widen the number of applications currently accessible to self-assembled aggregates in the fields of biomedicine and materials science. IV Two new Ca-tetrasubstituted a-amino acids bearing two identical azobenzene-derived side chains have been synthesized. Photo-reversible isomerization process was detected. Intermediate chiral species are generated during the isomerization process driven by iii light. Diastereomers where generated when a chiral protein amino acid was inserted. The conjugation of one of the bis(azobenzene)-derived amino acids with different metal nanoparticles allowed the isomerization process to be detected even in solid state. Furthermore, the Au-derived nanoparticles exhibit a magnetic susceptibility dependence on the light-driven isomerization state that can be simply detected by 1H-NMR spectroscopy. Based on this behavior, these amino acids are of relevant potential for the development of a novel class of materials. V A series of Ferrocene and Pyrene labelled helical peptides containing one or more 4- amino-1,2-dithiolane-4-carboxylic acid (Adt) residues have been synthetized. Such peptides have been prepared to be employed in the formation of SAMs over gold surfaces (by means of linkage with the dithiolane Adt side chains) for electrochemical applications. In particular, the peptides have been designed for ensuring: (i) an highrigidity of the peptide scaffold and (ii) a parallel disposition of the peptide axle respect the metal surface. Conformational characterizations and CV tests on a Ferrocene binding 6-mer are presented. Preliminary experiment on the photo-current generation property has also been performed.
I Al fine di determinare la lunghezza critica per la formazione di eliche peptidiche in acqua è stata effettuata un’ indagine ECD su una serie completa di oligopeptidi acetilati composti da residui alternati di L-Ala ed Aib e terminante come estere metilico. Tali peptidi, pur non presentando funzionalità cariche o polari, risultano essere idrosolubili. L’ indagine È stata effettuata nell’ UV da 250 a 190 nm, ovvero nella regione dello spettro dicroico sensibile alla conformazione peptidica. Anche l’ assenza dell’ estere metilico (residuo C-terminale come carbossile o carbossilato) e la variazione della temperatura sono state studiate per osservare gli effetti sulla confomazione. Le lunghezze critiche per la transizione da struttura random ad elica 310 e da elica 310 ad elica risultano essere l’ esapeptide e l’ ottapeptide rispettivamente. II Una serie completa di nanoparticelle d’ Oro sono state sintetizzate dai peptidi della serie alternata Aib/L-Ala descritta, opportunamente funzionalizzati con acido 3-mercapto propionico. Lo studio ha stabilito la presenza di effetti chirali indotti sull’ oro dalla presenza dei leganti peptidici. Tale effetto È stato determinato via indagine ECD ed È dipendente dalla struttura secondaria del peptide e dall’ amminoacido più prossimo in catena nei leganti peptidici. III Le cause della solubilità in acqua evidenziata dai peptide della serie È stata indagata. Sono stati supposti dei meccanismi di auto aggregazione in acqua. Un’ indagine TEM ha confermato tale ipotesi. Nel caso dell’ undeca-peptide Z-Ala3-(AibAla)4OMe tali aggregati risultano sferici e di dimensioni dell’ ordine dei 100 nm. Ne È stata inoltre studiata la capacità di inglobare nanoaparticelle di Oro. Tali sistemi possono ampliare le applicazioni di sistemi auto assemblanti nei campi della biomedicina e dei materiali. IV Due nuovi ammino acidi Cα tetrasostituiti recanti due unità azobenzeniche identiche in catena laterale sono stati sintetizzati. Sono stati studiati processi di foto-isomerizzazione reversibili. E’ stata inoltre determinata la formazione di speci intermedie chirali durante tale processo. Tali amminoacidi sono stati accoppiati a residui chirali (L-Leu). In tal caso, durante il processo di isomerizzazione È stata riscontrata la formazione di speci diastereoisomeriche. Tali amminoacidi recanti due unità azobenzeniche sono stati quindi opportunamente derivatizzati per la formazione di nanoaparticelle metalliche. In particolare, il processo di foto-isomerizzazione È stato testato in fase solida su nanoparticelle di Oro con tali ammino acidi come leganti. E’ stato quindi svolto uno studio sulle proprietà magnetiche di tali nanoparticelle e la sua dipendenza dal processo di foto-isomerizzazione delle catene laterali dei leganti. V Sono stati sintetizzati una serie di peptidi elicoidali rigidi funzionalizzati con unità Pireneacetica o Ferrocenica all’ estremità N-terminale. La rigidità di tali eliche peptidiche È stata ottenuta utilizzando residui alternati di L-Ala ed Aib. Tali peptidi sono stati sintetizzati per formare SAM su superfici di Oro per applicazioni in elettrochimica. A tale scopo, i peptidi contengono anche uno o più residui di acido 4-ammino-1,2-ditiolano-4-carbossilico (Adt), un residuo in grado di legare l’ Oro grazie al legame disolfuro in catena laterale. Tale tipo di legame assicura inoltre una disposizione parallela delle catene peptidiche rispetto la superficie. Sono stati sintetizzati due decapeptidi recanti due Adt in posizione 1 e 8 (due giri esatti in un’ elica) ed una serie di esapeptidi recanti gli Adt in posizione 1 e 4 (un giro di elica 310). Tale geometria consente il legame più efficiente possibile alla superficie, in quanto i residui di Adt si trovano dallo stesso lato dell’ elica. I prodotti finali sono stati chimicamente caratterizzati. Sono state condotte approfondite indagini conformazionali su due esapeptidi. Su un esapeptide contenente Ferrocene sono stati inoltre condotti degli esperimenti di voltammetria ciclica e di generazione di foto-corrente.

It is known by foul control paint and Impressed Current Cathodic Protection system producers that paints can fail in proximity of the anodes. This failure is well known in industrial field, but does not represent a structural problem. As a matter of fact, paint recovery is performed within routinary docking operations. Within this framework, it is interesting to evaluate the behavior of new generation biocide-free foul control paints under a chemical stress resembling that near ICCP anodes, where seawater turns acidic and chlorinated. Data in this area have not been already studied nor published. The values of free chlorine and pH produced at anodes, to which paints are exposed, were obtained experimentally. Two biocide free paints, a foul release (FR) and an amphiphilic self-polishing (SP), were chosen for testing on these conditions. Paints were exposed to a 3x3 matrix of 'pH/free-Cl' different conditions. After 3 months of immersion in the selected environments, a physical-chemical characterization was performed through: visual inspection, detachment area analysis, thickness variation, contact angle variation, profilometry and IR. Laboratory and field tests were finally performed to evaluate the foul-control properties after treatments. Results showed that the degradation is mainly induced by free chlorine oxidation, and acidity strengthens the chemical attack. Both paints in the harshest condition were disbonded. Foul release paint seems generally more stable but detaches easily from the primer, while the amphiphilic SP is apparently less prone to detachment from the primer, but exhibits modification of its physical properties. Foul-control properties did not show a substantial drop after the conditioning treatment, but the tests reported detachment of both paints in conditions in which it was not previously observed.

Ce projet consiste à fabriquer et à étudier des micelles à la fois biocompatibles et capables de relarguer des molécules volatiles bioactives à partir d’une solution aqueuse sous l’influence de stimuli extérieurs tel que le pH, la température ou la concentration. Pour atteindre ce but, nous avons étudiés un nouveau type d’objets micellaires qui sont formés par l’auto-assemblage d’amphiphiles covalents dynamiques (DCAs), des surfactants peu onéreux formés de l’association moléculaire réversible d’un bloc hydrophile et d’un bloc hydrophobe. Ces systèmes peuvent relarger une large gamme de fragrances à partir d’une solution, que cela soit à partir du coeur hydrophobe de la micelle ou alors à partir de l’amphiphile (profragrance). Ils ont aussi été capables de stabiliser en solution des aldéhydes sensibles à l’hydrolyse
This project relies on the simple design and the study of biocompatible responsive micelles, capable of releasing a hydrophobic bioactive volatile from an aqueous solution and that, depending on the modulation of external factors such as pH, temperature, and concentration. To reach this goal, we have taken advantages of a new kind of micellar objects that are formed by the efficient self-assembly of biodegradable Dynamic Covalent Amphiphiles (DCAs), low cost surfactants that are made by the reversible molecular association of one hydrophilic and one hydrophobic block. These systems can release a broad variety of fragrances from solution, both from the hydrophobic micellar core or directly from the amphiphile (profragrance). It also proved able to stabilise some sensitive aldehydes in solution

During the past years, the considerable need in the domain of communications for more potent photonic devices has focused the research activities into the nonlinear optical (NLO) materials which can be used for modern optical switches. In this regard, a lot of research activities are focused on the organic materials and conjugated polymers which offer more advantages compared to the inorganic ones. On this matter, poly(3-alkylthiophene) (P3AT), an organic conjugated polymer, can be investigated as potential optical material with in particular the focus on the NLO properties such as the first- and second-hyperpolarizability, β and γ respectively. The activities carried out at the Laboratory of Polymer Synthesis of the KU Leuven, during the master's thesis work, focused on the study of conjugated polymers in order to evaluate their NLO properties for the future purpose of applications in optical systems. In particular, three series of polythiophenes functionalized with an alkyl side chain in the 3-position were synthesized: poly(3-hexylthiophene) (P3HT), poly[3-(2-ethylhexyl)thiophene] (P3EHT) and random copolymer of the two regio-isomers of P3HT. They were made in order to study the influence of molar mass, branching and regio-irregularity on the γ-value. The Kumada catalyst transfer condensative polymerization (KCTCP) and the Pd(RuPhos)-protocol were used for the polymerizations in order to have control over the molar mass of the growing chain and consequently to obtain well-defined and reproducible materials. The P3AT derivatives obtained were characterized by gel permeation chromatography (GPC), spectroscopic techniques (1H-NMR, UV-Vis) and the γ-value was investigated using the third-harmonic scattering (THS) technique. In particular, the THS technique is useful to investigate the optical behavior of the series of polymers in solution.

The aim of the research work was the synthesis and characterization of new A-B-A triblock copolymers of polylactic acid (PLLA), whose chemical structure was ad hoc designed for the preparation of: micro- and nanoparticles for controlled drug delivery; polymer film with elastomeric properties for soft tissue engineering application. The A block consists of PLLA, while the B block (previously synthesized by the research group of Prof. Lotti, co-supervisor of this work) is an equimolar copolymeric system poly(butylene/triethylene succinate) with different sequences length: block copolymer (long sequences of both co-units)and random copolymer (very short sequences of both co-units)The random B block was also used for the realization of a high molecular weight A-B-A triblock copolymer, obtained by chain extending the low molecular weight A-B-A triblock. The different molecular architecture proved to be an effective tool in modulating the hydrophilicity, the crystallinity degree and the kinetics of the hydrolytic degradation of the final material. The results indicate that it is possible to modulate the release kinetics by acting both on the architecture of the B block and on the size of the particles. Furthermore, the mechanical properties of the high molecular weight A-B-A triblock copolymer are significantly improved with respect to those of the homopolymer, making the material a very interesting candidate for soft tissue engineering: the elastic modulus is reduced by two orders of magnitude, and the elongation at break increases from 2 to 100%. Regarding the kinetics of the hydrolytic resorption, the findings show the rate of degradation is slowed down by copolymerization. Lastly, it is worth mentioning the improvement by copolymerization of the thermal stability (important parameter for the processability of a biomaterial) of PLLA.

Afin de déterminer la longueur critique de formation d’hélices peptidiques dans l’eau, on a effectué des mesures de dichroïsme circulaire sur une série de peptides acétylés, composés de résidus alternés de L-Ala et Aib. Les longueurs critiques pour les transitions de structure random d’hélice 310 et de 310 à α sont l’hexapeptide et l’octapeptide. On a synthétisé une série complète de nanoparticules d’or utilisant les peptides de la série alternée Aib/L-Ala, après fonctionnalisation avec l’acide 3-mercaptan-propionique. L’étude a investigué la présence d’effets chiraux sur l’or causés par la présence des ligands peptidiques. Cet effet, déterminé par ECD, dépend de la structure secondaire du peptide et de l’aminoacide dans le ligand le plus proche de l’or. On a synthétisé deux nouveaux aminoacides avec des fonctionnalités azo-béniques sur la chaîne latérale pour des études de photo-isomérisation réversibles. Ces aminoacides ont été incorporés dans des nanoparticules métalliques. Une étude sur les propriétés magnétiques dépendant de l’isomérisation a été effectuée. On a synthétisé une série de peptides hélicoïdaux rigides avec des pyrènes ou ferrocènes à l’extrémité N-terminale. Ces peptides ont été préparés pour la formation des SAM sur des surfaces d’or pour applications en électrochimie, et contiennent un ou plusieurs résidus d’acide 4-amino-1,2-dithiolane-4-carboxylique (Adt), un résidu qui peut lier l’or par des liaisons disulfures. Pour un hexapeptide avec un ferrocene, on a fait des mésures électrochimiques pour tester les propriétés de oxydoréduction du ferrocene lié au peptide et de génération de photo-courant
An ECD investigation aimed at assessing the critical main-chain length for peptide helix formation in water was performed on a series of acetylated peptides composed of alternating Aib and Ala residues. The critical main-chain lengths for 310- and α-helices, although still formed to a partial extent, in aqueous solution are six and eight residues, respectively. A series of AuNps were synthesized from mercaptopropionic acid derivatives of alternating Aib/Ala peptides. Our studies established the occurrence of chiroptical properties in peptide-coated 2 nm diameter gold nanoparticles. Such behavior is strongly influenced by the secondary structure assumed by the coating peptides. Two new Cα-tetrasubstituted α-amino acids bearing azobenzene-derived side chains have been synthesized for photo-isomerization studies. These amino acids were incorporated into metal nanoparticles. The Au-derived nanoparticles exhibit magnetic susceptibility dependent on the light-driven isomerization. A series of ferrocene and pyrene labelled helical peptides containing one or more 4-amino-1,2-dithiolane-4-carboxylic acid (Adt) residues have been synthesized. These peptides were prepared for the formation of SAMs on gold surfaces for electrochemical applications. Preliminary experiments on the photo-current generation properties of a ferrocene labeled hexamer have been performed

Nell’ultimo periodo, si è sviluppato un forte interesse nella produzione di materiali a base proteica per il settore biomedicale e cosmetico, in particolare per il rilascio controllato di farmaci. In questo studio sono stati sviluppati, tramite elettrofilatura, dei materiali nanocompositi, costituiti da una matrice di cheratina, ottenuta da lana, e PLA caricata con grafene ossido e con Rodamina-B, un indicatore particolarmente usato in chimica analitica per valutare il rilascio di determinati sistemi. Tali materiali, caratterizzati morfologicamente e strutturalmente, sono stati testati in vitro come sistemi per il rilascio controllato di farmaci, usando la Rodamina per la maggiore facilità di rilevazione, valutando soprattutto l’influenza del grafene ossido sull’entità del rilascio. I risultati ottenuti hanno evidenziato come l’ossido di grafene influisca in maniera significativa sull’entità del rilascio, rallentando la quantità di Rodamina rilasciata nelle prime 48 ore. Studi per l’applicazione di questi materiali nell’ingegneria tissutale e nella medicina rigenerativa saranno oggetto di studi futuri.

2015 - 2016
Purpose of the PhD thesis was to develop dedicated lipid nanostructured vectors with tailored features (in terms of size, surface charge, load capability, stimuli responsive ability and stability) through the design of novel production processes expressly developed for nutraceutical and therapeutic agents encapsulation. The preliminary performed review of the main processes used for liposomes production have underlined that the majority of the conventional and more innovative methods adopted show a number of drawbacks such as few product volumes in output (directly linked to the impossibility in scaling up the process), high energy consumption, long times of production together with the use of toxic solvents and other process drastic conditions. To the light of these literature findings and with the aim to produce nanostructured vectors through more sustainable processes, two novel techniques, sharing the ultrasound technology as process intensification tool used in particles size reduction and homogenization operations, were designed and developed to respond to the needs of a better process performance, improving its efficiency and cutting down energy consumption. At first, based on the use of ultrasound as alternative energy resource, a solid particles size reduction process was developed and coupled with the bench scale conventional Thin Film Hydration (TFH) method. This technique provides the generation of a lipid film which is formed after solvents evaporation through the use of a rotary evaporator. The dried film is then hydrated, spontaneously producing micrometric vesicles characterized by the presence of several bilayers. Then the method was revisited by adding the ultrasound assisted step developed in order to produce, in a versatile manner, structures with the desired dimension (on micro/nano scale), starting from the micrometric ones. Four are the main sections composing the set-up to apply this innovative protocol: a feeding section, a solvent evaporation section, a liposomes production/homogenization section and a recovery section. In particular, the homogenization section is composed of a 3 mm sonication tip (operative frequency 20 kHz) which acts on micrometric vesicles sample aliquots. Subsequently to the realization of the production bench scale apparatus, the phenomenology connected to the vectors constitution was investigated and a dynamic model able to describe the curvature of a lipid bilayer under the effect of ultrasonic energy was then proposed and tested. In that regard, starting from micrometric vesicles, the ultrasound energy is used to break the lipid bilayer into smaller pieces, then these pieces close themselves in spherical structures producing small vesicles. Moreover the role of several process parameters were also elucidated. Once established its reliability and due its great potential in reducing time spent, without compromising the integrity of the liposomal systems produced (in terms of structure and load), the ultrasound intensification tool was also used for liposomes homogenization operation during vesicles production through a similmicrofluidic approach. As a matter of fact, in order to produce higher volumes of lipid vectors, potentially on production scale, directly with nanometric size, a simil-microfluidic apparatus was expressly designed and fabricated, overcoming the limitations of the small output volumes typical of the conventional bench scale techniques. There are five main sections composing the realized apparatus: a feeding section, a pumping section, a production section, an homogenization section and a recovery section. In particular the homogenization section is composed of a 6 mm sonication tip (operative frequency 20 kHz) directly immersed in the entire hydroalcholic solution containing nanoliposomes. As previously done, the phenomenological aspects involved in vectors constitution were investigated for this new adopted set-up. In particular, the reproduction of the phenomenology connected to the vesicles formation through a microfluidic approach was achieved by the use of constructive expedients (millimetric diameter of tubes, peristaltic pumps, injection needle). Particularly, nanostructured vectors formation 3 happens at the interfaces between the alcoholic and water phases, when they start to interdiffuse in a direction normal to the liquid flow stream; changes in flow conditions result in size variations of the insertion section of the organic phase reflecting on the vesicles dimensional features. In that regards, taking into account that size and size distribution are key parameters determining liposomes performance as carrier systems in both pharmaceutical and nutraceutical applications, a control on the produced nanoliposomes dimensional features was demonstrated by tuning the volumetric flow rates and the lipids concentration process parameters. In particular, it was understood that increasing the ratio between the water volumetric flow rate to the lipids-ethanol volumetric flow rate the liposomes dimensional distibution increases; on contrary, ultrasonic energy enhances the homogenization of the hydroalcoholic bulk and, as expected on the bases of previous studies conducted on smaller volumes, its duty cycle application efficaciously promoted a better vesicles dimensional distribution. This result was also confirmed by working at equal flow rates but at different lipid concentrations. Finally, the developed similmicrofluidic apparatus, working at room conditions and in absence of toxic solvents, makes nanoliposomes production a safe and low cost process, highly productive due to the use of ultrasound which was demonstrated to be a scalable means for process intensification. By using the two developed experimental set-up, several classes of liposomal structures were formulated and produced to respond to specific requests of nutraceutical and pharmaceutical applications. Through the ultrasound assisted tool at first coupled with the conventional THF method and subsequently used as integrant part of the homogenization section of the simil-microfluidic apparatus, different active molecules were successfully encapsulated in lipid nanostructured vectors solving the critical issues linked to their naked administration and transport through biological membranes. In particular, nanoliposomes containing vitamins with different hydrophobicity (α-tocopherol, ergocalciferol, vitamin B12) and ferrous sulfate, with highly interesting features for nutraceutical market, were produced achieving stable loaded nanoliposomes with high encapsulation efficiencies and good dimensional features. In details, for vitamins-nanoliposomes productions, neuter vesicles with micrometric size, ranging from 2.9 μm to 5.7 μm, were produced, obtaining, after sonication in duty cycle, small vesicles in the average range of 40 nm to 51 nm in size. High encapsulation efficiency (e.e.) was obtained in both micrometric vesicles, with a e.e. % of 72.0 ± 00 % for vitamin B12, 95.0 ± 7.07 % for α-tocopherol and 81.5 ± 2.12 % for ergocalciferol, and small vesicles, with an e.e. % of 56.2 ± 8.51 % for vitamin B12, 76.3 ± 14.02 % for αtocopherol and 57.5 ± 13.9 % for ergocalciferol (the higher the vitamin hydrophobicity, the higher the encapsulation efficiency). Finally, a comparison between vitamin B12 load achievable with the developed technique and the vitamin load achievable by breaking unloaded preformed liposomes (conventional approach) showed an increase of encapsulation efficiency in small vesicles from 40% to 56.2 %, confirming the effectiveness of the pointed out technique. Regarding the ferrous sulfate-nanoliposomes, their massive production was possible due to the similmicrofluidic approach with a precise control on particles size and size distribution. In particular, the effect of different weight ratios of iron to the total formulation components (0.06, 0.035, 0.02 and 0.01 iron/total components weight ratio) on the final vesicles encapsulation efficiency was investigated obtaining with the last formulation an high encapsulation efficiency (up to 97%). In general, ferrous sulfate loaded nanoliposomes, negative charged, with good dimensional features (127135 nm for not sonicated and 48-76 nm for sonicated liposomes) were successfully produced through the use of the simil-microfluidic method developed, obtaining an elevated process yield if compared to the classical bench scale techniques (THF and Ethanol Injection). For pharmaceutical purposes, anionic nanoliposomes containing a new synthetized peptide (KRX29) for a not conventional heart failures therapy and new, cutting edge, nucleic acids based therapeutics agents (NABDs), used in gene therapy, were successfully produced. 4 Regarding KRX29-nanoliposomes production, micrometric particles of 7.2-11.7 μm were obtained and sized with the use of the developed ultrasound assisted process thus achieving 22 – 35 nm vesicles. The effect of liposomes charge on both peptide encapsulation and recovery efficiencies was at first studied, showing an higher encapsulation efficiency (about 100%) achieved (both in small and large vesicles) by using the higher charge ratio formulation (13:1 (-/+)). Viceversa, the ability to recover the entrapped peptide was obtained for loaded systems (both in small and large vesicles) at the lower charge ratio formulation (1:1 (-/+)). As the charge ratio, also the peptide concentration showed influence on the liposomes encapsulation efficiency. For NABDs complexes production, at first preliminary experiments in which dsDNA was used to simulate the structure of siRNA molecule were done by testing different dsDNA/DOTAP lipid charge ratio (3:1, 5:1 and 7:1 (+/-)) in order to achieve the higher dsDNA encapsulation efficiency in the smaller carrier possible. DOTAP phospholipid was used due to its positive charge. The performed activities have confirmed the versatility of the ultrasound assisted technique for producing micro (2.2 – 2.9 μm) and nano lipid vectors (28 - 56 nm) encapsulating NABDs. In particular, the charge ratio (+/-) variation from 3:1 to 7:1 (+/-) by changing the amount of positive lipid (DOTAP) used in liposome preparation have allowed to an improved e.e. wich was 64 % and 100 % respectively for small and large vesicles by using the 7:1 (+/-) charge ratio. Starting from these preliminary tests, siRNAs-nanoliposomes complexes were produced for the inhibition of E2F1 protein expression, studied as a potential way to treat colorectal cancer associated to Inflammatory Bowel Diseases. By the TFH/sonication technique nanoliposomes with 33-38 nm range size and 100% siRNA encapsulation efficiency were obtained. The produced loaded nanoliposomes demonstrated a very low excellent uptake in the cultured human colon mucosa tissues. A remarkable anti-E2F1 expression effect after siE2F1-1324-nanoliposome samples transfection has been demonstrated also in a dynamic human model such the colon tissue microenvironment (i.e. an 80.5% reduction of E2F1 expression respect to the basal tissue was achieved in patient 4), a clear tendency to respond in a patient-dependent way was observed. All the achieved results highlight the potentiality of the purposely designed nanoliposomes in deliver, in a controlled manner, different active molecules for both pharmaceutical and nutraceutical purposes. The formulative and the chemical engineering approaches adopted in this thesis for nanostructured vectors production respectively enhance the product quality (nanoparticles with tailored features) and make the process more attractive in terms of improved safety and reduced costs. [edited by Author]
XV n.s. ( XXIX ciclo)

The aim of this doctoral project has been centered on the development of innovative green synthetic methods able to govern the key physico-chemical properties of noble metal nanoparticles (NPs). To fully uncover the potential of metallic NPs, it is necessary to finely control the shape of nanomaterials while keeping the ultra-small characteristics, in order to achieve superior efficiency (per mass unit), selectivity and enhanced activity in catalytic processes. Size and shape of the nanomaterial together with the capping agents govern the surface properties and all the processes happening at the surface, such as catalysis. Different shapes offer great versatility to tune the nanocrystal (NCs) catalytic properties, which are dictated by surface facets. Green synthetic procedures have been developed to obtain pure, monodisperse, citrate-capped Pt and Pd NPs with accurate control on their size and the shape, without the use of polymers, surfactants and organic solvents. For Pd NPs, different geometrical shapes were achieved, such as icosahedrons, cubes, rods and wires while maintaining the thickness of 7 nm and length ranging from 38 to 470 nm (in the case of rods and wires) and the size (in the case of cubes and icosahedron) below 10 nm. These engineered nanomaterials exhibited good biocompatibility along with interesting enzymatic and catalytic properties, due to the absence of sticky molecules, high quality of the surface and the removal of toxic reagents. Moreover, a green synthetic procedure has been developed to obtain ultra-small Pt NCs by combining a strong and a weak reducing agent in aqueous environment in a single reaction vessel in only 10 minutes. NCs with size as low as 2.8 nm and high percentage of {111} surface domains have been achieved. These NCs have been physico-chemically and electrochemically characterized, disclosing significant perspectives for their use as innovative electrocatalysts or nanozymes in portable diagnostics.