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Yang, Hongta. "Fundamentals, preparation, and characterization of superhydrophobic wood fiber products." Thesis, Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/24796.
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Thesis (M. S.)--Chemical Engineering, Georgia Institute of Technology, 2008.<br>Committee Chair: Yulin Deng; Committee Member: Jeffery S. Hsieh; Committee Member: Sujit Banerjee; Committee Member: Zhong Lin Wang.
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Garoff, Niklas. "The Friction between Paper Surfaces." Doctoral thesis, Stockholm, 2002. http://www.diva-portal.org/kth/theses/abstract.xsql?dbid=3415.
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Piltonen, P. (Petteri). "Prevention of fouling on paper machine surfaces." Doctoral thesis, Oulun yliopisto, 2013. http://urn.fi/urn:isbn:9789526202877.
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Abstract Fouling in papermaking causes major economic drawbacks due to downtime of process and paper quality defects. The surface fouling is a complex phenomenon in a paper making process, which is affected by several interconnected factors such as process environment changes from wet to dry with increasing temperature along with the variety of sticky materials present in paper raw materials. These impurities, such as waxes, coating binders, hot melts and pressure-sensitive adhesives have a tendency to attach to the surfaces of machinery during paper production and cause surface fouling. The focus of this thesis was on the mechanisms of sticking and surface fouling on a paper machine surfaces caused by problematic sticky organic materials. The sticking potential of six styrene–butadiene latices varying in carboxylation degree, crosslinking density and viscoelasticity and one polyacrylate pressure sensitive adhesive were studied using a cylindrical probe tack method under dry and aqueous conditions. Sticking potential was measured using low and high energy surfaces as an adherent. Also a new practical method for the on-site evaluation of nonstick properties of cylinder coating materials was developed. This method enables monitoring the condition of the coating during its life cycle and also provides the opportunity to compare the performance of different drying cylinder coating materials. The research performed clearly showed that low viscoelastic modulus of latex increases sticking tendency. The results also showed that presence of water can either increase or decrease adhesion depending on the moisture content ant the physic-chemical properties of sticky materials. A low surface energy coating strongly decreases sticking compared to a high energy surface and have a lower susceptibility to fouling in the dry environment. In aqueous conditions, the use of high-energy surfaces decreases adhesion of latices due to their strong interaction with water. Also, the results indicated that carboxylation decreases sticking potential of latex in both dry and aqueous environments<br>Tiivistelmä Paperikoneiden likaantuminen aiheuttaa suuria tuotannollisia menetyksiä johtuen tuotantoprosessin katkoksista ja paperin laadun ongelmista. Paperikoneen pintojen likaantuminen on monimutkainen prosessi, johon vaikuttavat monet toisistaan riippuvat tekijät ja siten likaantumisilmiötä on vaikea hallita. Paperin raaka-aineet voivat sisältää epäpuhtauksia, kuten vahoja, kuumasulate- ja tarraliimoja, jotka tarttuvat paperikoneen pintoihin aiheuttaen niiden likaantumista. Lisäksi paperin prosessiympäristö muuttuu märästä kuivaan valmistusprosessin edetessä ja lämpötilan kasvaa samanaikaisesti. Tässä väitöskirjassa on kuvattu paperikoneen pintojen likaantumisen mekanismeja ja erityisesti orgaanisten lika-aineiden tarttumista. Tutkimuksessa selvitettiin probe tack -menetelmää käyttäen kuuden erilaisen styreeni-butadieenilateksin ja polyakrylaattitarraliiman tarttuvuutta matalan ja korkean pintaenergian pinnoilla sekä kuivissa että märissä olosuhteissa. Työhön oli valittu latekseja, joiden karboksylointiaste, ristisilloitustiheys ja viskoelastiset ominaisuuden olivat erilaisia. Lisäksi väitöskirjatyössä kehitettiin paikan päällä suoritettava mittausmenetelmä paperikoneen kuivaussylinterien pinnoitteen puhtaana pysyvyyden määrittämiseksi. Tällä menetelmällä voidaan mitata pinnoitteiden kuntoa niiden elinkaaren aikana ja myös vertailla erilaisia pinnoitteita keskenään. Tutkimuksen tulokset osoittivat, että styreeni-butadieenilateksien matala kimmokerroin lisää niiden tarttumista paperikoneen pinnoille. Veden läsnäolo voi joko lisätä tai vähentää tarttumista riippuen veden määrästä ja lika-aineiden fysiokemiallisista ominaisuuksista. Myös paperikoneen pinnoitteen pintaenergia vaikuttaa tarttuvuuteen. Paperikoneen pinnoitteiden pieni pinta-energia vähentää tarttumista kuivissa olosuhteissa, kun taas korkean pintaenergian pinnoitteet vähentävät lateksien tarttuvuutta vesiolosuhteissa. Lisäksi lateksien karboksylointi vähentää niiden tarttumista sekä kuivissa että märissä olosuhteissa
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Zhao, Boxin Pelton Robert H. "The interactions of pressure sensitive adhesive with paper surfaces." *McMaster only, 2004.
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Li, Lester. "Structural considerations for superhydrophobic and superoleophobic surfaces." Diss., Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/52914.
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Highly fluid repellent have application in many industries ranging from marine to biomedical due to their self-cleaning antifouling properties. The development and implementation of these superhydrophobic (water contact angle >150 degrees ) and superoleophobic (oil contact angle > 150 degrees ) surfaces were studied in this thesis. We focused our studies on paper as a substrate for these superhydrophobic and superoleophobic surfaces. Cellulose based paper is a biodegradable, inexpensive material that is ideal for disposable use applications. Applying an oxygen plasma etching technique combined with the deposition of a fluoropolymer from a pentafluoroethane precursor, superhydrophobic paper can be attained. This superhydrophobic paper is functionalized by printing wax islands onto the surface, thereby creating areas of high fluid adhesion. These wax functionalized sheets are used to sample droplets from bulk droplets, with the sampled volume being controlled by the hysteresis of the wax island. Disposable biomedical devices can be envisioned from these wax designs. While these superhydrophobic surface excel at repelling water, they continue to readily absorb water. Formation of paper that is both superhydrophobic and superoleophobic, or superamphiphobic, is accomplished through a combination of steps: mechanical fiber refining, solvent exchange processing and plasma treatment. The fiber refining creates nano-scale fibrils that are separated in the solvent processing. Subsequent plasma treatment of oxygen etching and fluoropolymer deposition creates superamphiphobic paper, exhibiting contact angles of > 150 degrees for water, ethylene glycol, motor oil and n-hexadecane. Further studies were conducted to increase the strength of these superamphiphobic sheets by using layered paper. Development of superhydrophobic paper from a hydrophilic diamond-like carbon surface coating was also demonstrated. When combined with oxygen plasma etching, diamond-like carbon coated paper sheets attain superhydrophobic properties similar to fluoropolymer coated sheets. Based on the knowledge gained from the studies on paper, superhydrophobic surfaces are created on 304 and 316 stainless steels. Samples are etched in hydrofluoric acid and then passivated in nitric acid to create the necessary surface structure. Deposition of fluoropolymer onto the etched samples yields superhydrophobic properties.
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Aulin, Christian. "Preparation, characterisation and wetting of fluorinated cellulose surfaces." Licentiate thesis, Stockholm : Royal Institute of Technology. Department of Fibre and Polymer Technology, Division of Fibre Technology, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4587.
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Öhlund, Thomas. "Coated Surfaces for Inkjet-Printed Conductors." Licentiate thesis, Mittuniversitetet, Institutionen för tillämpad naturvetenskap och design, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:miun:diva-16449.
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In this thesis, a number of commercially available paper substrates of various types are characterized and their characteristics related to the performance of inkjet-printed conductors using silver nanoparticle ink. The evaluated performance variables are electrical conductivity as well as the minimum achievable conductor width and the edge raggedness. It is shown that quick absorption of the ink carrier is beneficial for achieving well defined conductor geometry and high conductivity. Surface roughness with topography variations of sufficiently large amplitude and frequency is detrimental to print definition and conductivity. Porosity is another important factor, where the characteristic pore size is much more important than the total pore volume. A nearly ideal porous coating has large total pore volume but small characteristic pore size, preferably smaller than individual nanoparticles in the ink. Apparent surface energy is important for non-absorbing substrates but of limited importance for coatings with a high absorption rate.Additionally, a concept for improving the geometric definition of inkjet-printed conductors on nonporous films has been demonstrated. By coating the films with polymer–based coatings to provide a means of ink solvent removal, minimum conductor width were reduced a factor 2 or more.Intimately connected to the end performance of printed conductors is a well adapted sintering methodology. A comparative evaluation of a number of selective sintering methods has been performed on paper substrates with different heat tolerance. Pulsed high-power white light was found to be a good compromise between conductivity performance, reliability and production adaptability.The purpose of the work conducted in this thesis is to increase the knowledge base in how surface characteristics of papers and flexible films affect performance of printed nanoparticle structures. This would improve selection, adaption of, or manufacturing of such substrates to suit printed high conductivity patterns such as printed antennas for packaging.<br>I denna avhandling har ett antal kommersiellt tillgängliga papper av olika typ karaktäriserats och deras egenskaper relaterats till prestandan på inkjet-tryckta elektriska ledare tryckta med silvernanopartikelbläck. De undersökta prestandavariablerna är elektrisk ledningsförmåga samt ledarnas minimala linjebredd och kantjämnhet. Det visas att en snabb absorption av bläckets lösningsmedel är gynnsam för både väldefinierad ledningsgeometri och elektrisk ledningsförmåga. Ytråhet med topografiska variationer med tillräckligt stor amplitud och spatiell frekvens korrelerar negativt med tryckdefinition och ledningsförmåga. Porositet är ytterligare en viktig faktor, där karaktäristisk porstorlek är avsevärt viktigare än total porvolym. Nära ideala egenskaper hos en porös bestrykning synes vara en mycket hög total porvolym men med små individuella porer, med fördel mindre än de minsta metallpartiklarna i bläcket. Ytenergi är mycket betydelsefull för icke-absorberande substrat men tappar nästan all sin betydelse för bestrykningar med snabb absorption.Ett koncept för att förbättra den geometriska definitionen på inkjet-tryckta ledare på icke-porösa flexibla filmer har visats. Genom att bestryka filmerna med vissa polymerbaserade material och därmed införa en mekanism för separering av lösningsmedel och partiklar så reducerades ledarnas minimibredd med en faktor 2 eller mer.Intimt förknippad med den slutliga elektriska prestandan på tryckta ledare är också en väl anpassad sintringsmetodik. En jämförande utvärdering av ett flertal selektiva sintringmetoder har genomförts på papper med olika värmetålighet. Pulsat vitt ljus med hög effekt bedömdes som en bra kompromiss mellan elektriska prestanda, tillförlitlighet och anpassningsbarhet för produktionsmiljö.Nyttan med arbetet som presenteras i denna avhandling är att öka kunskapsbasen för hur pappers och flexibla filmers ytegenskaper påverkar prestandan på inkjet-tryckta nanopartikelstrukturer. Detta möjliggör bättre urval, anpassning av, eller tillverkning av sådana substrat för att passa tryckta mönster med hög konduktivitet; som till exempel tryckta antenner på förpackningar.
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Hansuebsai, A. "An investigation of the optical profile properties (smoothness) of paper substrates including the effects on smoothness of solvent penetratation and with particular reference to lithographic." Thesis, University of the Arts London, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.234271.
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Fivaz, Erika. "Evaluation of joint formation on cellulosic surfaces." Thesis, KTH, Materialvetenskap, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-277912.
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Environmental issues are more and more present in our societies. Pollution engendered by plastic waste have drastically increased these past decades, causing several threats to the ecosystem. Therefore, the need of new biodegradable plastics to replace the actual petroleum-based ones is urgent. Cellulose could be a potential substitute since it is a biopolymer, abundant on Earth. However its properties have to be enhanced to be competitive towards actual plastics. The aim of the project is therefore to get a better understanding of cellulose-cellulose interactions. It focuses on the adhesion between cellulosic surfaces. Contact adhesion measurements have been performed on cellulose beads, with different treatments. All the beads had the same size and same concentration. Some of them were native whereas others were charged (600 µeq/g). Half of the native beads were surface modified with a starch coating or a Layer by Layer technique using cationic starch and an anionic polyelectrolyte (EXPN64 or FennoBond 85E). The project included preparation of the surface modified beads, pull-off tests, where load and position were recorded as a function of time, as well as measurements of the contact area. It was found that a higher energy was needed to separate charged and surface modified beads, especially the ones modified with EXPN 64, compared to native beads. The project have also shown that the types of beads influenced the contact area and the strength. However a trend was sometimes difficult to find. The data and results obtained in this project could be further re-used to enlarge the study field and investigate the influence of other parameters (size, concentration) on the adhesion of cellulose beads.<br>Miljöfrågor är mer och mer närvarande i våra samhällen. plastavfall har ökat drastiskt de senaste decennierna och orsakat flera hot mot ekosystemet. Därför är behovet av ny biologiskt nedbrytbar plast för att ersätta de petroleumbaserade brådskande. Cellulosa kan vara en potentiell ersättare eftersom det är en biopolymer. Emellertid måste dess egenskaper förbättras för att vara konkurrenskraftiga gentemot petroleumbaserad plast. Syftet med projektet är därför att bättre förstå cellulosa-cellulosa-interaktioner. Den fokuserar på vidhäftningen mellan cellulosaytor. Kontaktvidhäftningsmätningar har utförts på cellulosapärlor med olika behandlingar. Alla pärlor hade samma storlek och koncentration. Vissa av dem var naturliga medan andra laddades (600 µeq/g). Projektet inkluderade beredning av ytmodifierade pärlor, utdragningstester, där belastning och position registrerades som en funktion av tiden, samt mätningar av kontaktområdet. Det visade sig att högre energi behövdes för att separera laddade och ytmodifierade pärlor, särskilt de modifierade med EXPN 64, jämfört med tonativa pärlor. Projektet har också visat att typerna av pärlor påverkade kontaktområdet och styrkan. Men en trend var ibland svår att hitta. Uppgifterna och resultaten som erhållits i detta projekt kan vidare användas för att förstora studiefältet och undersöka påverkan av andra parametrar (storlek, koncentration) på vidhäftningen av cellulosapärlor.
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Illergård, Josefin. "Development of New Bacteria-Reducing Surfaces." Licentiate thesis, KTH, Fibre and Polymer Technology, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-10586.
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<p>In recent years, antibacterial surfaces have been a subject of increased interest. Especiallyinteresting are non-leaching, contact-active surfaces that physically disrupts the bacterialcell using immobilised cationic polymers. Thus the risks of bacterial resistance and discharge of hazardous biocides is minimised. The assembly of such surfaces is elaborate andusually involves organic solvents. Here, polyelectrolyte multilayers (PEM) are proposed as an effective surface modification method, with an overall goal of producing antibacterial cellulose fibres. The PEM process is based on physical adsorption of oppositely charged polymers in aqueous solutions. Multilayers were formed with the bactericidal polymer polyvinylamine (PVAm) and polyacrylic acid. PVAm compounds with hydrophobic modificationswere applied as well, as they possess increased antibacterial activity in solution.</p><p>In this work, the multilayer formation was studied on model surfaces of silicone oxide and glass in order to obtain fundamental knowledge of the polymer system. QCM-D and reflectometry, which detect total mass including bound water and polymer mass only, respectively, were used to analyse the layer formation. Salt-concentrations were varied at 1, 10 or 100 mM NaCl. A stepwise multilayer formation with exponential-like polymer adsorption but with decreasing water content for each layer was seen at all salt concentrations.A higher salt concentration resulted in an increased adsorbed mass. No significant differences in adsorption between the modified and unmodified PVAm could be detected. AFM imaging applied to multilayers having nine layers showed large surface aggregates under high salt conditions for the C6-modified PVAm. Dynamic light scattering showed that the polymer occurred as single molecules in solution; hence it was concluded that theaggregation is surface-associated.</p><p>The multilayers were then tested for bacterial growth inhibition. The relative bacterial inhibition was time-dependent, as the surface was saturated with bacteria over time. After two hours, a maximal inhibition of 99 % could be observed for the multilayers. After eight hours, a moderate inhibition of less than 40 % was detected. Using multilayers affected the results positively compared to single layers. After three layers, though, no further reductionwas seen. Viability staining of the surface-adhered bacteria revealed that the adhered bacteria had intact membranes. Therefore, the microbiological properties of the multilayers can at this point be described more as growth-inhibiting by bacterial adhesion effectsthan as biocidal. However, this work has shown the importance of combining surface characterisation and microbial testing to understand the bacteria-surface interaction.</p><br>Biointeractive fibres
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Preston, Janet Susan. "The influence of coating structure on the print gloss of coated paper surfaces." Thesis, University of Bristol, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.393086.
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Ostrander, Colleen Francis. "Skin, Landscape, and the Mind: An Examination of Surfaces." VCU Scholars Compass, 2006. http://scholarscompass.vcu.edu/etd_retro/77.
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My thesis researched memory and perception through an examination of surfaces. Acting as skin, boundary, veil, or terrain, the surfaces I created revealed imprints and residues that offered information used to clarify distorted perceptions. I attempted to locate evidence in parts of my body, and in physical matter, that contained a record of history. The work was often site specific, with the wall playing an intrinsic role in the construction of these pieces, made of paper, thread, and wax. Their surfaces referenced landscapes of the earth and of the body, a mental terrain shaped over time by the paths of repetitive thoughts and the steady advance of emotional forces. In the end, the surfaces asked more questions than they could answer, and it was this mystery within the surfaces that I would devote myself to. The work embraced ambiguity, shadows, and what was hidden beneath the surface.
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Werner, Oskar. "Computer Modelling of the Influence of Surface Topography on Water Repellency and a Study on Hydrophobic Paper Surfaces with Partly Controlled Roughness." Thesis, Linköping University, The Department of Physics, Chemistry and Biology, 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-2614.
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<p>A computer model based on minimization of the free energy, capable to predict contact angles and spreading transitions between Wenzel and Cassie mode for drops placed on surfaces with different topography were implemented in matlab. Simulations were compared with experiments documented in the literature. These showed that reported transitions between Cassie and Wenzel mode can be explained by minimization of the free energy. In this report, a study on the possibility of constructing water repellent paper surfaces with a combination of treatment with octadecyltrichlorosilane and topography changes, is included.</p>
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Gustafsson, Emil. "Tailoring adhesion and wetting properties of cellulose fibers and model surfaces." Licentiate thesis, KTH, Fiberteknologi, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-91296.
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The layer-by-layer (LbL) technique was used to modify the surface of cellulose fibers by consecutive adsorption of poly(allylamine hydrochloride) (PAH) and poly(acrylic acid) (PAA) followed by a final adsorbed layer of anionic paraffin wax colloids. Paper hand sheets made from the modified fibers were found to be highly hydrophobic with a contact angle of 150°. In addition to the significantly increased hydrophobicity, the sheets showed improved mechanical properties, such as a higher tensile strength. Heat treatment of the prepared sheets further enhanced both the mechanical properties and the hydrophobicity. These results demonstrate the flexibility and robustness of the LbL technique, which allows us to combine the known adhesive effect of PAH/PAA LbL films with the functionality of wax nanoparticles, creating a stronger and highly hydrophobic paper. It was further observed that LbL modified sheets without wax also displayed increased hydrophobicity when heat treated. The mechanism was studied through model experiments where LbL films of PAH/PAA were assembled on flat non-porous model cellulose surfaces. Contact angle measurements showed the same trend due to heat treatment of the model films, although, the absolute value of the contact angles were smaller. Analysis using the highly interfacial sensitive vibrational sum frequency spectroscopy technique showed an enrichment of CH3 groups (from the polymer chain ends) at the solid/air interface. These results indicate that during the heat treatment, a reorientation of polymer chains occurs to minimize the surface energy of the LbL film. In the second part of this work, the adhesive interactions between the main constituents of wood fibers were studied using high-resolution measuring techniques and well-defined model films of cellulose, hemicellulose and lignin. Successful surface modification of polydimethylsiloxane (PDMS) caps, needed in the Johnson-Kendall-Roberts (JKR) measuring methodology, by LbL deposition of nanofibrillated cellulose (NFC) and poly(ethylene imine) (PEI) allowed for the first known all-wood biopolymer JKR measurements of the adhesion between cellulose/cellulose, cellulose/lignin and the cellulose/glucomannan surfaces. The work of adhesion on loading and the adhesion hysteresis were similar for all three systems, suggesting that adhesion between the different wood biopolymers does not differ greatly.<br><p>QC 20120314</p>
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Gantenbein, Daniel. "Development of mineral particle surfaces for the adsorption of pitch from wood processing and recycling of paper." Thesis, University of Plymouth, 2012. http://hdl.handle.net/10026.1/1175.
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During the production of paper in paper mills, detrimental wood resin is released into the water circuit of the mill during the pulping process of the wood into fibres. This wood resin, termed pitch, can detrimentally deposit on the paper and on the paper machine equipment. The deposits mark the paper or can lead to a tear of the paper web involving a loss of output and a reduction in paper quality. Furthermore, the wood resinous compounds in paper mill effluents need to be reduced in order to minimise their toxic effects on water organisms. Talc has been the benchmark for many years as a mineral additive in pitch control. Since the papermaking process has changed over the years, the concept of mineral addition needs to be redefined and adopted towards the new circumstances. By understanding the fundamentals behind the adsorption of wood resin compounds from aqueous systems on to talc new mineral additives can be developed. A model for the determination of the aspect ratio of platy and rod-like particles has been developed, based on commonly available characterisations such as particle size, specific surface area and shape. It was found that the adsorption capacity of a mineral is directly proportional to its specific surface area, but only within its mineral family. Including the effect of surface hydrophilicity and hydrophobicity allowed fine tuning of the adsorption capacity of newly developed calcium carbonate grades. Furthermore, size exclusion effects, in porous, high surface area modified calcium carbonate, were seen to hinder complete coverage of the surface area by wood resin. With increasing pH, the adsorption efficiency of talc for colloidal wood resin was found to decrease. Under these alkaline conditions, which are common in modern paper making processes, talc preferentially adsorbed dissolved species. The use of the newly developed surface treated and modified calcium carbonates allowed more efficient adsorption of the colloidal fraction and, therefore, represent an efficient alternative to talc in pitch control. An increase in temperature led to an increased adsorption capacity of talc. This observation indicates the type of interaction tat controls the adsorption of hydrophobic pitch particles onto talc, i.e. the entropically favoured release of water from the hydrophobic talc surface as well as the hydrophobic methylene backbone of the hemicellulose.
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Pao, Sheng-Ying (Sheng-Ying Aithne). "Beyond the boundaries of paper : a gesture-sensing pen for interfacing physical content with digitally-augmented surfaces." Thesis, Massachusetts Institute of Technology, 2015. http://hdl.handle.net/1721.1/98655.
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Thesis: Ph. D., Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2015.<br>Page 188 blank. Cataloged from PDF version of thesis.<br>Includes bibliographical references (pages 159-165).<br>Humans are inherently creative and we have the desire to express and communicate. Pen and paper have been effective means of creation, expression, and communication for centuries. Today, technology increasingly permeates our environment but the spread of digital displays makes us more susceptible to passive viewership. What if we could combine the benefits of technology and pen and paper to empower people to become more active creators? This thesis explores new affordances for pens that become an interface to transcend the boundaries of paper through a series of gesture interactions that a) transfer content from the surface of creation (i.e., paper) onto surface of attention (i.e., intended surfaces in the immediate or remote locations); b) enable dynamic interactions across time by allowing users to create and transform static drawings on paper into an animated expression; c) maintain privacy for content creation while allowing users to selectively share only chosen content in real-time; d) explore the impact of gesture embodiment on audience engagement and shift their perspectives from being passive viewers to active creators. A series of usability studies were designed and conducted to evaluate the platforms and to explore how people may expand physical content beyond the boundaries of paper with the system. Beyond laboratory development, this thesis also presents the real-world deployment of the gesture-sensing pen as an interactive installation in a museum exhibition. Potential applications range from collaborative workspaces to participatory art experiences. Issues relating to creative process, sharing and privacy, and usability are examined in light of the interactive nature of the system.<br>by Sheng-Ying Pao.<br>Ph. D.
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Kamal, Alm Hajer. "Interfacial Adhesion Failure : Impact on print-coating surface defects." Doctoral thesis, KTH, Fiber- och polymerteknologi, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-194166.
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The aim of this work was to develop a solid knowledge on formulation effects controlling offset ink-paper coating adhesion and to identify key factors of the coating and printing process affecting it. Focus lay on comprehending the impact of pigment dispersant on ink-paper coating adhesion and ultimately on the print quality of offset prints. The work covers laboratory studies, a pilot coating trial designed to produce coated material with a span in surface chemistry and structure, and an industrial offset printing trial. The lab scale studies quantified ink-paper coating adhesion failure during ink setting with a developed laboratory procedure based on the Ink-Surface Interaction Tester (ISIT) and image analysis. Additional polyacrylate dispersant resulted in slower ink setting and reduced ink-paper coating adhesion, with a dependence on its state of salt neutralisation and cation exchange, mainly in the presence of moisture/liquid water. The industrial printing trial on pilot coated papers was designed to study how these laboratory findings affected full scale offset print quality. These trials confirmed the dispersant-sensitive effect on ink-paper coating adhesion, especially at high water feeds. Evaluation of prints from the printing trial resulted in two fundamentally different types of ink adhesion failure being identified. The first type being traditional ink refusal, and the second type being a novel mechanism referred to as ink-lift-off adhesion failure. Ink-lift-off adhesion failure occurs when ink is initially deposited on the paper but then lifted off in a subsequent print unit. In this work, ink adhesion failure by this ink-lift-off mechanism was observed to occur more often than failure due to ink refusal. Print quality evaluation of the industrial prints suggested that water induced mottle was caused by a combination of ink-surface adhesion failure, creating white spots on the print, together with variation in ink layer thickness due to emulsified ink.<br><p>QC 20161019</p>
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Fulleringer, Nicolas. "Contribution à l'étude des phénomènes de friction : application au matériau papier." Thesis, Grenoble, 2014. http://www.theses.fr/2014GRENI071/document.
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L'optimisation de nombreux procédés technologiques requiert une compréhension approfondie des phénomènes de frottement des papiers. Nous avons donc cherché à mieux comprendre ces phénomènes pour tenter d'améliorer la séparation des enveloppes dans les machines à affranchir. Les méthodes normalisées de mesure du frottement papier-papier se sont tout d'abord avérées limitées en termes de répétabilité et de conditions expérimentales. Nous avons donc développé deux méthodes de mesure, l'une à faible et l'autre à haute vitesses. Nous avons aussi adapté la mesure du frottement aux différents contacts papier rencontrés dans les machines à affranchir. Dans un second temps, nous avons utilisé ces méthodes pour étudier les mécanismes responsables du frottement avec le matériau papier. Nous avons notamment étudié (i) la dépendance du frottement papier-papier à la direction et longueur du déplacement, (ii) l'influence de la température et de l'humidité sur le frottement papier-papier et (iii) les principales caractéristiques frictionnelles des contacts enveloppe-enveloppe, papier-rouleau et papier-patin. Dans un troisième temps, nous avons développé un modèle complet de la séparation des enveloppes dans une machine à affranchir. Cette séparation vise à déplacer, sans l'abimer, l'enveloppe inférieure d'une pile – et uniquement cette enveloppe. Le modèle a permis d'identifier, de caractériser et de proposer une optimisation des principaux paramètres de ce procédé<br>The improvement of numerous technological processes requires a deep understanding of the paper friction phenomena. Thus, we tried to obtain a better understanding of those phenomena to improve the envelopes separation in franking machines. The standad methods for measuring the paper-on-paper friction force appeared to be limited in terms of repeatability and experimental conditions. Thus, we developed two experimental methods, at low and high speeds, respectively. We also adapted the friction measurement methods to the different contacts found in franking machines. We then used those methods to study the mechanisms responsible for the friction with the paper materials. In particular, we studied (i) the dependency of the paper-on-paper friction to the direction and length of the displacement, (ii) the influence of temperature and humidity on the paper-on-paper friction, and (iii) the main frictional properties of the envelope-on-envelope, rollers-on-paper, and pads-on-paper contacts, respectively. To finish with, we developed a model of the envelopes separation inside a franking machine. This process aims at displacing - with no damage - the bottommost envelope of a stack - and only this envelope. The model allowed us to identify, to characterize, and to propose an optimization of the main process parameters
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Picollet, Martine. "Contribution à l'étude de l'imprimabilité des papiers LWC en héliogravure édition." Grenoble INPG, 1997. http://www.theses.fr/1997INPG0038.
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Dans ce travail, nous etudions l'imprimabilite des papiers lwc en heliogravure edition. Les proprietes de surface, la permeabilite et les proprietes electriques des papiers vierges sont caracterisees a l'aide de diverses techniques de mesure. Une relation entre la structure de la couche et la permeabilite du papier couche est mise en evidence. D'autre part, la technique de la chromatographie inverse en phase gazeuse appliquee aux papiers couches permet de determiner de facon satisfaisante leur energie de surface. Les points manquants, les vaguelettes, la transvision et le rendu densitometrique ont ete retenus comme criteres de qualite d'impression. Ils sont analyses visuellement et a l'aide d'appareils de mesure. Grace aux resultats obtenus, il est possible d'identifier les caracteristiques du papier ayant une influence preponderante ainsi que leur importance relative. L'etat de surface du papier mais aussi ses proprietes electriques determinent le nombre de points manquants. Les vaguelettes dependent essentiellement de la regularite de la couverture de couche sur le support fibreux. Les problemes de transvision sont causes principalement par une opacite trop faible du papier. Des experiences complementaires realisees au laboratoire permettent d'ameliorer la comprehension des phenomenes d'interaction encre - papier, qui determinent notamment le rendu densitometrique. Nous montrons l'existence d'une competition entre la penetration de l'encre, liee a la permeabilite du papier, et l'etalement a la surface, qui depend de la mouillabilite mais aussi de la rugosite.
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Charoenpholphibool, Wandee. "The study of paper surface efficiency /." Online version of thesis, 1989. http://hdl.handle.net/1850/11467.
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Marrakchi, Zied. "Valorisation de la fibre d'Alfa." Thesis, Grenoble, 2013. http://www.theses.fr/2013GRENI075.
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Cette thèse s'inscrit dans le contexte de l'exploitation des matériaux bio-sourcés dans des applications à haute valeur ajoutée et vise à valoriser un produit de transformation d'une plante herbacée appelée Alfa ou « Stipa tenacissima », très abondante en Tunisie. L'idée principale de ce travail est d'étudier et d'exploiter les pâtes d'Alfa produites à l'échelle industrielle, dans l'objectif de rechercher de nouvelles voies de valorisation. L'application potentielle envisagée concerne l'utilisation des fibres d'Alfa comme éléments de renfort dans des bio-composites à base de matrices polymères. Après une synthèse bibliographique, la première partie de ce travail a été consacrée à l'étude des tiges et des pâtes d'Alfa (caractérisations chimiques, analyses morphologiques, mesure des charges électriques, cinétiques de raffinage des pâtes, etc.). En outre, l'effet du raffinage sur les propriétés physiques des papiers produits à partir des fibres d'Alfa a été étudié. Dans un second temps, nous nous sommes intéressés à la valorisation des fibres d'Alfa, transformées en papier, comme renfort dans des composites à matrices polymères biodégradables. Nous avons choisi une technique d'imprégnation des papiers préparés dans des solutions de polymères biodégradables pour l'élaboration de ces composites et nous avons étudié deux polymères : la polycaprolactone (PCL) et l'acide L-polylactique (PLLA). Les propriétés structurales, morphologiques, thermiques et mécaniques de ces nouveaux composites ont été analysées et discutées. Par ailleurs, nous avons proposé une méthode originale de modification de surface des fibres d'Alfa selon un protocole simple à trois séquences, combinant un traitement par micro-ondes et un traitement chimique des papiers préparés. Enfin, l'effet de cette modification de surface du renfort sur les propriétés des composites a été évalué et analysé<br>This thesis aims at valorizing herbaceous plant called Alfa or "Stipa tenacissima" in added value application. This raw material is very abundant in Tunisia. Thus, the main idea of this work is to use Alfa fibers as reinforcing elements in polymer matrices-based bio-composites The literature review revealed that this plant has not been extensively studied, which motivated undertaking a comprehensive study of these fibers. Thus, a systematic and deep study of the chemical composition, the morphological properties, the electrical charges, the kinetics of pulp refining as well as the physical properties of the paper produced from these fibers was performed and gave several rational insights on Alfa fibers in the context of papermaking. The second part was devoted to the use of Alfa fibers, as reinforcing fiber mat in composite materials based on biodegradable polymer matrices. In this context, we have chosen an impregnation technique of the prepared paper films in solutions of two biodegradable polymers: polycaprolactone (PCL) and poly-L-lactide (PLLA). The structural, morphological, thermal and mechanical properties of these new composites were analyzed and discussed. In addition, we have proposed an original microwave-assisted grafting of surface chemical modification of Alfa fibers. In this context, stearic acid was used as a coupling agent. Finally, the effect of the surface modification of the reinforcement on composites properties was assessed and analyzed
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Liu, Chung-Ni. "Laboratory investigation of the effect of the dampening solution on the loss of surface strength of coated paper /." Online version of thesis, 1993. http://hdl.handle.net/1850/11983.
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Sananpanichkul, Wanna. "Paper and printed paper surface characteristics studied using an optical method." Thesis, Open University, 1993. http://oro.open.ac.uk/54812/.
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A non-contact optical method for evaluating surface characteristics is reviewed. The optical reflectance instrument has been improved to be able to evaluate printed surfaces. Experiments were conducted with solid prints prepared on two types of papers printed with a heatset yellow ink. Both paper surfaces and printed surfaces are characterized into two regions: above the surface plane resulting in macrosmoothness (Sm) and below the surface plane resulting in microsmoothness (Su). For a better understanding of such optical print smoothness, a printed surface model is proposed based on Barkas' classical model. It is generally known that the qualities of a print are determined by the materials and their interactions in the process, therefore the formation of printed surface characteristics has been discussed in relation to ink and paper interaction. Print smoothness is influenced by the uncompressed paper roughness and porosity, which determine the degree of ink penetration and ink distribution on the surface. Offset lithographic printing has been the most widely used printing process, printing onto paper substrates. To achieve good press performance and high quality prints, the ink has to emulsify a certain amount of fountain solution; maintenance of this ink and water balance is, therefore, very important. The effects of fountain solution emulsified in the ink on print smoothness wp-re investigated. A range, of varying amounts of fountain solutions, was emulsified in a heatset yellow ink using a high speed laboratory mixer; these 'emulsion inks' were printed as soon as possible after preparation. It was found that the print smoothness in macro regions, for both uncoated and coated papers, decreased significantly. In addition, an unpigmented ink system was employed to verify the role and the effects of pigment in the emulsification mechanism on print smoothness. The results indicated that pigment is the dominant contributor, to a smoothness decrease; and the pigment effect arises from the amount of fountain solution emulsified in the ink. It has become important to measure print quality directly and quantitatively in the developments of ink, paper and printing technologies. This method makes it possible to measure print smoothness as a criterion for print quality.
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Skedung, Lisa. "Tactile Perception : Role of Friction and Texture." Doctoral thesis, KTH, Yt- och korrosionsvetenskap, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-103916.
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Tactile perception is considered an important contributor to the overall consumer experience of a product. However, what physical properties that create the specifics of tactile perception, are still not completely understood. This thesis has researched how many dimensions that are required to differentiate the surfaces perceptually, and then tried to explain these dimensions in terms of physical properties, by interconnecting human perception measurements with various physical measurements. The tactile perception was assessed by multidimensional scaling or magnitude estimation, in which methods human participants assign numbers to how similar pairs of surfaces are perceived or to the relative quantity of a specified perceptual attribute, such as softness, smoothness, coarseness and coolness. The role of friction and surface texture in tactile perception was investigated in particular detail, because typically tactile exploration involves moving (at least) one finger over a textured surface. A tactile approach for measuring friction was developed by means of moving a finger over the surfaces, mounted on a force sensor. The contribution of finger friction to tactile perception was investigated for surfaces of printing papers and tissue papers, as well as for model surfaces with controlled topography. The overarching research goal of this thesis was to study, systematically, the role of texture in tactile perception of surfaces. The model surfaces displayed a sinusoidal texture with a characteristic wavelength and amplitude, fabricated by surface wrinkling and replica molding techniques. A library of surfaces was manufactured, ranging in wavelengths from 270 nm up to 100 µm and in amplitudes from 7 nm up to 6 µm. These surfaces were rigid and cleanable and could therefore be reused among the participants. To my knowledge, this is the first time in a psychophysical experiment, that the surface texture has been controlled over several orders of magnitude in length scale, without simultaneously changing other material properties of the stimuli. The finger friction coefficient was found to decrease with increasing aspect ratio (amplitude/wavelength) of the model surfaces and also with increasing average surface roughness of the printing papers. Analytical modeling of the finger’s interaction with the model surfaces shows how the friction coefficient increases with the real contact area, and that the friction mechanism is the same on both the nanoscale and microscale. The same interaction mechanism also explains the friction characteristics of tissue paper. Furthermore, it was found that the perceptions of smoothness, coarseness, coolness and dryness are satisfactorily related to the real contact area at the finger-surface interface. It is shown that it is possible to discern perceptually among both printing papers and tissue papers, and this differentiation is based on either two or three underlying dimensions. Rough/smooth and thin/thick were the two main dimensions of surface feel found for the printing papers, whereas friction and wavelength were strongly related to the perceptual cues employed in scaling the model surfaces. These experimental results support the duplex theory of texture perception, which holds that both a “spatial sense”; used to discriminate the roughest textures from the others, and a “vibration sense”; used to discriminate among the smoother textures, are involved. The perception of what is considered rough and smooth depends on the experimental stimulus context. It is concluded that friction is important for human differentiation of surface textures below about 10 µm in surface roughness, and for larger surface textures, friction is less important or can even be neglected. The finger friction experiments also allowed the following conclusions to be drawn: (i) The interindividual variation in friction coefficients is too large to allow direct comparison; however, the trends in relative friction coefficients for a group of participants are the same. (ii) Lipids are transferred to the test surface of study, and this lowers the friction. (iii) Many of the studies point to a characteristic frequency during sliding of about 30 Hz, which is both characteristic of the resonance frequency of skin and the expected frequency associated with the fingerprints. (iv) The applied load in surface interrogation is in fact regulated in response to the friction force. The limits in tactile perception were indirectly researched by similarity scaling experiments on the model surfaces. Wrinkle wavelengths of 760 nm and 870 nm could be discriminated from untextured reference surfaces, whereas 270 nm could not. The amplitude of the wrinkles so discriminated was approximately 10 nm, suggesting that nanotechnology may well have a role to play in haptics and tactile perception.<br>Taktil perception bidrar starkt till den sammantagna upplevelsen av en produkt, men hur materials olika ytegenskaper påverkar och styr perceptionen är ännu inte helt klart. Den här avhandlingen undersöker hur många och vilka egenskaper som är viktiga när känslan mellan två ytor jämförs. Tillvägagångssättet är tvärvetenskapligt där fysikaliska mätningar kopplas ihop med perceptions mätningar där människor används som instrument. Två typer av perceptionsförsök har utförts, multidimensionell skalning där försökspersoner sätter siffror på hur lika två ytor känns, samt magnitud estimation där i stället intensiteten på specifika perceptuella storheter som t.ex. upplevt lenhet, upplevd mjukhet och upplevd strävhet bedömdes. Eftersom taktil perception innebär kontakt samt relativ rörelse mellan hud och ytor, har fokus i avhandlingen varit att undersöka hur friktion och ytans struktur (ytråhet) påverkar och bidrar till den taktila perceptionen. Förutom fysikaliska mätningar på friktion och ytstruktur har värmekonduktivitet, mjukhet samt olika standard mätningar inom pappersindustrin mätts. En metod för att mäta friktion mellan ett finger och olika ytor har utvecklats för att i möjligaste mån återspegla friktionskomponenten i upplevt taktil perception. Friktionskoefficienter beräknades och jämfördes mellan alla ytor. De stimuli som har studerats är tryckpapper och mjukpapper samt modellytor, gjorda för att systematiskt undersöka hur ytstruktur påverkar perceptionen. Tillverkningsmetoden för modellytorna valdes så att ytorna var tåliga och kunde tvättas och därmed återanvändas. Strukturen på ytorna bestod av ett vågformat mönster där våglängden varierade mellan 270 nm och 100 µm och amplituden mellan 7 nm och 6 µm. Enligt vår vetskap är det första gången som strukturer i de här skalorna har gjorts utan att samtidigt ändra andra material egenskaper. Friktionskoefficienten minskade med ökad kvot mellan amplituden och våglängden på modellytorna samt med ytråheten på tryckpappren. En analytisk modell tillämpades på kontakten mellan ett finger och ytorna som visade att friktionskoefficienten beror av den verkliga kontaktarean. För de mycket grövre mjukpappren uppmättes inga stora skillnader i friktion förmodligen för att kontakarean mellan de olika mjukpapprena var lika. Den faktiska kontakarean visade sig också vara viktig för perceptionen av lenhet, strävhet, torrhet och svalhet. Det visade sig vara en stor perceptuell skillnad mellan olika typer av tryckpapper och mjukpapper utifrån hur stimuli placerade sig på en taktil karta. För de tre materialen användes enbart två alternativt tre egenskaper hos materialet för att särskilja mellan alla olika par. För tryckpapper verkade en viktig dimension kunna beskrivas av alla de perceptuella och fysikaliska egenskaper som har med kontaktarean att göra, d.v.s. lenhet, svalhet, torrhet, ytråhet, värmekonduktivitet samt friktion. För att taktilt särskilja mellan olika ytor där bara strukturen är varierade, kunde friktion och våglängden relateras till spridningen i kartan. Båda studierna stödjer duplex theory of texture perception, där ett spatialt sinne används för att särskilja en av de grövre ytorna från en slät, och ett vibrationssinne för att särskilja mellan olika släta strukturer. Friktionen visade sig alltså vara en viktig fysikalisk egenskap för strukturer under åtminstone 10 µm i ytråhet. Från fingerfriktions mätningar kunde även följande slutsatser dras: (i) Stora skillnader i friktionskoefficient mellan olika personer uppmättes, men trenderna mellan olika individer var samma, vilket gör att relativa skillnader i friktion från en individ är representativa. (ii) Lipider (fingerfett) som överförs från fingret till ytan vid kontakt sänker friktionen. (iii) Frekvensinnehållet i friktionskraften varierar mellan olika ytor och den frekvenstopp som ses vid 30 Hz kan möjligtvis bero på fingrets struktur eller resonansfrekvensen på huden. (iv) Den pålagda kraften under en friktionsmätning visar sig omedvetet regleras av den friktionskraft som fingret möter under rörelse. Hur små strukturer som kan diskrimineras har indirekt undersökts genom likhetsförsöket på modellytorna där försökspersoner skulle bedöma hur lika alla par av ytor kändes. Resultaten visade att ytorna med våglängder på 760 nm och 870 nm upplevdes olika jämfört med referens ytor utan något systematiskt mönster, medan ytan med 270 nm i våglängd inte kunde särskiljas. Amplituden på ytan som kunde diskrimineras var endast ca 10 nm, vilket indikerar att nanoteknologi mycket väl kan bidra inom haptiken och för att i framtiden kontrollera den taktila perceptionen.<br><p>QC 20121026</p>
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Watts, John F. "Research papers." Thesis, University of Surrey, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.361803.
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Åvitsland, Grete A. "Edgewise liquid penetration in paper : influence of surface chemistry and paper structure /." Stockholm, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4082.
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Niembro, Martin Alejandro. "Conception et développement de supports imprimables souples pour filtrage et adaptation des ondes électromagnétiques radiofréquences." Thesis, Université Grenoble Alpes (ComUE), 2015. http://www.theses.fr/2015GREAT062.
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Les communications sans fil sont de plus en plus présentes dans notre quotidien, et avec elles, les ondes électromagnétiques qui leurs sont associées. Cela a créé un besoin de produits permettant de contrôler la portée du réseau, pour des raisons de sécurité de données, d'augmentation de débit en cas d'interférences avec d'autres réseaux, ou bien pour des raisons sanitaires. A l'inverse, dans d'autres cas, l'amélioration de la transmission de ces ondes est recherchée. Par exemple, dans les bâtiments de nouvelle construction ou rénovées, l'installation de vitrages à isolation renforcée permet d'avoir des bâtiments plus performantes au niveau thermique. Malheureusement, ces vitrages bloquent également les radiofréquences, dont notamment les signaux de téléphonie mobile. L'objectif de la thèse est la conception et le développement de structures filtrantes imprimées sur substrat souple. Dans un premier temps, des solutions de filtrage sélectif coupe bande sont proposées afin d'empêcher autant que possible la transmission d'ondes électromagnétiques, par exemple celles du WiFi entre les pièces d'un bâtiment. Dans un deuxième temps, une solution permettant d'améliorer la transmission des ondes électromagnétiques au travers des vitrages thermiques est proposée. Outre ces études, un système de caractérisation permettant de caractériser finement ces structures FSS a été développé lors de ces travaux de thèse<br>Nowadays wireless communication systems are more and more present in our lives, and with them, electromagnetic waves associated to them. A need of products capable to control the range of the network has appeared, for data security reasons, for data rate increase in case of network interferences or for health reasons. On the opposite, in other cases, improving the transmission of these waves is desired. For instance, in new construction or renovated buildings, energy saving windows allows having more efficient buildings thermal speaking. Unfortunately, those windows also block radiofrequencies, including mobile phone signals. The aim of this thesis is the design and development of filtering structures printed on flexible substrate. First, stop band selective filtering solutions are proposed in order to block as much as possible transmission waves, for instance, WiFi in between different rooms of the same building. Secondly, a solution to improve electromagnetic wave transmission through energy saving windows is proposed. In addition to these studies, a characterization system for testing these FSS structures has been developed during this thesis work
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Soysouvanh, Davy. "Mesure optique de la topographie des papiers." Grenoble INPG, 2007. http://www.theses.fr/2007INPG0081.
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Plusieurs étapes dans le procédé de fabrication des papiers ont pour objectif d'améliorer l'état de la surface. La raison à cela est que certaines propriétés importantes, telles que le brillant ou la friction, dépendent énormément de la surface, de même que la qualité d'impression. Les méthodes traditionnelles pour caractériser les papiers sont basées sur des écoulements d'air à leur surface. Cependant, celles-ci se révèlent beaucoup trop limitées et ne permettent pas d'accéder à la topographie. Nous avons évaluées plusieurs méthodes optiques de mesure de micro-topographie et nous avons retenue la méthode d'interférométrie en lumière blanche. En travaillant sur l'optique et sur les algorithmes de mesure, nous l'avons adaptée au cas très spécifique des surfaces rugueuses et fortement diffusantes. L'instrument mis au point est aujourd'hui utilisé dans plusieurs applications et sur différents matériaux rencontrés en papeterie, où il permet des mesures simples, précises et rapides<br>Several stages in the manufacturing process of paper aim to improve the surface quality. The reason is that several important properties of paper, such as the brightness or the friction, enormously depend on the surface, just as the quality of the printing. The traditional methods to characterize pa pers are based on flows of air on their surface. However, those appear to be too much limited and do not allow to access the topography. We evaluated severa 1 optical methods of measurement of microtopography and we adopted the full-field method of white light interferometry. While working on the optics and on the algorithms of measurement, we adapted the method to the very specifie case of rough and strongly diffusing surfaces. The instrument that has been developped is used today in several applications and on various materials met in the paper mi Il, where it allows simple measurements, precisely and very rapidly
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Shirazi, Mehdi. "Surface application of yellowing inhibitors into paper." Thesis, McGill University, 2001. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=38281.
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Papermakers are highly interested in upgrading mechanical paper by retarding or inhibiting the lignin color reversion. Yellowing can be prevented by screening UV light on the surface and adding yellowing inhibitors into papers. Surface treatment of paper in a size press by an inhibitor-starch mixture has more advantages compared to other methods. A novel microscopy technique using scanning electron microscopy is developed to identify and measure the polymer penetration into sized sheets.<br>The kinetics of starch adsorption on wood fibers was elucidated. An initial high adsorption of cationic starch on pulp fibers is off set by high desorption rates. Furthermore the adsorption of hydroxyethyl ether starch increases smoothly with time due to polymer penetration into the macropores. At high salt concentrations, cationic starch does not make strong bonds with negatively charged fibers and as a result the desorption rate increases and the maximum adsorption approaches zero. The presence of salt has little effect on the adsorption of non-ionic hydroxyethyl ether starch.<br>Preferential adsorption of amyIose compared to amylopectin on cellulosic fibers is related to the size exclusion mechanism involved in polymer penetration into macropores.<br>The presence of cationic starch clusters is confirmed. The clusters initially adsorb on the fiber surface; however due to a higher desorption rate they are gradually replaced by individual polymers. The cluster size decreases with increasing shear in the presence of salt in cationic starch solutions. The cluster desorption rate for pulp fibers is higher than that for glass substrates. This might be due to different surface chemistry or roughness between pulp fibers and glass substrates. The maximum adsorption on glass substrates increases by increasing the cluster size. Hydroxyethyl ether starch does not form clusters and shear and the presence of salt have a minor effect on the polymer size.<br>Starch pickup by paper during surface sizing depends on the liquid absorption at the puddle and counter pressure of the trapped air in the pores. Starch viscosity, paper velocity and nip load have no effect on the thickness of the starch layer across the sized paper. However, for thick boards penetration increases by increasing the nip load due to lower sheet thickness at higher nip load. For sized board, the starch penetration is less for cationic starch than for hydroxyethyl ether starch due to higher viscosity and adsorption.<br>For the sized sheets with yellowing inhibitor/starch mixtures, the paper brightness after aging is affected by inhibitor concentration in the solution, since operating conditions have little effect on pickup. Using cationic starch slightly increases the brightness for boards, while it has little effect on paper brightness.
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Barros, Fabien de. "Conception, Réalisation et Caractérisation de papiers fonctionnels pour des applications de filtrage électromagnétique." Thesis, Grenoble, 2011. http://www.theses.fr/2011GRENT118/document.
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Le brouillard électromagnétique dans lequel nous vivons en permanence estaujourd’hui montré du doigt car, outre les risques sanitaires qu’il pourrait engendrer, illimite l’usage de certaines technologies. L’importance des interférences entre réseauxsans fil, ou la peur du piratage sur ces mêmes réseaux, en sont deux exemples. Cetravail de thèse vise à développer un nouveau moyen de protection contre certaines deces ondes électromagnétiques. Plus spécifiquement, ce travail se focalise sur unetechnologie capable de filtrer uniquement les ondes WiFi et GSM à travers de grandessurfaces d’une habitation, comme un mur. Pour ce faire, la fonctionnalisation d’uncomposant standard des bâtiments, le papier-peint, a été étudié.L’utilisation de surfaces sélectives en fréquence a été retenue. Ces motifs sontdirectement imprimés sur du papier à l’aide d’encre conductrice et de la techniqued’impression flexographique. L’étude s’est également portée sur la réalisation de motifsde filtrage innovants. Les résultats de simulation montrent qu’ils sont capables de filtrerdeux ou trois bandes, qu’ils sont quasiment insensibles à la polarisation et à l’angled’incidence dans une plage allant de 0° à ± 80°. Le travail a ensuite permis dedémontrer la faisabilité pratique de ce concept aux stades laboratoire et industriel.Ensuite, nous avons démontré expérimentalement l’efficacité de ce concept dans lesbandes WiFi. La transmission atteint alors -30 dB. Enfin, une validation expérimentaledu produit en situation réelle a été menée, à savoir la pose du papier-peint sur du plâtre,du bois, l’influence de la colle ou encore la pose d’une couche de papier-peint décoratifpar-dessus le produit.En conclusion, les résultats pratiques obtenus confirment les résultats théoriquesestimés et, permettent à ce nouveau concept, appelé métapapier, d’être suffisammentefficace pour permettre la réduction des ondes WiFi ou GSM<br>The electromagnetic smog in which we live today is nowadays a real issue because it limits the use of certain technologies and also because there are some potential health risks associated with it, even if the latter is still a controversial subject. The importance of the interferences between wireless networks or the possibility of data hacking on the same networks are two examples. The aim of this thesis is to develop a new way to protect buildings against some of these electromagnetic waves. More specifically, this work focuses on a technology able to filter only the WiFi and the GSM waves through large areas of a home, like a wall for example. To do this, the functionalization of a standard component of buildings, the wallpaper, was studied. The use of frequency selective surface (FSS) was chosen. These patterns are printed directly on paper with a conductive ink printing technology: the flexography. The study also focuses on the realization of innovative filter designs. Simulation results show that these novel FSS are able to filter two or three bands. They are almost insensitive to the polarization and to the angle of incidence in the range of 0° to ±80°. The realization feasibility of this concept in a laboratory or in industrial conditions was demonstrated. Next, an experimental demonstration of this concept in the WiFi bands was carried out. In this context, the transmission coefficient was reached -30 dB. Finally, an experimental validation of the product in real conditions of use was conducted, namely the wallpaper was put over plasterboards or over wood panels. Also, the influence of the glue on the general performances and the placement of a decorative wallpaper over the FSS wallpaper were studied. In conclusion, the practical results obtained confirm and validate the theoretical predictions of this new concept, called metapaper, and show that the practical realizations are efficient enough to allow the reduction of WiFi or GSM signals
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Fidjestøl, Svein. "Effective Quantification of the Paper Surface 3D Structure." Thesis, Norwegian University of Science and Technology, Department of Computer and Information Science, 2005. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-9208.
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<p>This thesis covers the topic of image processing in relation to the segmentation and analysis of pores protruding the surface in the three dimensional surface structure of paper. The successful analysis of pores is related to a greater goal of relating such an analysis to the perceived quality of the surface of a paper sample. The first part of the thesis gives an introduction to the context of image processing in relation to paper research. Also, an overview of the image processing framework used for image processing plugin development, ImageJ, is provided, together with the current status of ImageJ plugins for surface characterization. The second part of the thesis gives an overview of an envisioned future paper quality assessment system. The quality assesment system described consists of six phases, three of which are treated in this thesis. These are the Image Processing phase, the Modeling phase, and the Measurement phase. The Image Processing phase is further divided into three subphases. These are the Error Correction subphase, the Pore Extraction subphase, and the Segmentation phase. Together with the description of the phases of the system, techniques are presented that are relevant to the phase currently being described. The third part of the thesis covers the development of new plugins for surface characterization within the ImageJ framework. Examples are given and evaluated to show the usage and results of each plugin, and each plugin is related to a specific part of the quality assesment system. Also, a tutorial covering use of several plugins in sequence is presented. The parts of the system receiving the most attention in relation to plugin development are segmentation and modeling.</p>
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Delgado, Ezequiel. "The potential of zwitterionic bonding in paper /." Thesis, Connect to this title online; UW restricted, 1994. http://hdl.handle.net/1773/5549.
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Missoum, Karim. "Modification chimique de surface de NanoFibrilles de Cellulose (NFC)." Phd thesis, Université de Grenoble, 2012. http://tel.archives-ouvertes.fr/tel-01072240.
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Les nanocelluloses connaissent un fort développement depuis ces dernières décennies et font l'objet de nombreuses études menées par les industriels et/ou consortiums académiques. Cette étude s'insère dans le cadre d'un projet européen (SUNPAP) visant à l'industrialisation des nanofibrilles de cellulose (NFC). La présente thèse fait l'état de nouveaux procédés de modification chimique de surface des NFC dans une optique de chimie verte. Plusieurs stratégies ont été développées telle que l'emploi de liquides ioniques comme solvant de réaction (décrit comme solvants verts) ou l'utilisation d'une nanoemulsion en phase aqueuse permettant le greffage de surface des NFC. Dans le but d'étudier l'impact de ces modifications chimiques, les substrats ainsi traités ont été par la suite utilisés dans diverses applications. Ainsi, des bionanocomposites ont pu être produits, l'impact sur l'introduction de NFC (modifiées ou non) dans du papier a également été étudié. Une étude sur les propriétés antibactériennes et la biodégradabilité des NFC modifiées est également proposée. Une caractérisation approfondie des NFC vierges et modifiées a été réalisée. Des techniques puissantes et innovantes ont été utilisées pour caractériser ces substrats tels que l'XPS (X-ray Photoelectron Spectroscopy) ou encore la SIMS (Secondary Ion Mass Spectrometry). Toutes ces modifications, applications et caractérisations proposées constituent une avancée et des perspectives prometteuses dans le monde des nanocelluloses.
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Fike, Gregory Michael. "Determination of Polymer Film Development through Surface Characterization Studies." Diss., Georgia Institute of Technology, 2005. http://hdl.handle.net/1853/6879.
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Unexpectedly, it was found that when a waterborne polyacrylate adhesive was placed on carbon steel it was not tacky; this was not the case for the same adhesive placed on stainless steel. It was determined that the surface energy, as measured with liquid contact angles, of the adhesive films is significantly different between the two films, with the non-tacky film having a higher surface energy. Atomic force microscopy (AFM) showed that the non-tacky surface has a higher roughness which minimizes the contacting area between the film and a contacting surface.
Analysis of the heating of the carbon steel coupon with infrared thermography shows a non-uniform temperature profile at the surface. This experimental data is corroborated using a 2-D heat transfer model that incorporates the heat transfer characteristics of the various components of carbon steel. Surface driven flow, or Marangoni convection, can develop from temperature gradients and are known to cause increased roughness in polymer films. IR thermography measurements of the adhesive film during drying shows larger temperature differences for the films on carbon steel than on stainless steel. These larger temperature differences induce greater Marangoni convection, which result in the rougher surfaces on carbon steel that were measured with AFM.
The effect of lowering the tack of a polyacrylate film has significant impact in the dryer section of a paper machine. This effect was quantified using the Web Adhesion Drying Simulator, which is a laboratory-scale apparatus that measures the energy required to pull the sheet from a metal surface. By substituting the adhesive-on-stainless steel with the less-sticky adhesive-on-carbon steel surface, the energy required to pull the sheet from the metal surface was reduced significantly and the picking associated with the test was nearly eliminated.
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McMahon, Jeff. "Modelling coating on the surface of paper for quality assurance." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape3/PQDD_0015/MQ48582.pdf.
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Li, Ruonan. "Surface properties and pore structure of superheated steam dried paper." Thesis, McGill University, 1993. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=55414.
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Effects of superheated steam drying were determined for surface properties and pore structure of paper, properties which are important in the end use of paper. Two furnishes were investigated, thermomechanical pulp (TMP) and a TMP/kraft pulp blend. Drying of handsheets under matched conditions in air was used as the basis of comparison.<br>TMP paper dried in superheated steam has a slightly higher surface roughness, by about 0.5 $ mu$m at a roughness around 8 $ mu$m. This difference decreases with drying fluid temperature. It is also reduced by about half after a very light blade coating. Surface roughness of paper from 50/50 TMP/kraft blend is unaffected.<br>Superheated steam drying reduces substantially the linting propensity of TMP paper, by about 30%-60% depending on the criteria used. Improved lignin softening by higher web temperature from the beginning of drying in superheated steam drying is believed an important mechanism in improving bonding of surface fines and short fibre fragments.<br>The Z-direction bond strength of TMP paper after surface treatment with water is about 20% higher for sheets dried in steam. Time for water absorption is 100%-150% longer for superheated steam dried TMP paper and contact angle of water is also substantially increased.<br>Superheated steam drying substantially reduces the volume of micropores of diameter 0.2-0.6 $ mu$m while having no significant effect on larger pores. Thus superheated steam drying affects only the pore structure of the micronetwork. The decrease of micropore volume in superheated steam drying is associated with an increase of Z-direction bond strength and a decrease of light scattering coefficient.
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PEIXOTO, CLARISSA FERREIRA. "SURFACE CLEANING OF HISTORICAL PAPER DOCUMENTS USING ND: YAG LASER." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2012. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=22327@1.
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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO<br>COORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIOR<br>PROGRAMA DE SUPORTE À PÓS-GRADUAÇÃO DE INSTS. DE ENSINO<br>A conservação e restauração de obras de arte e objetos de interesse histórico se afirma como ciência que agrega várias áreas do conhecimento. O processo de limpeza superficial se impõe como ponto fundamental e crítico em todas as intervenções, pois, tradicionalmente, envolve processos invasivos e de difícil controle. O método de limpeza a laser se coloca como solução viável, e amplamente difundida em intervenções realizadas em mármores e metais. Estudos demonstram a viabilidade na utilização do laser Nd YAG para a limpeza de papel. O suporte a ser tratado é um papel de pasta mecânica, da década de 30, que foi irradiado com feixe de 532nm. Visando a otimização do modo operacional, os parâmetros tempo de exposição, frequência, energia depositada e distância focal foram alterados. A fim de comparação, foi realizado limpeza aquosa para estabelecer a eficiência dos métodos tradicional e à laser. A análise dos resultados foi baseada na avaliação óptica, utilizando o método CIELab, e através da Microscopia Eletrônica de Varredura MEV.<br>Conservation and restoration of artworks and objects of historical interest is a science that combines several areas of knowledge. The surface cleaning step is an essential and critical process in every conservation procedure, because it involves traditionally invasive processes that are hard to control. The laser cleaning method is a viable solution, and in widespread interventions in marble and metal. Studies demonstrate the viability of the use Nd YAG laser for cleaning paper. The support to be treated is a paper of mechanical pulp, from the 30s, by 532nm laser beam. The evaluated parameters were the operational mode, the exposure time, the energy deposited and the focal length parameters. Classical wet method was used for comparison, aqueous cleaning was performed to establish the efficiency of traditional methods and laser. The paper surface was characterized by visual inspection, CIELab method and scanning electron microscopy SEM. Some conditions did clean the surface with minor damage.
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Lemaster, Richard L. "Development of an Optical Profilometer and the Related Advanced Signal Processing Methods for Monitoring Surface Quality of Wood Machining Applications." NCSU, 2004. http://www.lib.ncsu.edu/theses/available/etd-09282004-152158/.
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The research described here provides the technology and theory to quantify surface quality for a variety of wood and wood-based products. This technology provides a means of monitoring trends in surface quality which can be used to discriminate between Agood@ products and Abad@ products (the methods described in this research are not intended to provide ?grading? of individual workpieces) as well as provide information to the machine operator as to the source of poor quality machined surfaces. The analysis can be done either on-line at industrial speeds or off-line as a periodic quality control tool. Although the surface quality can be quantifiably measured, the determination of the best feature from the surface profile (root mean square, peak amplitude, average wavelength, frequency content, Joint Time and Frequency Analysis (JTFA) and Wavelet Analysis results, etc.) for the quantification of surface Adefects@ is highly dependent on the application. This research consisted of three broad areas: (1) determination of an optimal hardware configuration for both laboratory and industrial surface scans of wood products, (2) determination of the optimal set of surface descriptors as well as the development of advanced signal processing techniques such as the wavelet transform to accurately describe the quality of a surface as well as provide information to the machine operator on the cause of the loss of surface quality, and (3) development of a software interface to distill the advanced signal processing techniques into a readily obtainable and readable format for the machine operator as well as provide assistance for process decisions.
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Liu, Eunice. "Do plano à forma." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/16/16134/tde-16022017-103149/.
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Ensaios realizados em papel para investigação e conhecimento de tipologias de forma geradas a partir da bidimensionalidade, construídas por princípios de dobragem, corte e entrelaçamento. Realizado por método experimental criativo, os ensaios foram inspirados, reproduzidos e gerados a partir da observação de florescência e crescimento de plantas, de texturas e princípios têxteis, de cordas e linhas, elementos de padronagem, geometria e desenhos livres, desenvolvidos manualmente, sendo os cortes executados em máquina de corte a laser. A superfície ora é modificada, caracterizando um plano diferente, ora constitui uma unidade modular, desenhada pelo corte, que multiplicada e combinada, deriva outros planos ou formas bi e tridimensionais. A interferência no plano modifica sua visualidade, textura, acústica, e funcionalidades, como flexibilidade, permeabilidade, colapsibilidade, seu comportamento, assim como a percepção e apreensão da forma pelos sentidos. O objetivo da pesquisa é ordenar classes de tipologias formais básicas para compreender leis elementares de construção e comportamento da forma material, cujos princípios geram outras formas mais complexas.<br>Experiments made on paper for research and knowledge of form typologies generated from bidimensionality, created by folding, cutting and interlacement principles. Developed by creative experimental method, the experiments were inspired, reproduced and generated from the observation of plants inflorescence and growth, textures and textiles principles, of ropes and threads, patterning elements, geometry and free drawings, manually produced, being cut on a laser cutting machine. The surface is either modified, featuring a different plan, or constituting a modular unit designed by the shape of the cut, which being multiplied and combined, derives other plans or bi and tridimensional forms. The interference in any plan modifies its visuality, texture, acoustics, and features such as flexibility, permeability, collapsibility, its behavior, as well as the perception and apprehension of the form by the senses. The objective of the research is to order classes of basic typologies of form to understand basic laws of construction and behavior of the material form, which principles generate more complex forms.
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Gay-Bellile, Vincent. "Contributions au recalage et à la reconstruction 3D de surfaces déformables." Phd thesis, Université Blaise Pascal - Clermont-Ferrand II, 2008. http://tel.archives-ouvertes.fr/tel-00731045.
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Cette thèse porte sur le développement d'outils permettant le recalage d'images d'une surface déformable et la reconstruction tridimensionnelle de surfaces déformables à partir d'images prises par une seule caméra. Les surfaces que nous souhaitons traiter sont typiquement un visage ou une feuille de papier. Ces problématiques sont mal posées lorsque seule l'information présente dans les images est exploitée. Des informations a priori sur les déformations physiquement admissibles de la surface observée doivent être définies. Elles diffèrent en fonction du problème étudié. Par exemple, pour une feuille de papier, la courbure Gaussienne évaluée en chacun de ces points est nulle, cette propriété n'est pas valide pour un visage. Les applications visées sont l'insertion réaliste de logo 2D, de texte et aussi d'objets virtuels 3D dans des vidéos présentant une surface déformable. La première partie de cette thèse est consacrée au recalage d'images par modèles déformables. Après avoir brièvement introduit les notions de base sur les fonctions de déformation et sur leur estimation à partir de données images, nous donnons deux contributions. La première est un algorithme de recalage d'images d'une surface déformable, qui est efficace en terme de temps de calcul. Nous proposons une paramétrisation par primitives des fonctions de déformation permettant alors leur estimation par des algorithmes compositionnels habituellement réservés aux transformations formant un groupe. La deuxième contribution est la modélisation explicite des auto-occultations, en imposant la contraction de la fonction de déformation le long de la frontière d'auto-occultation. La deuxième partie de cette thèse aborde le problème de la reconstruction tridimensionnelle monoculaire de surfaces déformables. Nous nous basons sur le modèle de faible rang : les déformations sont approximées par une combinaison linéaire de modes de déformation inconnus. Nous supposons que ces derniers sont ordonnés par importance en terme d'amplitude de déformation capturée dans les images. Il en résulte une estimation hiérarchique des modes, facilitant l'emploi d'un modèle de caméra perspectif, la sélection automatique du nombre de modes et réduisant certaines ambiguïtés inhérentes au modèle. Nous explorons finalement la capture des déformations d'une surface peu texturée à partir de données issues d'un capteur 3D. L'information présente au niveau des contours de la surface est notamment utilisée. Nous avons implanté les différentes contributions décrites ci-dessous. Elles sont testées et comparées à l'état de l'art sur des données réelles et synthétiques. Les résultats sont présentés tout au long du tapuscrit.
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Jain, Ishan. "Paper-Based Sensors for Contaminant Detection Using Surface Enhanced Raman Spectroscopy." Thesis, Virginia Tech, 2015. http://hdl.handle.net/10919/53946.
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Surface enhanced Raman spectroscopy (SERS) is highly promising analytical technique for trace detection of analytes. It is particularly well suited for environmental analyses due to its high sensitivity, specificity, ease of operation and rapidity. The detection and characterization of environmental contaminants, using SERS is highly related to the uniformity, activity and reproducibility of the SERS substrate.
In this thesis, SERS substrates were produced by gold nanoparticle formation on wax patterned chromatography paper. In situ reduction of hydrogen tetrachloroaurate (gold precursor) by trisodium citrate dihydrate (reducing agent) was used to produce gold nanoparticles within a paper matrix. These gold nanoparticle based SERS substrates were analyzed by FE-SEM, UV-Vis and Raman spectroscopy. This work discusses the SERS signal enhancements for Raman active MGITC dye for a series of substrates prepared by in situ reduction of gold salt and pre-produced gold nanoparticles. UV-Vis analysis was performed to understand the effect of different molar ratio (reducing agent to gold precursor) and reaction time on the size and shape of the localized surface plasmon resonance (LSPR) band that dictates the SERS enhancements. It was concluded that lower molar ratio (1:1 and 2:1) of citrate-to gold produced better SERS signal enhancements and broader LSPR band. Therefore, use of lower molar ratio (MR) was recommended for paper-based substrates using in situ-based reduction approach.<br>Master of Science
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Mangin, Patrice J. "Etude de la destructuration de la surface du papier en zone d'impression offset." Grenoble INPG, 1988. http://www.theses.fr/1988INPG0099.
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On propose un modele de destructuration de la surface du papier en zone d'impression. On implique le phenomene de decohesion d'une particule fibreuse par l'interaction entre les forces de tirant des encres et les forces de cisaillement. On decrit les formes des courbes de destructuration en fonction de la charge d'encre sur la plaque d'impression et on definit quatre zones de destructuration en fonction de l'importance relative des forces de decohesion. On explique les effets de la vitesse, de la pression d'impression, de la viscosite des encres, des proprietes de contexture et de la composition en pates du papier sur la destructuration en fonction d'une synergie entre ces parametres et du degre de saturation en encre de la structure poreuse. Pour ce faire, on developpe un modele decrivant la rugosite lors de l'impression. On realise un essai de peluchage sur presse offset pilote et on etudie l'accumulation des peluches sur le blanchet
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Serles, Andrew. "An experimental study of the surface distribution of filler material in paper." Thesis, University of British Columbia, 2012. http://hdl.handle.net/2429/43379.
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A series of experiments were conducted to observe the effect of different pulp suspension and formation characteristics on the variation in filler concentration on the surface of paper. Hand sheet samples were formed in a laboratory apparatus. The surface distribution of two types of filler material was investigated: Precipitated Calcium Carbonate (CaCO₃) and Kaolin Clay (Al₂Si₂O₅(OH)₄). The effect of retention aids, dewatering rate, and forming fabric geometry on filler distribution was tested.
The analysis was focused on the variation in surface filler concentrations on the scale of individual strands of the forming fabric. The procedure involved locating areas of interest in the samples, particularly the area of paper formed over knuckles, threads, and openings in the fabric, at which point the sample was analysed with Energy Dispersive X-Ray Spectroscopy and image analysis techniques to determine relative filler concentrations.
In samples formed by gravity and vacuum drainage, Kaolin displayed a significantly greater variation in local surface filler concentration than PCC, though the difference was reduced under vacuum drainage conditions. This effect is attributed to the electrostatic attraction between PCC and pulp fibres in contrast with the repulsion felt by Kaolin filler. The attraction resists the distributing forces of the flow at low drainage velocities but the bonds are broken by large shear forces. The distribution on the top side of the paper was comparable between the filler types, due to the more uniform flow field at a distance from the forming fabric. Vacuum drainage increased the spatial variation of both fillers by a similar amount.
It was found that under vacuum drainage, retention aids did not improve filler uniformity on the wire side. However, on the top side of the paper, a moderate reduction in spatial variation was observed. Additionally, on the wire side of samples made with gravity drainage, it was found that the addition of retention aids produced a significant improvement in the uniformity of the filler material. Finally, it was found that a finer forming fabric improved the uniformity of filler distribution.
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Mangiante, Gino. ""Green" and innovative chemical modifications of cellulose fibers." Thesis, Lyon, INSA, 2013. http://www.theses.fr/2013ISAL0024.
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Ce projet de recherche mené en collaboration avec le CTP (Centre Technique du papier) a eu comme objectif de mettre en place une stratégie de greffage de polymères sur des fibres de cellulose via « Chimie Click » dans l’eau et dans des conditions douces et respectueuses de l’environnement afin de conférer de nouvelles propriétés mécaniques aux papiers résultants. La première étape a été d’élaborer une fonctionnalisation alcyne des fibres dans des conditions douces – dans l’eau ou dans un mélange eau/isopropanol – permettant à la fois une fonctionnalisation conséquente tout en préservant la cristallinité de la cellulose, la structure fibre et les propriétés mécaniques. Différentes méthodes de microscopie ont été utilisées pour mieux comprendre l’impact de la fonctionnalisation sur les propriétés mécaniques. Afin d’améliorer les propriétés mécaniques du papier, le greffage sur les fibres de polyéthers d’alkyle fonctionnalisés azoture a été réalisé dans l’eau par cycloaddition de Huisgen d’azoture-alcyne catalysée par le cuivre (II) (CuAAC). Plusieurs polymères de natures différentes (poly(éthylène glycol) et poly[(éthylène glycol)-stat-(propylène glycol)]), de différentes masses molaires et fonctionnalités (mono- ou difonctionnels) ont été liés aux fibres de cellulose. L’ajout de chaînes de poly(éthylène glycol) s’est avéré avoir un effet lubrifiant entraînant une légère diminution de l’indice de traction mais une augmentation importante de la flexibilité du papier. De plus, le greffage de polymères difonctionnels a démontré des propriétés originales de résistance à l’eau sans changer la nature hydrophile des fibres de cellulose. Enfin, le couplage Thiol-Yne a permis de fixer de petites molécules hydrosolubles fonctionnalisées thiol sur des fibres modifiées alcyne en s’affranchissant du cuivre nécessaire à la réalisation de la réaction de CuAAC<br>This research project, in collaboration with CTP (Centre Technique du Papier), aimed at developing chemical pathway in water to graft polymers on cellulose fibers via “Click Chemistry” in eco-friendly and non-degrading conditions conferring new mechanical properties upon the resulting paper sheets. A first step was to develop a “green” alkyne derivatization method in mild conditions – through pure water or water/isopropanol mixture – allowing for a substantial alkyne functionalization without jeopardizing the cellulose crystallinity, the fiber structure, and maintaining good mechanical properties of the cellulose fibers and resulting paper sheets. To better understand how the functionalization impacts the mechanical properties, several microscopy methods were employed. Then, aiming at improving mechanical properties of the resulting paper, grafting of azidefunctionalized polyoxyalkylenes on alkyne-modified fibers was achieved via Copper(II)-Catalyzed Alkyne-Azide Cycloaddition (CuAAC) in pure water. Water soluble polymers of different nature (poly(ethylene glycol) or poly[(ethylene glycol)-stat-(propylene glycol)]), with different molar mass and functionality (one or two azide groups per macromolecular chain) were successfully attached on cellulose fibers. Grafting of PEG chains involved a slight decrease of the tensile index but a drastic increase of the flexibility of the paper sheet. Interestingly, fibers grafted with difunctional polymers demonstrated an original water resistance maintaining the hydrophilic nature of fibers. Finally, Thiol-Yne reaction was successfully carried out to attach small water soluble thiol-bearing reagents on alkyne-functionalized fibers in water as a metal-free alternative to CuAAC reaction
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Santos, Andrea de Sousa. "Le rôle des tensioactifs dans la flottation des encres offset lors du désencrage des fibres cellulosiques." Grenoble INPG, 1997. http://www.theses.fr/1997INPG0041.
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Pour desencrer des vieux papiers, les papetiers utilisent actuellement des savons ou des tensioactifs pour mieux eliminer les particules d'encre a la flottation. Cependant, les mecanismes physico-chimiques responsables de la flottation ne sont pas encore tres bien compris. Ce travail de these met en evidence l'influence des differentes natures de tensioactifs sur le desencrage par flottation. Il a ete observe que le tensioactif utilise lors de la desintegration d'une composition de 100% journaux offset influence fortement la fragmentation et le decrochage de l'encre. Le niveau de fragmentation de l'encre a l'entree de la flottation est primordial quant a la blancheur finale de la pate. Toutefois, les resultats montrent que certaines proprietes des tensioactifs telles que la cmc et la hlb n'ont pas d'influence significative sur la desintegration ni l'elimination de l'encre. Des etudes sur la caracterisation des surfaces d'encre offset montrent que la nature de l'huile (vegetale ou minerale) utilisee dans la fabrication de l'encre joue un role tres important sur l'adsorption des tensioactifs sur les particules d'encre. Les essais de chromatographie gazeuse en phase inverse ont permis de montrer que certains tensioactifs modifient fortement l'energie de surface des particules d'encre. Les mesures de l'adsorption de savon et de tensioactif sur l'encre et les fibres montrent que l'adsorption du savon sur les fibres est tres elevee. Sur l'encre, elle depend fortement du savon ou du tensioactif utilise.
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Jonhed, Anna. "Properties of modified starches and their use in the surface treatment of paper." Doctoral thesis, Karlstad University, Faculty of Technology and Science, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-735.
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<p>The papermaking industry uses a large amount of starch each year, both as a wet-end additive and as a rheological modifier in surface sizing and coating colors. It is important to be able to reduce the amount of chemicals used in the papermaking and surface treatment process, to reduce costs and to make the process even more efficient. Interest in new high-performance starches is great. By using these new types of starches, improved recycling of barrier products may be obtained as well as a reduction in the use of synthetic sizing agents. The objectives of this work were to understand the behavior of temperature-responsive hydrophobically modified starches, where the solubility in water simply can be adjusted by temperature or by polymer charge, to improve the barrier properties, like the water vapor permeability, mechanical properties and water resistance (Cobb and contact angle) of papers surface sized by starch-containing solutions, and to investigate the potential for industrial use of these temperature-responsive starches. It was demonstrated that the temperature-responsive starches phase separate upon cooling and, depending on the charge density of the starch, a particulate precipitation or a gel-like structure was obtained. The starch with zero net charge showed a larger increase in turbidity than the starch with a cationic net charge, indicating that particulate precipitation is favored by a zero net charge and that the formation of a gel network is favored by charged starch molecules. Further, the starches formed inclusion complexes with surfactants, giving stabilization to the starches in the presence of surfactants. The net charge density of the starch and the charge of the surfactant determined whether or not an inclusion complex would form between them. Important mechanisms for the stability of the starch seemed to be formation of mixed micellar-like structures between the hydrophobic chain of the starch and the surfactant along the starch backbone in addition to formation of inclusion complexes between the starch and the surfactant. The hydrophobically modified starches showed higher hydrophobic surface character when applied to the paper surface above the critical phase separation temperature than with application at room temperature. Free films of the temperature-responsive starches showed good barrier against oxygen, but no barrier against water vapor. The mechanical properties decreased with addition of glycerol to the films.</p>
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Holmqvist, Johan. "Development of Free-Standing Interference Films for Paper and Packaging Applications." Thesis, Linköping University, The Department of Physics, Chemistry and Biology, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-11398.
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<p>The newfound capability of creating moisture sensitive interference multilayered thin films (MLTFs) comprising microfibrillated cellulose and polymers has not previously been possible to implement on surfaces other than silicon wafer strips. Being able to incorporate interference MLTFs on fibre-based materials would introduce the possibility for new applications within authentication, sensing and customer attraction for the paper and packaging industry. By using trichloro (1H, 1H, 2H, 2H-perfluorooctyl) silane we were able to hydrophobically modify silicon substrates, enabling interference MLTF lift-off and thus the creation of free-standing MLTFs of approximately 400 nm thickness. Contact dried MLTFs approximately 250 nm thick, were successfully transferred to copy- and filter paper as well as to cellulose-based dialysis membranes. We can also report on the successful synthesis of interference MLTFs directly on a fibre composite material and on aluminium. Initial tests of a method to quantify the pull-off conditions of the MLTFs from the fluorinated surfaces using the Micro Adhesion Measurement Apparatus showed promising results.</p>
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Huang, Chengsi. "Identification and Validation of Protein Biomarkers for Invasive Aspergillosis; Development of Surface-Induced Dissociation Device and Paper Spray Ionization Source for Protein Complex Studies." Diss., The University of Arizona, 2014. http://hdl.handle.net/10150/347142.
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The research described in this dissertation is divided into two sections. The first section focuses on mass spectrometry-based bottom-up proteomics application to identify fungal protein biomarkers of invasive aspergillosis infection. The second part focuses on instrument development to improve current ionization and dissociation technologies for characterizing topology and substructure of protein complexes. Part I of this dissertation describes the identification and validation of protein biomarkers for Invasive Aspergillosis (IA), a fatal pulmonary infection. Aspergillus fumigatus, the organism responsible for this disease, is an opportunistic fungus. Immunocompromised individuals can suffer from IA due to impaired immune response. The current diagnostic tools are time-consuming and have variable sensitivity and specificity. Hence, treatments for IA are often administered too late. The goal of this research is to use mass spectrometry to identify and validate novel fungal protein biomarkers for IA. To tackle this challenge, several systems were studied. Commercial Aspergillus antigen was used for method development, and to serve as standards for spiking and comparison. Mouse models of different disease manifestations were used in the initial study to compare proteomic differences in carefully controlled disease states. Although it was not successful in providing candidate biomarkers, the mouse samples provided host response protein data. Human patient samples yielded the most promising results. Several Aspergillus proteins have been identified and validated from patient bronchoalveolar lavage fluid, and could have the potential to be later used on a diagnostic platform. Part II describes two instrument development projects: incorporation of a surface-induced dissociation device into a commercial ion mobility time-of-flight mass spectrometer, and the development of a paper spray ionization source. Protein complexes are often studied using collision-induced dissociation (CID), which does not provide enough substructure information. Surface-induced dissociation (SID) allows access to higher energy fragmentation pathways, which generates more useful substructure information. Its potential is demonstrated with three systems here-- one metal cluster and two protein complexes. All systems show that SID can provide more useful structural information than CID under similar conditions. The development of a paper spray (PS) source for protein complex ionization provides another way to study protein complexes. Chapter 9 shows that this ionization method can also be applied to protein complexes. Under the same conditions as its nanospray counterpart, similar mass spectra can be obtained using PS. This exciting result is the first demonstrations that PS can be used for protein complexes while maintaining each protein complex's native structure and conformation.
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Hoč, Miroslav. "Dynamic characterisation of fibre rising on a paper surface after dampening and drying /." Stockholm, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-379.
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Ward, Jennifer Guerin. "Nitrocellulose Paper Based Microfluidic Platform Development and Surface Functionalization with Anti-IgE Aptamers." DigitalCommons@CalPoly, 2012. https://digitalcommons.calpoly.edu/theses/746.
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The purpose of this thesis project was to demonstrate the ability to utilize the capabilities of aptamers so that they may act as capture reagents for paper microfluidic devices. Several characterization experiments were conducted as a precursor before the final experimentation was performed. Paper characterization, manufacturing protocols for printing and heating, as well as 3D chip fabrication were all performed and analyzed. The results confirmed that the control of fluid through a 3D microfluidic device based in nitrocellulose is possible.
For the biochemistry portion of this thesis report, antibodies and aptamers were chosen to react with IgE, an antibody that is present in high concentrations in the urine of patients diagnosed with respiratory distress. Antibody chips were successfully created as a baseline lateral flow assay for comparison to new aptamer detector reagents. The aptamer experiments were able to demonstrate that it is possible to utilize the capabilities of aptamers so that they may behave as capture reagents in paper microfluidic devices. Overall, the experiments performed were extremely supportive of the ability to develop the field of paper microfluidics with the use of aptamers so that patient populations across the globe can be more accurately and effectively diagnosed.