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1
Gehrke, Maik. "Funktionalisierung von Polystyren-Divinylbenzen-Harzen zur selektiven Festphasenextraktion von Aromastoffen." [S.l. : s.n.], 2000. http://deposit.ddb.de/cgi-bin/dokserv?idn=959276637.
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Šálek, Petr. "Příprava a charakterizace magnetických nosičů z hypersíťovaných polystyrenových mikročástic a jejich použití v biosenzoru." Doctoral thesis, Vysoké učení technické v Brně. Fakulta chemická, 2012. http://www.nusl.cz/ntk/nusl-233348.
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With the aim to develop and characterize a functionalized highly magnetic polymer carrier of micrometer size and of a narrow particle size distribution that will be suitable for biological application, hypercrosslinked microspheres were prepared. Simultaneously, the relation between structure and properties of product was observed. Condition of dispersion polymerization were optimized to obtain starting monodisperse poly(styrene-co-divinylbenzene) [P(St-DVB)] microspheres. The P(St-DVB) microspheres of different degree of crosslinking were prepared and effect of some polymerization parameters such as type of solvent, initiator, concentration and mode of DVB addition on morphology, size and particle size distribution were investigated. The starting microspheres were hypercrosslinked to obtain microporous inner structure. Hyperosslinked particles had very large specific surface area (> 1000 m2/g) and a high content of micropores (ca. 0.6 ml/g). First, P(St-DVB) microspheres were chloromethylated using three different chloromethylation agents to regulate their porous properties. Hypercrosslinking was achieved by the addition of stannic chloride as a catalyst and by increasing a temperature. The hypercrosslinked microspheres were then functionalized with sulfo- or aminogroups. The functional groups captured precipitated iron oxide inside the porous structure of the microspheres and also served as a reactive site for intended immobilization of the protein. A solution of ferrous and ferric chloride was imbibed under vacuum into the porous structure and the iron oxide was precipitated by an aqueous ammonia solution. Finally, the magnetic functionalized hypercrosslinked micropsheres were integrated into a biosensor for qualitative detection of ovalbumin.
3
Alger, Luke. "Dispersion polymerisation of divinylbenzene." Thesis, Loughborough University, 2004. https://dspace.lboro.ac.uk/2134/34134.
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Particles containing 55% divinylbenzene (DVB) have been prepared using dispersion polymerisation. The steric stabilisers that have been utilised are partially hydrolysed poly(vinyl acetate)s, poly(ethylene oxide) and a poly(ethylene oxide) macromonomer in methanolic media. The concentrations of stabiliser, monomer and initiator have been varied to investigate the influence that they have on the particle size and the particle size distribution. The particles have been characterised by scanning electron microscopy (SEM) for a visual impression of the particles in addition to laser diffraction particle size analysis and hydrodynamic chromatography (HDC) for particle size.
4
Füssler, Rainer. "Ausschluss- und ionenchromatographische Untersuchungen zur Porenstruktur von PS-DVB-Copolymeren als Trägermaterial für die Ionenchromatographie." [S.l. : s.n.], 2001. http://deposit.ddb.de/cgi-bin/dokserv?idn=963203339.
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Narwark, Oliver. "Spektroskopische Charakterisierung und Bestimmung der Morphologie von substituierten 1,4-Divinylbenzol-Oligomeren." [S.l. : s.n.], 2002. http://deposit.ddb.de/cgi-bin/dokserv?idn=965366758.
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Fleming, James S. "d'8-metal complexes of 1,8-divinylnaphthalene and 1,2-divinylbenzene." Thesis, University of Bristol, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.385969.
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7
Abdallah, Wisam. "Production And Characterization Of Activated Carbon From Sulphonated Styrene Divinylbenzene Copolymer." Master's thesis, METU, 2004. http://etd.lib.metu.edu.tr/upload/12605498/index.pdf.
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Activated Carbon was produced from strong cation-exchange resins, sulphonated styrene divinylbenzene copolymers originally in H+ form, by means of carbonization and steam activation in an electrical furnace. One macroporous resin produced by BAYER Chemicals Inc., Lewatit MonoPlus SP 112 H, was used in the research. Products of carbonization and activation were characterized by using BET, Mercury Porosimetry, Helium Pycnometry and SEM techniques. The effect of carbonization time and temperature on the BET surface areas of the resins were also investigated.
Two sets of carbonization experiments (Set 1 and 2) were performed in which time and temperature were varied in order to study their effects on the BET surface areas of the products. In activation experiments (Set 3), carbonized ion-exchangers (600 oC, 1 hr) were activated with steam at 900°C, changing the time of activation and the steam flow rate. The temperatures of the water bath used for steam generation were selected as 60°
C, 80°
C and 90°
C. The pore structures of activated carbons were determined by proper techniques. The volume and area of macropores in the pore diameter range of 8180-50 nm were determined by mercury intrusion porosimetry. Mesopore (in the range of 50-2 nm) areas and volumes were determined by N2 gas adsorption technique at -195.6oC, BET surface areas of the samples were also determined, in the relative pressure range of 0.05 to 0.02, by the same technique. The pore volume and the area of the micropores with diameters less than 2 nm were determined by CO2 adsorption measurements at 0oC by the application of Dubinin Radushkevich equation. In the experiments of Sets 1 and 2, the BET surface area results of the six different carbonization times ranging from 0.5 to 3 hours gave almost the same value with a maximum deviation of 5% from the average showing almost no effect on the areas of the products. In the experiments of Set 3 , the sample activated at 800°
C for 6 hrs had the highest BET area, 2130 m2/g, and the one activated at 800°
C for 1 hr had the lowest BET area 636 m2/g. N2 adsorption/ desorption isotherms showed no distinct hysteresis indicating a cylindrical geometry of the pores. Adsorption isotherms further indicated that the pores are both highly microporous and mesoporous. N2 (BET) and CO2 (D-R) surface areas of the samples were in the range of 636-2130m2/g and 853-1858 m2/g, respectively. Surface areas of the samples consisted of about 8-53% mesopores and 47-92% micropores.
8
Hubbard, K. Lise (Kirsten Lise-Lotte). "The study of poly(Divinylbenzene-co-ethylvinylbenzene) and modifications to the pendant vinylbenzene groups /." Thesis, McGill University, 1997. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=34644.
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Cross-linked resins of poly(divinylbenzene-co-ethylvinylbenzene) were characterized and modified by a variety of reactions with the pendant vinylbenzene groups. Laboratory-prepared resins of a known composition were compared and contrasted to a commercial version with regard to surface area, porosity, and vinylbenzene content. The commercial resin, Amberlite XAD-4 (Rohm and Haas Company), had a higher surface area (831 m2 /g), porosity (1.18 mL/g), and accessible vinylbenzene groups (2.5 mmol/g, degree of functionalization 33%). Modifications of both resins by radical addition of a variety of thiols led to higher conversions (of vinylbenzene groups to modified groups) with use of the commercial resin (as high as 76%). Further modifications were done strictly with XAD-4. Some thiol additions to XAD-4 were done with water as the solvent, with conversions as high as 43%. Disulfides were added across the vinylbenzene groups of XAD-4 with iodine catalysis, with conversions as high as 55%. This simple one-step reaction has never been done with a polymer system before. XAD-4 was completely epoxidized using a solution of dimethyldioxirane in acetone, and completely brominated to form a resin with (1,2-dibromoethyl)benzene groups (3.76 mmol Br/g). Resins with (1-hydroxy-2-bromoethyl)benzene groups (1.5 mmol/g) were prepared by reaction of XAD-4 with N-bromosuccinimide and water, with 73% conversion. Resins with thiol groups (2.5 mmol S/g) were prepared by a one-pot reaction of brominated XAD-4 with N,N-dimethylthioformamide followed by methanolysis. From one commercially-available resin, several polymers with a variety of functional groups have thus been prepared by simple one- to three-step modifications.
9
Downey, Jeffrey S. "Precipitation polymerization of divinylbenzene to monodisperse microspheres : an investigation of the particle formation mechanism /." *McMaster only, 2000.
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10
Hubbard, K. Lise. "The study of poly(Divinylbenzene-co-Ethylvinylbenzene) and modifications to the pendant vinylbenzene groups." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape16/PQDD_0013/NQ36984.pdf.
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Vivaldo-Lima, Eduardo. "Development of an effective model for particle size distribution in suspension copolymerization of styrene/divinylbenzene." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape11/PQDD_0005/NQ42885.pdf.
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12
Mantha, Madhavi. "Polystyrene as a Medium in Reverse-Phase Separation Of Polycyclic Aromatic Hydrocarbons." Wright State University / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=wright1213730320.
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13
Dempster, Nicola M. "Synthetic modification and characterisation of poly(styrene-co-divinylbenzene) resins and their possible application in environmental analysis." Thesis, Liverpool John Moores University, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.590096.
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Chromatographic micro-beads of the hypercrosslinked poly(styrene-co-divinylbenzene) (PS-OV8) chromatographic adsorbent Amberchrom CG161m, were modified by introduction of polar functional groups using Friedel-Crafts acylation and Bronsted-Lowry nitrating reactions. The Amberchrom CG161m™ microbeads were functionalised by attachment of acetyl, chloroacetyl, dichloroacetyJ, methoxyacetyl, bromoacetyl, nitro and amino groups. Introduction of polar moieties enhances the etridency of the solid phase extraction (SPE) resins by improving surface contact with aqueous samples, increasing capacity and extraction of polar compounds and facilitating greater recovery of strongly held hydrophobic contaminants due to the hydrophilic-lipophilic balance of the adsorbent surface. Fourier-transform infrared spectroscopy (FT-IR), micro-elemental analysis (CHN), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), x-ray fluorescence (XRF), scanning electron microscopy (SEM) and nitrogen adsorption analyses (BET/BJI-I/DFT) were used to characterise the physico-chemical parameters of the novel functionalised resins and confirm success of the chemical reactions. The pristine Amberchrom microbeads, chemically modified PS-DVB adsorbents and bulk commercial resins (Biotage 1ST Env+TM , 1ST C18 EC and Waters Oasis HLB) were packed into analytical columns and solute-sorbent interactions evaluated from retention parameters of interrogative analytes using HPLC. Differences in physical and chemical characteristics of the SPE packing materials were identified and their influences on solute retention parameters and capacities assessed. An objective assessment of solute retention mechanisms on funclionalised sorbents was conducted in sifica using data reduction techniques and chemometric models from HPLC evaluation of solutes based on substituted benzenes. Data reduction techniques included Genetic Factor Approximation (GFA), Principal Component Analysis (PCA) and Factor Analysis (FA), with quantitative structure retention relationships (QSRR) and stepwise multi-linear regression analysis (Stepwise-MLRA) employed for computational modelling. The chemometric elucidation of sorption and elution mechanisms provided further insight into the chromatographic system and clarified perspectives and benefits of the polar functionalised resins and their potential as SPE resins. Chloroacetylated, dichloroacetyJated and methoxyacetylated PS-OVB resins were identified as adsorbents with favourable characteristics for extraction of polar analytes. Chloroacetylated and dichloroacetylated-PS-OVB sorbents also demonstrated a chemical flexibility that could be manipulated to enable mixed-mode retention for multi-residue extraction methods
14
Martinez, Ernesto S. B. Massachusetts Institute of Technology. "Copolymerization of divinylbenzene and 4-vinylpyridine using initiated chemical vapor deposition for surface modification and its applications." Thesis, Massachusetts Institute of Technology, 2013. http://hdl.handle.net/1721.1/81141.
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Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2013."June 2013." Cataloged from PDF version of thesis.
Includes bibliographical references (p. 29-30).
This research investigates the copolymerization of divinylbenzene and 4- vinylpyridine into organic thin films that exhibit conformal, stable, and uniform surface properties. Thin films were grown using initiated chemical vapor deposition, a variant of hot-wire deposition using a chemical initiator. Readily variable monomer flow into the active stage of the reactor allows for directly tunable copolymer composition. This tunability extends onto the control of material surface properties of a substrate that is coated with these organic thin films. The conditions of iCVD allow a variety of delicate substrates to be coated and for the full retention of pendant functional groups. This leads to their application to many industries including water desalination membranes, microfluidics, photolithography, sensors, among many others. The focus of this paper is on the facilitated control of surface modification using iCVD techniques and some of its future applications are also discussed.
by Ernesto Martinez.
S.B.
15
Aguiar, Leandro Gonçalves de. "Síntese de copolímeros de estireno-divinilbenzeno por polimerização radicalar convencional e mediada por nitróxido: experimentos e modelagem matemática." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/3/3137/tde-30072013-235521/.
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Foram realizados experimentos de homopolimerização de estireno e copolimerização de estireno-divinilbenzeno em solução e suspensão aquosa pelos métodos convencional (FRP) e mediado por nitróxido (NMRP). Objetivou-se atingir um maior grau de entendimento sobre estes sistemas em relação ao que se tem na literatura. Para isto, três modelos matemáticos foram avaliados através de validação com os dados obtidos nos experimentos. Os experimentos foram conduzidos em reator de batelada isotérmico. As principais variáveis exploradas neste trabalho foram: temperatura de reação, concentração inicial de divinilbenzeno, diluição inicial da mistura de monômeros e técnicas de polimerização (FRP e NMRP). Os modelos matemáticos foram intitulados: Modelo A, Modelo B e Modelo C. O Modelo A consiste de um balanço de espécies não poliméricas e grupos poliméricos. A determinação das massas moleculares médias e da fração de gel foi feita através de balanços populacionais em termos de função geradora em conjunto com o método das características. Os modelos B e C consistiram de balanços de massa para espécies não poliméricas e método dos momentos para radicais ativos, radicais dormentes e polímero morto. A obtenção das massas moleculares médias e da fração de gel foi feita através do método do fracionamento numérico. Nestes dois modelos, foram consideradas as reações de ciclização através do método dos caminhos. Este método consiste num balanço de segmentos de cadeia que conectam grupos poliméricos. O número máximo de unidades monoméricas, considerado para estes segmentos foi 100 e o valor da constante cinética de ciclização do menor segmento ciclizável (3 unidades monoméricas) foi 450 s-1 para a temperatura de 90°C. O Modelo C leva em conta a redução da reatividade das ligações cruzadas em função do tamanho médio das cadeias em cada geração. Os resultados mostraram que, quando comparado com a FRP, a polimerização NMRP permite somente um controle limitado sobre o processo de reticulação, produzindo distribuições largas de tamanhos de cadeia. Micro e nanoestruturas foram identificadas em produtos obtidos por FRP e NMRP lineares e não lineares. Estas estruturas parecem ser consequência do processo de síntese (ex.: operação em temperatura de reação acima da temperatura de transição vítrea) e do tratamento dos produtos. Massa molecular média mássica e fração de gel foram afetadas consideravelmente pelas reações de ciclização em copolimerizações FRP, porém apresentaram pouca sensibilidade a estas reações em copolimerizações NMRP. A inclusão do mecanismo de ciclização, por si só (no Modelo B), não foi suficiente para produzir bons ajustes modelo/experimentos em termos de massa molecular média mássica (Mw) e fração de gel (Wg). No entanto, o Modelo C é capaz de fornecer boas previsões de Mw e Wg simultaneamente para os experimentos realizados a 90°C. O presente estudo mostrou uma análise na qual os modelos podem se complementar e fornecer subsídios para o desenvolvimento de um modelo unificado.Homopolymerizations of styrene and copolymerizations of styrene-divinylbenzene were carried out in solution and aqueous suspension through conventional (FRP) and nitroxide-mediated (NMRP) techniques. The aim of the work was to reach a higher level of understanding in comparison to what is found in literature. In order to reach this goal, three mathematical models were assessed through validation using experimental data. The experiments were conducted in isothermal batch reactor. The main variables explored in this work were: reaction temperature, divinylbenzene initial concentration, initial dilution of monomers and polymerization techniques (FRP and NMRP). The mathematical models were named: Model A, Model B and Model C. The Model A consists of a balance of non-polymeric species and polymer groups. The average molecular weights and gel fraction were calculated through population balances in terms of generation function together with the method of characteristics. The models B and C were built using mass balance for non-polymeric species and the method of moments for active radicals, dormant radicals and dead polymer. The average molecular weights and gel fraction were calculated through the numerical fractionation technique. In these two models, cyclization reactions were considered through the method of paths. This method consists of a balance of chain segments which connect polymer groups. The maximum number of monomeric units considered for these segments was 100 and the value of the kinetic constant of cyclization for the smaller cyclizable path (3 monomeric units) was 450 s-1 at 90°C. The Model C takes into account the reduction of reactivity of the crosslink reactions in function of the average size of the chains in each generation. The results showed that, when compared with FRP, NMRP allows only a limited control over the crosslinking process, producing broad chain length distributions. Micro and nanostructures were identified in products obtained by linear and non-linear FRP and NMRP. These structures seem to be consequence of the synthesis process (e.g.: operation in reaction temperatures above the glass transition temperature) and of the products treatment. Weight average molecular weight and gel fraction were affected considerably by the cyclization reactions in FRP, however they presented few sensibility to these reactions in NMRP. The inclusion of the mechanism of cyclization, itself (in Model B), was not enough to obtain good model/experiments fittings in terms of weight average molecular weight (Mw) and weight fraction of gel (Wg). Although, the Model C is capable of providing good predictions of Mw and Wg simultaneously for the experiments carried out at 90°C. The present study showed an analysis in which the models can complement each other, providing subsidies for the development of a unified model.
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Hung, Chuan-Hsi. "Synthesis and Characterization of Carbonized Poly (Divinylbenzene) Microspheres for Carbon/Nanodiamond/Polymer-Based Core-Shell Materials and Applications of This Mixed-Mode Phase to High-Performance Liquid Chromatography." BYU ScholarsArchive, 2015. https://scholarsarchive.byu.edu/etd/5497.
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This work focuses on improving the quality of carbon-based core-shell materials for high performance liquid chromatography (HPLC) via the characterization of the core materials, and also the development of chromatographic methods (separations) for them. In the early part of this work, I applied organic synthesis to make uniform, spherical poly(divinylbenzene) (PDVB) microspheres, and then carbonized them to prepare carbon core materials for core-shell particle synthesis. Here, I studied in detail the surface and material properties of these particles with multiple instruments, which allowed me to describe the physical and chemical changes that took place during each treatment. The uniform, spherical carbon core materials greatly improved the efficiency of the previously developed carbon-based core-shell HPLC columns from ca. 70,000 plates per meter (N/m) to ca. 110,000 N/m for various alkyl benzenes. Later, I focused on generating application notes to showcase these mixed-mode HPLC columns. Here, liquid chromatography mass spectrometry (LC-MS) was used for the detection of analytes that lack chromophores for UV detection. In this dissertation, Chapter 1 contains a historical background and theory of HPLC along with a review of the use of carbon-based core-shell materials for elevated pH and temperature applications. Chapter 2 describes the improvement of the efficiency of carbon-based materials for HPLC using carbonized PDVB microspheres as the carbon core material. Chapter 3 is a study on the characterization of carbonized PDVB microspheres with multiple instruments. Chapter 4 describes the separation of cannabinoids using three types of carbon-based mixed-mode HPLC columns. Chapter 5 consists of (i) guidelines for the retention mechanism of the core-shell particles that have been commercialized for chromatography by Diamond Analytics, a US Synthetic Company in Orem, Utah, and (ii) application notes for these columns. Finally, Chapter 6 discusses possible future work.
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THAM-TRAN, THANH-THUY. "Synthese d'un support pour la chromatographie d'affinite des proteines : greffage du poly (methacrylate de glycidyle) sur un gel microporeux de poly (styrene-co-divinylbenzene)." Strasbourg 1, 1989. http://www.theses.fr/1989STR13023.
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Support pour la chromatographie hplc. Ce gel etant hydrophobe, son enrobage par un polymere hydrophile s'avere necessaire pour qu'il puisse etre utilise dans la separation des proteines en milieu aqueux. Les chlores benzyliques sont substitues par le thioacetate de potassium, l'hydrolyse des thioesters obtenus conduit a des fonctions thiol agissant comme agent de transfert dans le greffage radicalaire
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Lima, Wolney Arruda de. "Síntese e caracterização de compósitos polianilina/poli(estireno-co-divinilbenzeno) para Adsorção de Ânions [SnCl4]²-." Universidade Federal de Goiás, 2013. http://repositorio.bc.ufg.br/tede/handle/tede/3509.
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In this work were prepared and characterized polyaniline/poly(styrene-co-divinylbenzene) composites by in situ oxidative polymerization of aniline in the pores of styrene-divinylbenzene copolymers. The aim was to obtain composites with high specific surface areas and total pore volumes for use as adsorbents of complex anions [SnCl4]2-. The copolymers with 29 and 84 % of divinylbenzene (DVB) were called PStyDVB 29 and PStyDVB 84, respectively. They were synthesized by suspension polymerization in the presence of inert diluents like toluene and heptane to obtain mesoporous beads with sizes in the range of 400 to 800 μm. Before the oxidative polymerization, the copolymers were swelled with aniline and ethanol mixture at volumetric ratio 20:80. The oxidative polymerization of aniline in the copolymers was carried out using benzoyl peroxide as an oxidant in the presence of hydrochloric or nitric acid as dopant at 25°C in three polymerization cycles. The materials were characterized by infrared spectroscopy with Fourier transform (FTIR), elemental analysis (CNHS), X ray diffraction, thermogravimetry, nitrogen adsorption (specific surface area and pore volume), Scanning Electron Microscopy and Atomic Absorption spectrophotometry. Elemental analysis indicated that the composite doped with HCl adsorb higher amounts of polyaniline (PANI) than using HNO3. The FTIR spectra and X-ray diffraction patterns of the composites were similar to the ones of the copolymers due the low amounts of PANI incorporated. The copolymers had lower thermal stability than composites, and the copolymer PStyDVB 84 had higher thermal stability due to a higher crosslinking degree. The specific surface areas (SBET) and pore volume (Vp) of the composites showed a decrease compared to the respective copolymers, due to the incorporation of polyaniline by homogeneously distributed inside and outside surfaces. The increasing of DVB content in the composites and copolymers favored the formation of high specific surface areas and pore volumes. The adsorption of anion complex [SnCl4]2- by the composites occurred by ion exchange of ions Cl- or NO3-. The results showed that the complex anions [SnCl4]2- adsorption increased with the increasing of hydrochloric acid and tin ion (II) concentrations. The complex anions [SnCl4]2- adsorbed more on the composite PANI/PStyDVB 84 HNO3, although it showed the lowest PANI content, the highest specific surface area and pore volume compared to the other composites. It can be concluded that the anion complex [SnCl4]2- adsorption depends on the number of binding sites and on the porous structure of the composites.
Neste trabalho, foram preparados e caracterizados compósitos Polianilina/Poli(estireno-co-divinilbenzeno), através da polimerização oxidativa in situ da anilina nos poros dos copolímeros estireno e divinilbenzeno. O objetivo foi obter compósitos com altas áreas superficiais específicas e volume de poros totais, para utilização como adsorventes de ânions complexo [SnCl4]2-. Os copolímeros com 29 e 84 % de divinilbenzeno (DVB) foram denominados PStyDVB 29 e PStyDVB 84, respectivamente, e sintetizados através de polimerização em suspensão, na presença de diluentes inertes tolueno e heptano para obtenção de pérolas com estrutura mesoporosa e tamanhos na faixa de 400 e 800 μm. Antes da polimerização oxidativa, os copolímeros foram intumescidos com mistura de anilina e etanol, na razão volumétrica 20:80. A polimerização oxidativa da anilina nos copolímeros foi realizada com peróxido de benzoíla, como oxidante, na presença de ácido clorídrico ou nítrico como dopante a 25°C, em três ciclos de polimerização. Os materiais foram caracterizados por espectroscopia de Infravermelho com Transformada de Fourier, Análise Elementar (CNHS), Difratometria de Raios X, Termogravimetria, Adsorção Física de Nitrogênio (área específica e volume de poros), Microscopia Eletrônica de Varredura e espectrofotometria de Absorção Atômica. A análise elementar indicou que os compósitos dopados com HCl, adsorveram maiores quantidades de Polianilina (PANI) do que com o uso de HNO3. Os espectros de FTIR e difratogramas de Raios X dos compósitos assemelharam-se aos dos copolímeros, pela baixa quantidade de PANI incorporada. Os copolímeros apresentaram menor estabilidade térmica que os compósitos, sendo que o copolímero PStyDVB 84 apresentou maior estabilidade térmica, devido a um maior número de ligações cruzadas. As medidas de áreas superficiais específicas (SBET) e o volume de poros (Vp) dos compósitos apresentaram diminuição em relação aos respectivos copolímeros, devido à incorporação da Polianilina distribuída homogeneamente pela superfície interna e externa. O copolímero PStyDVB 84 e seus compósitos apresentaram altas áreas superficiais específicas e volumes de poros devido ao maior teor de DVB. A adsorção de ânions complexo de [SnCl4]2- pelos compósitos ocorreu pelo processo de troca iônica de íons Cl- ou NO3-. Os ânions complexo [SnCl4]2- foram mais adsorvidos com a elevação das concentrações do ácido clorídrico e do íon estanho (II) em solução. Os ânions complexos [SnCl4]2- adsorveram mais no compósito PANI/PStyDVB 84 HNO3, sendo que ele apresentou o menor teor de PANI, a maior área superficial específica e o maior volume de poros em comparação com os demais compósitos. Pode ser concluído que a adsorção dos ânios complexo [SnCl4]2- depende do número de sítios ligantes e da estrutura porosa do compósito.
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Limé, Fredrik. "Synthesis and modification of monodisperse polymer particles for chromatography." Doctoral thesis, Umeå universitet, Kemi, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-1948.
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Liquid chromatography is an analytical technique that is constantly facing new challenges in the separation of small molecules and large biomacromolecules. Recently the development of ultra high pressure liquid chromatography has increased the demand on sturdy particles as stationary phase. At the same time the particle size has decreased to sub-2 µm and packed into shorter analytical columns. This thesis deals with the development of new ways of preparing particulate polymer materials using divinylbenzene (DVB) as crosslinker. It includes a novel procedure for synthesizing monodisperse polymer particles by photoinitiated precipitation polymerization. A 150 W short arc xenon lamp was used to initiate the polymerizations. The synthesized particles are monodisperse and have an average particle size ranging from 1.5 to 4 μm depending on reaction conditions and have subsequently been used as grafting templates. The surface of DVB particles contains residual vinyl groups that serve as anchoring points for further functionalization via a variety of grafting schemes. Copolymerization with incorporation of 2,3-epoxypropyl methacrylate yielded pendant oxirane groups on the particle surface. Atom transfer radical polymerization (ATRP) was used to graft methacrylates from the surface resulting in a core-shell type material. A “grafting to” scheme was used to attach pre-made sulfopropyl methacrylate telomers onto particles containing oxirane rings.Populärvetenskaplig sammanfattning på svenska: Vätskekromatografi är en analytisk kemisk teknik som ständigt står inför nya utmaningar när det gäller att separera allt från små organiska föreningar till stora makro¬molekyler. Denna avhandling beskriver tillverkning av polymera partiklar med exceptionellt jämn storleksfördelning och ytmodifiering av dessa, för användning som stationärfas i kromatografi¬kolonner. Polymeriserings¬tekniken som används är utfällnings¬polymerisering där lösningen UV-bestrålas av en 150 W xenonlampa. Monomeren (byggstenen) löses tillsammans med en intiator i ett lösningsmedel och efterhand som polymeriseringen fortskrider faller polymerpartiklarna ut. Polymerpartiklarna är gjorda av monomeren divinylbensen som fungerar som en tvärbindare, dvs att den länkar ihop flera kedjor till ett hårt litet nystan. Partiklarna växte till en storlek på 1,5 till 4 µm under två till fyra dygn. Efter tillverkningen är partiklarnas yta täckta av vinylgrupper som kan användas för att fästa funktionella polymerkedjor. Genom att tillföra monomeren 2,3-epoxipropyl¬metakrylat i polymeriseringen kunde man desutom få en partikelyta som innehöll epoxigrupper. Epoxigrupperna användes för att fästa positivt laddade polymerkedjor av bestämd längd. Materialet packades i en kromatografikolonn och användes för att separera en testlösning bestående av fyra proteiner. Partiklarna användes även som bas för ymppolymerisering där den vinyltäckta ytan fått reagera med vätebromid. Detta gör att partiklarna blir stora makroinitiatorer som kan användas för att på ett kontrollerat sätt låta polymerkedjor växa från ytan. I en undersökning ympades 2,3-epoxypropylmetakrylat från ytan på partiklarna och resultatet blev ett tjockt ytskikt. Epoxigrupperna kunde sedan hydrolyseras till dioler vilket gjorde partiklarna mer hydrofila.
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Peyton, Daniel Junior. "Nitrogen-compound removal by ion exchange a model system study of the effect of nitrogen-compound type on the removal performance of two sulfonated styrene/divinylbenzene ion-exchange resins." Ohio : Ohio University, 1990. http://www.ohiolink.edu/etd/view.cgi?ohiou1183467365.
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Fournier, Clara. "Hydrophilisation de billes de polystyrène-divinylbenzène par adsorption de dérivés amphiphiles du dextrane : préparation et caractérisations structurales de nouveaux support pour la chromatographie des protéines." Vandoeuvre-les-Nancy, INPL, 1996. http://docnum.univ-lorraine.fr/public/INPL_T_1996_FOURNIER_C.pdf.
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De nouvelles phases stationnaires pour la chromatographie liquide haute performance des protéines ont été préparées à partir de microsphères poreuses de polystyrène-divinylbenzène. Ce matériau étant très hydrophobe, il est nécessaire d'en modifier la surface afin de le rendre compatible avec la nature des biomolécules à séparer. Le procédé utilisé consiste à adsorber sur les particules, un polymère hydrophile tel que le dextrane. L’introduction de groupes phenoxy sur ce polysaccharide, à différentes concentrations, conduit à des dérivés amphiphiles capables de s'adsorber fortement sur le polystyrène. La couche de polymère déposée est stabilisée, dans les conditions optimales, par réticulation chimique à l'epichlorhydrine. Le taux de groupements phenoxy fixés sur le dextrane n'a pas une grande influence sur la quantité maximale de polymère qui peut être déposée sur le polystyrène mais est déterminant quant à l'aptitude des matériaux obtenus à adsorber les protéines. La porosité des supports préparés est étudiée tant à l'état sec par porosimétrie au mercure et par adsorption d'azote qu'à l'état solvate dans divers milieux aqueux et organiques par chromatographie d'exclusion stérique. Elle dépend non seulement de la composition et de la conformation de la couche adsorbée mais aussi de l'aptitude des dextranes modifiés à s'associer par le biais d'interactions phenoxy-phenoxy. Finalement, des billes poreuses de polystyrène, modifiées par adsorption à saturation d'un dextrane présentant un taux élevé en groupes phenoxy, sont testées en chromatographie d'exclusion stérique des protéines. Le dextrane étant un polymère facilement fonctionnalisable, de tels supports sont utilisables pour d'autres modes de chromatographies ; un exemple de purification de la trypsine par chromatographie d'affinité est donné
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Neto, Mario Piccaglia. "Preparação e caracterização de microesferas poliméricas à base de poli(ácido metacrílico-co-divinilbenzeno) obtidas por polimerização por precipitação." Universidade do Estado do Rio de Janeiro, 2013. http://www.bdtd.uerj.br/tde_busca/arquivo.php?codArquivo=5072.
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Neste trabalho foi feito um estudo sobre a preparação e caracterização de microesferas poliméricas à base de poli(ácido metacrílico-co-divinilbenzeno) por polimerização por precipitação. As partículas foram sintetizadas e analisadas em diferentes condições de reação. Partículas esféricas políméricas foram sintetizadas na faixa de 1,66 - 8,41 m, assim como partículas no estado de microgel. As partículas foram caracterizadas pelas técnicas de espalhamento de luz dinâmica (DLS), análise termogravimétrica (TGA), espectroscopia na região do infravermelho (FTIR), adsorção de nitrogênio pelos métodos BET (Brunauer, Emmett e Teller) e BJH (Barret, Joyner e Halenda), microscopia ótica, microscopia eletrônica de varredura, e testes de razão de inchamento. A análise das partículas foi feita para verificar a influência da mudança na composição de comonômeros, grau de reticulação, relação de monômeros totais/diluentes em massa/volume (g/100 mL), e quanto à relação volumétrica de diluentes. Verificou-se que houve um aumento no tamanho das partículas e da resistência térmica com a diminuição da fração molar de MAA (ácido metacrílico). Na preparação de partículas com fração molar de 50% de MAA, e relação volumétrica acetonitrila/tolueno de 75/25, quanto maior a relação de monômeros totais/diluentes (g/100 mL), maior o tamanho e o rendimento das partículas. Com a mudança da relação volumétrica de diluentes, houve mudança nas características de porosidade, tamanho das partículas, e grau de inchamento das partículas, sendo que na relação volumétrica acetonitrila/tolueno de 50/50, houve formação de microgelThe preparation and characterization of polymeric microspheres based on poly(methacrylic acid-co-divinylbenzene) by precipitation polymerization was reported. The particles were synthesized and analyzed at different reaction conditions. Spherical polymer particles were synthesized in the range from 1,66 to 8,41 m, in addition to microgel particles. The particles were characterized by dynamic light scattering (DLS), thermogravimetric analysis (TGA), infrared spectroscopy (FTIR), nitrogen adsorption methods by BET (Brunauer, Emmett and Teller) and BJH (Barrett, Joyner and Halenda), optical microscopy, scanning electron microscopy, and swelling ratio tests. The particles analysis was made to determine the influence of the change in comonomer composition, degree of crosslinking, ratio of total monomers/diluents by weight / volume (g/100 mL), and the volume ratio of diluents. It was found that there was an increase in particle size and thermal resistance with decreasing molar fraction of MAA (methacrylic acid). In preparing particles with the mole fraction of 50% MAA, and volume ratio acetonitrile/toluene 75/25, the larger the ratio of total monomers/diluents (g/100 mL), the larger the particle size and yield. By changing the volume ratio of diluents, there was a change in the characteristics of porosity, particle size and degree of swelling of the particles, and in the volume ratio acetonitrile / toluene of 50/50, there was microgel formation
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Araujo, Renata Bastos de. "Preparação e avaliação de resinas biocidas impregnadas com iodo a partir de resinas comerciais de estireno e divinilbenzeno." Universidade do Estado do Rio de Janeiro, 2013. http://www.bdtd.uerj.br/tde_busca/arquivo.php?codArquivo=5197.
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Neste trabalho, foram empregadas duas resinas comerciais de caráter fortemente básico. Ambas tendo como base copolímeros de estireno e divinilbenzeno (DVB), sendo que a VPOC 1950 contém em sua composição grupos quaternários de amônio do tipo 1, que apresentam três grupos metila e a VPOC 1960 grupos quaternários de amônio do tipo 2, que apresentam um grupo etanoíla e dois grupos metila. As resinas comerciais citadas foram escolhidas por apresentarem grande capacidade de troca iônica, estabilidade e grupos funcionais de interesse para a impregnação com iodo. As resinas foram impregnadas com iodo por meio de três metodologias distintas, uma solução metanólica de iodo 0,08 mol/L com e sem iodeto de potássio 0,14 mol/L, e iodo 0,08 mol/L em heptano. As resinas foram caracterizadas por área específica, volume do poro, grau de inchamento, microscopia ótica, espectrometria de infravermelho por transformada de Fourier (FTIR), análise elementar, termogravimetria, microscopia eletrônica de varredura e determinação do iodo fixado por iodometria. A avaliação da atividade biocida foi realizada através do método da contagem em placas, utilizando-se uma cepa de Escherichia coli ATCC11775 em concentrações de 103 a 107 células/mL. Todas as resinas impregnadas mostraram atividade bactericida significante devido à presença de iodo correlacionada às características da resina, tais como: grupos funcionais, tamanho e formato dos poros. Para efeito de comparação, foram realizados ensaios bactericidas com as resinas de partida para comprovação ou não da ação bactericida ser atribuída somente ao iodoIn this study, we employed two commercial resins strongly basic character. Both based on copolymers of styrene and divinylbenzene (DVB), and the VPOC 1950 contains in its composition quaternary ammonium groups of the type 1 (has three methyl groups) and VPOC 1960 quaternary ammonium groups of the type 2 (where a group ethanol replaces one of the methyl groups). The aforementioned commercial resins were chosen because they have a high ion exchange capacity, stability and functional groups of interest for impregnation with iodine. The resins were impregnated with iodine by three different methodologies, a methanol solution of 0.08 mol/L iodine with and without 0.14 mol/L potassium iodide and 0.08 mol/L iodine in heptane. The resins were characterized by surface area, pore volume, degree of swelling, optical microscopy, infrared spectroscopy by Fourier transform (FTIR), elemental analysis, thermogravimetry, scanning electron microscopy and determination of iodine prescribed by iodometry. The biocidal activity evaluation was performed by the method of plate counting, using a strain of Escherichia coli ATCC11775 at concentrations 103-107 cells/ml. All resins impregnated showed significant bactericidal activity due to the presence of iodine correlated characteristics of the resin, such as functional groups, size and shape of the pores. For comparison, tests were performed with bactericidal resins departure for confirmation or not of bactericidal only be attributed to iodine
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Čirbulytė, Jolanta. "Analizės metodų taikymas migracijos procesui iš polimerinių medžiagų tirti." Master's thesis, Lithuanian Academic Libraries Network (LABT), 2006. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2006~D_20060627_145029-14194.
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Evaluation of solid-phase microextraction as an alternative official method for analysis of polymers migration. The objective this study was to compaire the official methods with solid-phase microextraction (SPME)for the analysis of compounds migrating from cross-linked polyethylene into water. A medium polarity polydimethylsiloxane/divinylbenzene (PDMS/DVB)was proved most efficient for the SPME extraction. However, when applied to water samples in contact with polyethylene, SPME proved to be immensely more sensitive and have a greater extraction range than liquid-liquid extraction (LLE). It was proved the migration of Phenol, 2,4-bis(1,1-dimethylethyl). Concentration of this compound 0,6-0,15mg/l.It was proved the migration of Cyclohexadiene-1,4-dione, 2,6-bis(1,1-dimethylethyl).
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Barbosa, Danns Pereira. "Redução de espécies nitrato em água sobre catalisadores bimetálicos de paládio." reponame:Repositório Institucional da UFBA, 2011. http://www.repositorio.ufba.br/ri/handle/ri/10076.
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CAPES
O amplo uso de fertilizantes nitrogenados, bem como os sistemas de saneamento rudimentares e as atividades pecuárias, têm aumentado a contaminação das águas subterrâneas e, portanto, da água potável. Devido aos graves riscos das espécies nitrato para a saúde humana, tem sido dispensada muita atenção para o desenvolvimento de tecnologias para removê-las da água. Dessa forma, neste trabalho foram preparados catalisadores bimetálicos de paládio e estanho ou índio suportados em estireno-divinilbenzeno (Sty-DVB) sulfonado, a fim de desenvolver catalisadores eficientes para a remoção das espécies nitrato da água. O suporte foi sintetizado por polimerização em suspensão, enquanto os catalisadores bimetálicos foram preparados por dois métodos: impregnações sucessivas e redução catalítica. Foram obtidos catalisadores com 5% m/m de paládio e vários teores (0,5, 2 e 4% m/m) de estanho ou índio, que foram caracterizados por espectroscopia no infravermelho com transformada de Fourier, adsorção de nitrogênio, análise química elementar, difração de raios X, termogravimetria e microscopia eletrônica de varredura. Os catalisadores foram avaliados na redução das espécies de nitrato na água, na presença e na ausência de dióxido de carbono. Verificou-se que o suporte não adsorve nitrato, nitrito e amônia e não apresenta atividade na redução das espécies nitrato. Os catalisadores com índio foram mais ativos na redução de espécies nitrato, e menos seletivos a nitrogênio, do que os catalisadores com estanho. Além disso, os catalisadores com estanho e preparados por redução catalítica foram mais ativos do que aqueles preparados por impregnações sucessivas. Um comportamento inverso foi observado com os catalisadores contendo índio. Com a maioria das amostras, o dióxido de carbono aumentou a atividade, reduziu a seletividade a nitrito e aumentou a produção das espécies amônio. Os melhores desempenhos catalíticos foram apresentados pelas amostras 5%Pd2%Sn/Sty-DVB, (atividade=15,2 cmol. min-1.g-1; seletividade a nitrogênio = 98%) e 5%Pd0,5%In/Sty-DVB (atividade= 18,8 cmol.min-1.g-1; seletividade a nitrogênio = 89%), preparadas por impregnações sucessivas e redução catalítica , respectivamente.
Salvador
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Diogo, Diego Dornelas. "Avaliação da influência da interação polímero-solvente sobre a porosidade de copolímeros de acrilonitrila e divinilbenzeno obtidos por polimerização em suspensão." Universidade do Estado do Rio de Janeiro, 2011. http://www.bdtd.uerj.br/tde_busca/arquivo.php?codArquivo=2713.
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Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorNeste trabalho, copolímeros à base de acrilonitrila e divinilbenzeno foram sintetizados, utilizando a técnica de polimerização em suspensão, na presença de três agentes porogênicos diferentes (álcool isoamílico, metil-etil-cetona e tolueno). Esses copolímeros foram caracterizados por meio da determinação da densidade aparente, do volume e diâmetro de poros, por microscopia ótica e microscopia eletrônica de varredura e foram avaliados quanto à capacidade de inchamento em heptano e tolueno. O principal intuito dessa pesquisa foi correlacionar a formação da estrutura porosa desses materiais com os principais parâmetros de síntese (grau de diluição dos monômeros, poder solvatante do diluente e teor do agente de reticulação). Desses parâmetros, o que mais influenciou na formação da estrutura porosa desses materiais foi o poder solvatante do diluente. A teoria dos parâmetros de solubilidade de Hansen e Hildebrand foi utilizada com o intuito de fazer uma previsão das características porosas dos copolímeros à base de acrilonitrila e divinilbenzeno sintetizados na presença de três diluentes diferentes. Dentre esses diluentes, o álcool isoamílico foi o pior solvente para os copolímeros de AN-DVB, em todos os teores de agente de reticulação e em todas as diluições utilizadas. O tolueno foi o melhor solvente para os copolímeros que contêm altos teores de agente de reticulação. Estas observações estão de acordo com as previsões dos parâmetros de solubilidade de Hansen e Hildebrand. A metil-etil-cetona foi o melhor solvente para os copolímeros que contêm teores intermediários de agente de reticulação. Esta observação só está condizente com o parâmetro de solubilidade de Hansen.
In this work, acrylonitrile-divinylbenzene copolymers were synthesized using the technique of suspension polymerization in the presence of three different solvents (isoamyl alcohol, methyl-ethyl-ketone and toluene). These copolymers were characterized by apparent density, pore volume and pore diameter, optical and scanning electron microscopy, and were evaluated for their ability to swell in heptane and toluene. The principal aim of this research was to correlate the porous structure formation of these materials, with the main synthesis parameters (degree of dilution, solvating power of the diluent and crosslinking degree). Among these parameters, the most important on the formation of the materials porous structure was the solvating power of the diluent. The theory of solubility parameters of Hansen and Hildebrand was used in order to make a prediction of the porous characteristics of acrylonitrile-divinylbenzene copolymers synthesized in the presence of three different diluents. Among these solvents, the isoamyl alcohol was the worst solvent for acrylonitrile-divinylbenzene copolymers, at all levels of crosslinking degree and at all dilutions used. Toluene was the best solvent for the copolymers containing high levels crosslinking degree. These observations are consistent with the predictions of the solubility parameters of Hansen and Hildebrand. The methyl-ethyl-ketone was the best solvent for the copolymers containing intermediate crosslinking degree. This observation is only consistent with the Hansen solubility parameters. In this work, acrylonitrile-divinylbenzene copolymers were synthesized using the technique of suspension polymerization in the presence of three different solvents (isoamyl alcohol, methyl-ethyl-ketone and toluene). These copolymers were characterized by apparent density, pore volume and pore diameter, optical and scanning electron microscopy, and were evaluated for their ability to swell in heptane and toluene. The principal aim of this research was to correlate the porous structure formation of these materials, with the main synthesis parameters (degree of dilution, solvating power of the diluent and crosslinking degree). Among these parameters, the most important on the formation of the materials porous structure was the solvating power of the diluent. The theory of solubility parameters of Hansen and Hildebrand was used in order to make a prediction of the porous characteristics of acrylonitrile-divinylbenzene copolymers synthesized in the presence of three different diluents. Among these solvents, the isoamyl alcohol was the worst solvent for acrylonitrile-divinylbenzene copolymers, at all levels of crosslinking degree and at all dilutions used. Toluene was the best solvent for the copolymers containing high levels crosslinking degree. These observations are consistent with the predictions of the solubility parameters of Hansen and Hildebrand. The methyl-ethyl-ketone was the best solvent for the copolymers containing intermediate crosslinking degree. This observation is only consistent with the Hansen solubility parameters.
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Bento, Heitor Buzetti Simões. "Preparação e caracterização de biocatalisadores a partir de lipases imobilizadas em partículas magnetizadas de poli (estireno-co-divinilbenzeno)." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/97/97137/tde-20092016-101604/.
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Este trabalho teve como objetivo sintetizar e caracterizar uma matriz híbrida estável de poli(estireno-co-divinilbenzeno) magnetizado pela adição de magnetita (Fe3O4) e avaliar seu potencial como suporte para a imobilização de lipases. A matriz híbrida foi sintetizado pela técnica de polimerização em suspensão utilizando dos monômeros de estireno e divinilbenzeno e ao qual foram adicionadas partículas de magnetita preparadas por coprecipitação dos íons Fe+2 e Fe+3. A caracterização foi realizada pelas técnicas de microscopia eletrônica de varredura (MEV), espectroscopia na região do infravermelho por transformada de Fourier (FTIR), difratometria de raios-X (DRX) e magnetização de amostra vibrante (VSM), comparando os materiais magnetizados e não magnetizados. Os biocatalisadores foram preparados pela imobilização da lipase de Candida rugosa (LCR) e lipase PS Burkholderia cepacia (LPS) via adsorção física e foram caracterizados em função da influência de pH e temperatura na atividade hidrolítica, parâmetros cinéticos, estabilidade térmica, estabilidade operacional e estabilidade de estocagem. O derivado de LCR foi aplicado em reações de esterificação e o derivado de LPS em reações de transesterificação. Os resultados obtidos pelas análises de FTIR, DRX e VSM confirmaram que a magnetita foi incorporada ao polímero, gerando atração das partículas por um campo magnético externo. A caracterização bioquímica indicou forte influência do pH na atividade hidrolítica, apresentando ponto ótimo próximo a 8,0 tanto para as lipases livres quanto imobilizadas. Os biocatalisadores magnetizados preparados apresentaram bom desempenho em todos os aspectos, o derivado da lipase de Candida rugosa alcançou conversões entre 89-94% nas reações de esterificação, revelando tempo de meia vida de t1/2=52 dias na estabilidade operacional. O derivado de Burkholderia cepacia atingiu rendimentos próximos a 80% nas reações de transesterificação com t1/2=40 dias. A imobilização aumentou a estabilidade térmica das lipases em 50 vezes no caso da LCR e em 2,3 vezes para a LPS. Estes resultados indicam que o material híbrido magnetizado sintetizado possui grande potencial para ser utilizado como suporte na imobilização de enzimas com aplicação em reações de interesse industrial.This study aimed to synthesize and characterize a stable hybrid matrix of poly (styrene-codivinylbenzene) magnetized by the addition of magnetite (Fe3O4) and evaluate its potential for application in the immobilization of lipases, by characterization of the prepared biocatalysts. The support was synthesized by the suspension polymerization technique by applying styrene and divinylbenzene monomers and adding magnetite particles synthesized by co-precipitation of Fe + 2 and Fe + 3. The characterization of the material was performed by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), vibrating sample magnetization (VSM), by comparison of the magnetized and the not magnetized particles. The biocatalysts were prepared by immobilization of lipase from Candida rugosa (CRL) and lipase from Burkholderia cepacia (Lipase PS) via physical adsorption and they were characterized according to the influence of pH and temperature on the hydrolytic activity, kinetic parameters, thermal stability, operational stability and storage stability. The CRL derivative was applied in esterification reactions and the lipase PS derivative was applied in transesterification reactions. The results obtained by the analysis FTIR, XRD and VSM confirmed the magnetite was successfully incorporated into the polymer and generated the atraction for an external magnetic field. Biochemical characterization indicated a strong influence of pH on the hydrolytic activity, showing better results on pH around 8,0 for free and both immobilized lipases. The magnetized biocatalysts prepared had good performance in all respects, derivative from Candida rugosa lipase reached 89-94% conversion in esterification reactions showing half-life of operational stability t1 / 2 = 52 days. The immobilized lipase from Burkholderia cepacia reached yields close to 80% in transesterification reactions presenting t1/2 = 40 days. Immobilization increased the thermal stability of lipase by 50 times in the case of CRL and 2,3 times for Lipase PS. These results indicate that the magnetized hybrid material synthesized has great potential to be used as a support for the immobilization of enzymes for use in reactions of industrial interest.
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Castanharo, Jacira Aparecida. "Preparação de microesferas poliméricas à base de estireno, acetato de vinila e divinilbenzeno com propriedades magnéticas." Universidade do Estado do Rio de Janeiro, 2011. http://www.bdtd.uerj.br/tde_busca/arquivo.php?codArquivo=2712.
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Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorMicroesferas poliméricas magnéticas à base de estireno (STY), divinilbenzeno (DVB), acetato de vinila (VAc) e ferro foram preparadas via polimerização em suspensão e semissuspensão. Foram estudadas as influências da concentração de VAc adicionado na polimerização e a presença de ferro sobre as características das partículas poliméricas obtidas. Estas partículas foram caracterizadas por espectrometria de absorção na região do infravermelho (FT-IR), análise térmica (TGA/DTA), microscopia óptica (MO), microscopia eletrônica de varredura (SEM) e magnetometria de amostra vibrante (VSM). Foram obtidas com sucesso microesferas poliméricas com propriedades magnéticas à base de estireno, divinilbenzeno e acetato de vinila. Estes materiais apresentaram bom controle morfológico, com maior rendimento na faixa de 120 a 75 m. Apresentaram também boas propriedades magnéticas (22,62 a 73,75 emu/g) com comportamento próximo de materiais superparamagnéticos e boa estabilidade térmica (444 C)
Magnetic polymeric microspheres based on styrene (STY), divinylbenzene (DVB), ethylene vinyl acetate (VAc) and iron were prepared via suspension and half suspension polymerization. The influence of the concentration of VAc and iron added to the polymerization on the characteristics of polymeric particles obtained were studied. These particles were characterized by infrared spectrometry (FT-IR), thermal analysis (TGA / DTA), optical microscopy (OM), scanning electron microscopy (SEM) and vibrating sample magnetometry (VSM). Polymeric microspheres with magnetic properties based on styrene, divinylbenzene and vinyl acetate were obtained. These materials showed good morphological control and large yield range from 120 to 75 micrometers. They also showed comparable magnetic properties (from 22.62 to 73.75 emu/g) to superparamagnetic materials and good thermal stability (444 C)
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Bouças, Thiago Alexandre de Oliveira. "Efeito de alguns parâmetros de síntese na obtenção de copolímeros à base de estireno e divinilbenzeno com propriedades magnéticas." Universidade do Estado do Rio de Janeiro, 2008. http://www.bdtd.uerj.br/tde_busca/arquivo.php?codArquivo=880.
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Nesta dissertação, microesferas poliméricas com propriedades magnéticas à base de estireno e divinilbenzeno foram sintetizadas por polimerização em suspensão. O material utilizado para conferir as propriedades magnéticas foi magnetita sintetizada em laboratório. Foram estudados os efeitos da modificação da magnetita com ácido oleico, da velocidade de agitação, do teor de iniciador e de teor de agente de suspensão sobre as características das partículas poliméricas obtidas. As microesferas foram caracterizadas quanto ao seu aspecto morfológico, à estabilidade térmica, ao tamanho e à distribuição do tamanho de partículas e quanto à suas propriedades magnéticas. Foram obtidos copolímeros com morfologia esférica e tamanho micrométrico, com propriedades magnéticas comparáveis a materiais superparamagnéticos. O tamanho de partícula foi afetado principalmente pela velocidade de agitação, enquanto que a distribuição deste tamanho foi fortemente influenciada pela alteração dos teores de iniciador e agente de suspensão. A magnetização de saturação para as microesferas ficou próxima dos valores encontrados na literatura, comparando-se resinas com o mesmo teor de material magnético. A modificação com ácido oleico foi considerada importante para a incorporação do material magnéticoIn this dissertation, polymeric microspheres with magnetic properties based on styrene and divinylbenzene were synthesized by suspension polymerization technique. In order to obtain magnetic properties, magnetite was synthesized in laboratory. The effects of magnetite modification with oleic acid, stirring velocity, concentration of initiator and concentration of stabilizer on the particles properties were studied. The magnetic microspheres were characterized according to morphology, thermal stability, particle size and its distribution and magnetic properties. It was verified that the microspheres presented spheric shape, micrometric size and magnetic properties comparable to superparamagnetic materials. Particle size was mainly affected by stirring velocity, while its dispersion was strongly affected by concentration of initiator and stabilizer. The saturation magnetization for the microshpheres was similar to the values reported in the literature, taking in account resins with the same content of magnetic material. The modification with oleic acid was considered important to the incorporation of the magnetic material
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Gaillard, Cédric (1971. "Elaboration de polymères et de composites pouvant servir de phase résorbable dans un ciment osseux : étude du contrôle de la distribution en taille de microbilles de poly(1,2-bis(méthyl 2-propénoyxy)éthane co divinylbenzène." Aix-Marseille 1, 2000. http://www.theses.fr/2000AIX11035.
Full textAbstract:
Dans le cas d'une perte de substance osseuse, il peut etre necessaire de recourir a un materiau synthetique pour pallier le manque d'os. Dans le but de permettre une colonisation osseuse, deux phases supplementaires ont ete incorporees dans un ciment commercial a base de 2,2-bishydroxy-3-(methylpropenoyloxy)propoxyphenyl-propane, composant habituel de ciments dentaires ou de materiaux de comblement osseux. La premiere phase, resorbable, doit laisser, apres sa disparition totale ou partielle, un espace poreux colonisable par le tissu osseux. La deuxieme phase, formee de microbilles macroporeuses de poly(1,2-bis(methylpropenoyloxy)ethane co divinylbenzene) (egdma), doit faciliter le flux des elements physiologiques au travers du ciment. Une premiere partie presente le composite pcpca, forme par association entre du poly(chlorure de 2-propenoyle) et du carbonate de calcium, qui reagit au contact du milieu physiologique pour produire du poly(acide 2-propenoique) resorbable. Cependant, l'etude experimentale de l'hydrolyse du pcpca a montre que l'acide chlorhydrique libere n'est pas suffisamment neutralise par le carbonate de calcium. Un nouveau composite presentant une meilleure biocompatibilite est alors prepare a partir du pcpca. Il peut alors constituer la phase resorbable du ciment. Dans une seconde partie, ce travail presente et verifie experimentalement les relations theoriques existant entre la tension interfaciale, la viscosite et la masse volumique de la phase aqueuse et le diametre maximal d'une distribution de microbilles d'egdma. Si l'on admet que la cassure des gouttelettes de monomere se produit par inertie, la theorie de kolmogoroff explique les resultats experimentaux obtenus si l'ecoulement est considere comme turbulent homogene et isotrope. Lorsque la division des gouttelettes s'effectue par abrasion visqueuse, la theorie developpee par taylor est conforme aux relations trouvees dans le cas ou l'ecoulement n'est plus turbulent.
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Formiga, Washington Jose Fernandes. "Preparação e caracterização de microesferas poliméricas com morfologia casca-núcleo e propriedades magnéticas à base de estireno e divinilbenzeno." Universidade do Estado do Rio de Janeiro, 2012. http://www.bdtd.uerj.br/tde_busca/arquivo.php?codArquivo=3571.
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Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorForam sintetizadas microesferas poliméricas com propriedades magnéticas e morfologia casca-núcleo por meio da técnica de polimerização em suspensão em duas etapas. O núcleo foi constituído por poli(estireno-co-divinilbenzeno) e magnetita modificada com ácido oleico. Foi avaliada a influência da velocidade de agitação e da concentração de iniciador sobre as características das microesferas utilizadas como núcleo (morfologia, tamanho de partículas, propriedades magnéticas e estabilidade térmica). A casca foi constituída por poli(estireno-co-divinilbenzeno) sem material magnético. Foi avaliado o método de adição da emulsão dos monômeros formadores da casca e o tempo de inchamento dos núcleos na emulsão. As microesferas casca-núcleo foram caracterizadas quanto ao seu aspecto morfológico e à estabilidade térmica. Os núcleos não apresentaram ciclos de histerese, estando assim próximos de um material com propriedades superparamagnéticas. O copolímero sintetizado com a maior velocidade de agitação e a menor concentração de iniciador foi o que apresentou o maior teor de ferro incorporado (3,317 %), a maior magnetização de saturação (2,99 emu/g) e o menor diâmetro médio de partículas (81 m). As microesferas casca-núcleo apresentaram apenas um estágio de degradação e as suas Tmáx foram menores do que a do núcleo. O mapa composicional de ferro confirmou a presença de magnetita na superfície das microesferas casca-núcleo
Polymeric microspheres with magnetic properties and core-shell morphology were synthesized by the technique of suspension polymerization in two stages. The core was constituted by poly(styrene-co-divinylbenzene) and magnetite coated with oleic acid. The influence of stirring rate and initiator concentration on microspheres characteristics (morphology, particle size, magnetic properties and thermal stability) was studied. The shell was constituted by poly(styrene-co-divinylbenzene) without magnetic material. It was also evaluated the methods of the monomers emulsion addition and the coress swelling time in the emulsion.. The microspheres were characterized by morphologic aspect and thermal stability. The cores did not presented hysteresis cycles, thus proving the superparamagnetic properties. Copolymer synthesized with the higher stirring rate and lower initiator concentration presented the higher incorporated iron content (3.317 %), higher saturation magnetization (2.99 emu/g) and the lower average particle diameter (81 m). Core-shell microspheres presented only one stage of degradation and the Tmáx were smaller than temperature of the cores. Iron compositional map confirmed the presence of magnetite on the surface of core-shell microspheres
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Valle, Aline Sol Da Silva. "Síntese, caracterização e avaliação da capacidade bactericida de copolímeros à base de 2-vinilpiridina funcionalizados." Universidade do Estado do Rio de Janeiro, 2009. http://www.bdtd.uerj.br/tde_busca/arquivo.php?codArquivo=2311.
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Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorNeste trabalho, dois copolímeros à base de 2-vinilpiridina (2Vpy), estireno (Sty) e divinilbenzeno (DVB) foram sintetizados empregando a técnica de polimerização em suspensão aquosa via radical livre. Os copolímeros com diferentes características morfológicas foram preparados variando a composição da mistura diluente, constituída por tolueno e n-heptano, solventes solvatantes e não solvatantes para as cadeias poliméricas. A caracterização estrutural desses materiais foi feita através de medidas de área específica, volume de poros, diâmetro médio de poros e densidade aparente. Além disso, esses materiais foram avaliados por microscopia ótica e eletrônica de varredura, por espectroscopia na região do infravermelho (FTIR), análise termogravimétrica (TGA) e análise elementar. Os copolímeros Sty-DVB-2Vpy foram modificados quimicamente através de reação de quaternização das unidades de 2Vpy usando dois reagentes: iodeto de metila e acrilonitrila. A quaternização dos copolímeros Sty-DVB-2Vpy foi confirmada através de espectroscopia de infravermelho, pelo aparecimento das bandas de absorção características do íon peridíneo e do grupo nitrila e também pela análise do comportamento térmico. Os produtos dessas reações foram submetidos à avaliação da capacidade bactericida através do método de contagem em placas contra suspensão de Escherichia coli. O copolímero do tipo gel quaternizado com iodeto de metila apresentou a maior ação bactericida registrada, com eficiência até a concentração de 104 células/mL. Contudo, a maioria dos materiais quaternizados não apresentou ação biocida significativa. Com o objetivo de maximizar a atividade bactericida dos materiais preparados, os copolímeros quaternizados e não quaternizados foram impregnados com iodo por meio de duas metodologias: em solução e em fase vapor. O teor de iodo incorporado foi quantificado por análise gravimétrica. Foi possível observar que os copolímeros quaternizados e impregnados com iodo se mostraram mais eficientes como agentes bactericidas que os copolímeros não funcionalizados impregnados com iodo. De uma forma geral, foi possível perceber que a ação bactericida dos polímeros é fruto da associação entre as suas características de porosidade, o grau de quaternização alcançado e o teor de iodo incorporado. Para efeito de comparação foram feitos também ensaios bactericidas com uma resina comercial à base de Sty-DVB com grupo amônio quaternário, VP OC 1950. Os testes mostraram que a resina comercial não possui atividade bactericida. A impregnação de iodo a essa resina comercial forneceu um material com ação biocida semelhante à do copolímero do tipo gel, quaternizado com iodeto de metila e impregnado com iodo
In this work two 2-Vinylpyridine-Styrene-Divinylbenzene copolymers with different porosity degrees were synthesized by aqueous suspension polymerization in the presence of diluent mixtures formed by toluene (solvating solvent) and n-heptane (nonsolvating solvent) in different proportions. Their structural characteristics were characterized by determination of surface area, average pore diameter and pore volume by BET/BJH, bulk density, optical and electron microscopies. In addition the chemical morphology those materials were characterized by FT-IR, elemental analysis and thermogravimetry. The pyridine units were quaternized using two reagents: methyl iodide and acrylonitrile. Those reactions were confirmed by FT-IR, the presence of characteristics bands of piridinium ion and nitrile group was used as a qualitative indication of the quaternizations reactions. The extension of those modifications was also evaluated by thermogravimetry. The antibacterial activities of the quaternized materials were determined towards 103 to 107 cells/mL dilutions of the auxotrophic (OHd5 k-12) Escherichia coli strain. The gel type copolymer quaternized with methyl iodide presented the better bactericidal action, with significant efficiency until 104 cells/mL, however most quaternized copolymers did not present significant bactericidal action. In order to maximize the bactericidal performance, the modified and unmodified copolymers were impregnated with iodine using two different methods: solution and vapor. The iodine incorporation was quantified by gravimetry. It was observed that the copolymers quaternized and impregnated with iodine presented higher biocidal action than the unmodified copolymers impregnated with iodine. It was verified that the biocidal action the polymers is a result of three contributions: porous characteristics of the supports, quaternization degree and iodine incorporation degree. The bactericidal performance of a commercial resin with quaternary ammonium groups, VP OC 1950, was also evaluated. The tests showed that the commercial resin did not present bactericidal efficiency. That resin impregnated with iodine presented bactericidal action similar to gel type copolymer quaternized with methyl iodide and impregnated with iodine.
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Queiroz, Carla do Nascimento. "Preparação e caracterização de microesferas poliméricas à base de metacrilato de glicidila e divinilbenzeno com propriedades magnéticas." Universidade do Estado do Rio de Janeiro, 2011. http://www.bdtd.uerj.br/tde_busca/arquivo.php?codArquivo=2707.
Full textAbstract:
Nesta Dissertação, foram sintetizadas microesferas poliméricas com propriedades magnéticas à base de metacrilato de glicidila e divinilbenzeno pela técnica de polimerização em suspensão. O material utilizado para conferir as propriedades magnéticas ao copolímero foi magnetita sintetizada no laboratório. Foram estudados os efeitos da modificação da magnetita com ácido oleico, da velocidade de agitação, do teor de agente reticulante, do teor de material magnético adicionado e do teor de agente de suspensão sobre as características das partículas poliméricas obtidas. As microesferas foram caracterizadas quanto ao seu aspecto morfológico, à estabilidade térmica, à incorporação de material magnético e quanto às suas propriedades magnéticas. A quantidade de partículas de ferro incorporadas foi afetada pela velocidade de agitação durante a síntese, pelo teor de material magnético adicionado, pela fase de dispersão do material magnético e pelo teor de monômeros no copolímero. A estabilidade térmica dos copolímeros foi afetada, principalmente, pelo teor de material magnético incorporado e pelo teor de monômeros, levando em consideração resinas com a mesma quantidade de material magnético adicionado. A magnetização de saturação para as microesferas foi afetada pelo teor de material magnético incorporado. A modificação da superfície da magnetita com ácido oleico foi considerada importante para a incorporação do material magnético na matriz do copolímero.Partículas poliméricas magnéticas com comportamento superparamagnéticos foram obtidas com morfologia esférica e magnetização de saturação de 7,11 (emu/g), utilizando razão molar de monômeros de 50/50 %, 1 % de PVA, 20 % de magnetita modificada com ácido oleico adicionada à fase orgânica e velocidade de agitação mecânica de 500 rpmIn this dissertation, polymeric microspheres with magnetic properties based on glycidyl methacrylate and divinylbenzene were synthesized by suspension polymerization technique. In order to obtain magnetic properties, magnetite particles modified by oleic acid were synthesized in laboratory. The effects of stirring rate, concentration of crosslink, the concentration of magnetite added and the concentration of stabilizer on the particles properties were studied. The magnetic microspheres were characterized according their morphology, thermal stability, incorporation of magnetite and their magnetic properties. The incorporate of iron particles content was mainly affected by stirring rate during the synthesis, by the content of magnetic material added, by the dispersion phase of magnetic material and by the monomers content in the copolymer. The thermal stability of copolymers was mainly affected by the content of magnetic material incorporated and by the monomers content, taking in account the resins with the same content of magnetic material added. The saturation magnetization for the microspheres was effected by the content of magnetic material incorporated. The modification with oleic acid was considered important to the incorporation of the magnetic material in the copolymer matrix.Magnetic polymeric particles with superparamagnetic behavior have been obtained with spherical morphology and saturation magnetization of 7.11 (emu/g). It was used monomers molar ratio of 50/50 %, 1% PVA, 20 % magnetite particles modified by oleic acid dispersion on organic phase and stirring rate of 500 rpm during the synthesis
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Gehrke, Maik [Verfasser]. "Funktionalisierung von Polystyren-Divinylbenzen-Harzen zur selektiven Festphasenextraktion von Aromastoffen / von Maik Gehrke." 2000. http://d-nb.info/959276637/34.
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Lin, Cheng-Lan, and 林正藍. "Sulfonamide Analyses by Capillary Electrochromatography using Poly(octadecene-divinylbenzene) Monolithic Column." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/99644165201810549579.
Full textAbstract:
碩士中原大學
化學研究所
97
In the thesis, capillary electrochromatography (CEC) technique was studied and divided into two parts. In the first-part of the study, development of organic polymer-based monolithic column was investigated. Poly(octadecene- divinylbenzene) (POD-DVB) was preparaed as novel stationary phase, which using vinylbenzyl trimethyammonium (VBTA) as charge-carried monomer provided EOF. The monolithic column was applied to eight sulfonamides separation by CEC. The effect of the polymerization condition of the stationary phase (ratios of charged-carried monomer, monomer level, effective length) and acetonitrile content in the mobile phase were examined. The separation of eight sulfonamides was completed in 15 min.. Finally, the CEC method coupled step gradient elution or on-line sample concentration which were examined for the separation efficiency of sulfonamides. The research indicated that step gradient elution was effective in reducing the peak tailing, and the separation time was shortened from 15 to 11 min.. The combination of on-line sample concentration detection limit of sulfonamide compounds was improved to about 200 times. The detection limit was in the range of 9.2 to 28.2 ng/mL. This method has been applied to food analyses. A trace amount of sulfonamide in milk was detected successfully. In the second-part of thesis, preparation of packed column was studied. Frits were prepared by using PS-DVB co-polymer (the optimum length was about 2 mm), and C18 silica was taken in as the stationary phase in packed column. The result showed that CEC packed column with good reproducibility was successfully prepared. The reproducibility of retention time was in the range 1.25 to 3.04 % (n=3). The C18 packed column was applied to the analyses of phthalate acid esters (PAEs), which combined with step gradient elution. The separation time can be shortened from original 70 to 18 min. when compared to isocratic elution.
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Lo, Tzu-Chiang, and 羅自強. "Preparation of poly(styrene-divinylbenzene) beads for chromatographic analysis of penicillins." Thesis, 1997. http://ndltd.ncl.edu.tw/handle/62235648503548874588.
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碩士國立中正大學
化學工程研究所
85
Monodisperse styrene-divinylbenzene copolymer ( PS-DVB ) particles were successfully prepared via a method of two-step polymerization in the research. The effects of the diluent, the molecular weight of the seeds, as well as the presence of polymeric porogen on the particle morphology andthe formation of porous structure were also studies. The polymer particlesbound with octadecyl( C18 ) groups and amino groups respectivelyresulted from different surface modifications were used as the sorbents for reversed-phase and normal-phase liquid chromatography of penicillin antibodies such as penicillin G ( Pen G ),6-aminopenicillinic acid (6-APA) and phenylacetic acid ( PAA ) . Using non-solvent as diluent, the concave deformation occurred on the surface of polymer particles. Microspheric particles without deformation wereobtained if the diluent used in the experiments was a good solvent. However,a very high molecular weight of seeds is the key factor of leading to no pore formation in the particle structure after solvent extraction. Introducinga low molecular weight of polymeric porogen in the seeds was effective for producing porous particles but with a polydispersed size distribution. The FTIRinspection proved that the modification reaction of particles was achieved forbonding with amino groups. Both the non-modified PS-DVB and PS-DVB-C18 particles were employed as the sorbents for analyzing Pen G, 6-APA and PAA by reversed-phase liquid chromatography. The introductionof C18 groups certainlyps certainly enlarged the hydrophobicity of the sorbent as a result of increasenlarged the hydrophobicity of the sorbent as a result of increasing the capacity factor ( k' ) of Pen G. The mixture of Pen G, 6-APA and PAA could notbe effectively separated owing to a low specific surface area of the particles i.e., a low total capacity of the column. On the other hand, particles boundwith amino groups as the sorbent could completely adsorb these antibodies. The elution conditions for adsorbed antibodies need to be further investigated.
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Ke, Cheng-Ho, and 柯成河. "Preparation and application of porous poly(styrene-divinylbenzene) beads for enzyme immobilization." Thesis, 1999. http://ndltd.ncl.edu.tw/handle/34418445839209639118.
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碩士國立中正大學
化學工程研究所
87
Highly porous and cross-linked styrene-divinylbenzene copolymer (PS-DVB) particles have been widely used as the stationary phases for size exclusion and ion-exchange chromatography. For biological applications, for example, protein chromatography and enzyme immobilization, the porous structure of the particles could lead to diffusional limitation. In this study, the PS-DVB particles having a porous structure with large pores near the periphery of the particles were prepared for biological applications. Styrene-divinylbenzene copolymer particles were prepared via a method of multi-step swelling and polymerization in this research. The influences of the amount of styrene used for preparing polymeric porogen particles and toluene used for copolymerization on the particle morphology and porous structure were studied. The prepared PS-DVB particles then were used for immobilization of Candida rugosa lipase. The thermostability of resultant immobilized lipase in organic solvent was also studied. Increasing the amounts of the styrene and toluene, respectively, used for preparing polymeric porogen particles and copolymer could result in copolymer particles having a higher specific surface area and uniform size distribution, according to the results from Micromeritics (ASAP 2000) and the photographs of SEM. When C. rugosa lipase was immobilized on PS-DVB, the optimum temperature for enzymatic activity was increased and thermodeactivation in organic solvent was slowed down. However, in comparison with that immobilized on PP, the immobilized enzyme on PS-DVB retained a lower activity after the first stage deactivation due to a probable change in the conformation of enzyme molecule by immobilization.
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Cheng, Yi-Jie, and 鄭亦傑. "Investigation of the Novel Divinylbenzene−Alkyl methacrylate Copolymer as Stationary Phase in Chromatography." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/74335110717736708822.
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博士中原大學
化學研究所
100
Abstract Several novel divinylbenzene(DVB)-alkyl methacrylate (AMA) copolymers were developed as stationary phases in capillary electrochromatography(CEC) and nano-liquid chromatography (nano-LC). In the first part of this study, several poly(S-DVB-LMA) monolithic columns were developed as CEC stationary phases for the analysis of five synthetic antioxidants. Polymerization procedures were optimized by vaying the reaction time, reaction temperature, and LMA-styrene ratio. These monoliths were characterized by examining their SEM images, IR spectra, surface area, pore size, conversion yield, and thermal decomposition temperature. Results showed that the LMA-styrene ratio had the most significant influence on analyte peak symmetry. This also showed that the use of LMA monomer, instead styrene monomer, can improve the peak symmetry and shorten the separation time of the five synthetic antioxidants. This study demonstrates the potentiality of poly(S-DVB-LMA) monoliths as stationary phases, because of high thermal stability and good column reproducibility. In addition, a series of poly(DVB-AMA) monolithic columns, which were prepared by in situ polymerization of DVB and various AMA(butyl-, octyl, and lauryl-methacrylate, in same amount), were developed as CEC separation columns for benzophenone compounds. The benzene moieties in benzophenone compounds interact with the long and flexible alkyl group on the surface of the stationary phase. Results indicated that with an increase in the molecular length of the AMA (e.g. LMA), the polymeric monolith with higher hydrophobicity, can effectively reduce the peak tailing problem of benzophenones, however, a weaker retention was observed. This unusual phenomenon was likely due to the π−π interaction between the aromatic compound and the stationary phase. Using longer alkyl methacrylates as reaction monomer limited the retention of aromatic compounds on the stationary phase surface, thus the π−π interaction between them was possibly reduced. In comparison to the first part, this study demonstrated that the peak tailing problem could also be improved by the inclusion of long alkyl methacrylates to poly(DVB-AMA) columns. In the third part, a series of poly(DVB-AMA) monolithic columns were developed as separation columns of nine common non-steroidal antiinflammatory drugs (NSAIDs) and nine common sulfonamide antibiotics for on-line concentration capillary electrochromatography coupled to mass spectrometry (MS). Results indicated than an on-line concentration step of step-gradient elution combined to this CEC system, and optimizing the difference in eluent strength between the sample matrix and mobile phase, improved the detection sensitivity of all NSAIDs and sulfonamide antibiotics (0.01–0.19g/L for NSAIDs, 0.01–0.14 g/L for sulfonamide antibiotics). Moreover, a simple polishing was done to reduce the roughness of the column end which resulted to a great improvement in the signal stability. The relative standard deviations (RSDs) of the peak areas for the unpolished and polished ends of the poly(DVB-OMA) columns (n = 5) were in the range of 46.1–60.2% and 8.9–16.4%, respectively. For the final part of this study, the potential of poly(DVB-SMA) monoliths as separation columns for the six polycyclic aromatic compounds and peptide digests in nano-LC coupled with UV or MS was evaluated. For the six polycyclic aromatic compounds, this study proved once again that the peak tailing problem can be reduced by decreasing the benzene moieties on the stationary phase (even in an LC system where EOF is absent). The van Deemter curve indicates that the poly(DVB-SMA) column had high efficiency at high linear flow rate. This monolith, with a peak capacity of 424, successfully identified the tryptic digested BSA peptides using nano-LC−MS/MS with a 70-cm long column. In total, 46 peptides were identified with sequence coverage of 73%.
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Ping-Wen, Yen, and 顏炳文. "Temperature Programmed Reduction and Oxidation of Metal Acetate on Styrene-divinylbenzene Copolymer Support." Thesis, 2000. http://ndltd.ncl.edu.tw/handle/07857205093235272298.
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博士國立成功大學
化學工程學系
88
Palladium acetate was added in alcohol solution including methanol to hexanol. The reduction of palladium acetate to palladium was found at room temperature and atmosphere. When the alcohol was vaporized, palladium was deposited on glass, -Al2O3 or styrene-divinylbenzene (SDB) copolymer support and formed a thin film of palladium or palladium acetate. The palladium acetate was dissolved in methanol solution and shook in an oscillator in the preparation of this type of catalyst, the palladium acetate was simultaneously reduced by methanol and palladium black was formed. The results indicate that the palladium acetate can be dissolved in methanol in a closed system, and palladium black is also obtained. It indicated that the palladium acetate was not major decomposed by sunlight. The residue solution was analyzed with GC/MS, methanol, methyl acetate, dimethoxy-methane were found. These deposited solid particles were dried and analyzed with XRD, the results indicated that the particles were palladium black. Palladium acetate was used as a precursor to prepare the palladium on styrene divinylbenzene copolymer support in methanol at room temperature. The methanol was used for both solvent and reductant. The palladium acetate was reduced to palladium and deposited on SDB which was dipped in methanol. It is a new technique to prepare a polymer-supported Pd catalyst at low temperature. The polymer supports are not decomposed or degraded at room temperature and atmosphere pressure. On the other hand, in the conventional method for preparing catalyst, calcination and reduction at high temperature were the necessary steps which could not apply to the polymer support, since the polymer support would be slowly decomposed at high temperature. The TPR and FTIR results showed that the amount of palladium acetate adsorbed on SDB copolymer increased with the loading of palladium acetate in the solution when the palladium on SDB copolymer was below 0.6 wt% and decreased with the loading of palladium acetate when the loading of palladium on SDB copolymer was higher than 0.6 wt%. The results also showed that a maximum palladium acetate concentration on SDB copolymer was 0.6 wt%. When the loading of palladium on SDB was over 1.0 wt%, the palladium acetate was almost reduced to palladium in the presence of methanol. The advantages of this new technique are: one may prepare an active palladium supported on hydrophobic polymer at low temperature and the polymer supports are not destroyed or decomposed. Furthermore, most of the palladium acetate on SDB copolymer support was reduced to palladium by methanol. This new technique is much better than conventional methods for preparing catalyst using polymer support. The catalyst using hydrophobic polymer supports are good for oxidation processes which, in general, generate water. And the generated water is easily adsorbed on an inorganic support and poison the catalyst. To understand the catalytic oxidation process, the adsorption and desorption of oxygen on a catalyst is a key step. Palladium acetate was used as a precursor to prepare palladium catalyst on different supports. The oxygen adsorption and desorption of the prepared palladium catalyst were explored by using of temperature programmed oxidation. The results revealed that the characteristics of oxygen adsorption on palladium on SDB supports were different from that supported on conventional inorganic supports. The results of this study indicated that an unexpected adsorption/desorption phenomenon of oxygen on Pd/SDB was observed. In the temperature programmed oxidation (TPO) test, oxygen was adsorbed at high temperature region of 220~245C and desorbed at lower temperature region of 145 ~ 190C. The oxygen adsorption and desorption were reversible. The tests have been repeated many times for confirmation. The amount of oxygen adsorption increased with the partial pressure of oxygen. It indicates that the forces among oxygen and palladium and SDB copolymer are not chemical bonded that might be a weak physical force. This such phenomenon has been found in inorganic system, there is no such report for metal/polymer system. On the other hand, there was no corresponding oxygen adsorption and desorption phenomena for palladium supported on -Al2O3, SiO2 and Y-zeolite inorganic supports. The amount of oxygen adsorption and desorption on 1 wt% Pd on SDB copolymer was over one mole oxygen per mole palladium, obviously, the oxygen adsorption and desorption cycle is not due to the change of palladium oxide state. The results suggested that the oxygen might be adsorbed on palladium, then diffused into the surface of SDB copolymer. XAD-4, XAD-16 and SDB copolymer which contained aromatic rings which might be served as oxygen receiver. Palladium acetate was easily reduced to palladium by methanol at room temperature, while the copper acetate, cobalt acetate and nickel acetate were not easily reduced by methanol at room temperature. Therefore, The effect of palladium on the reduction of copper acetate, cobalt acetate and nickel acetate on styrene-divinylbenzene copolymer was studied. The results showed that the deposited palladium promoted the reduction of copper, cobalt and nickel ions. The hydrogen was adsorbed by the reduced palladium and migrated to the copper acetate, cobalt acetate and nickel acetate, and then the reducing temperature of copper, cobalt and nickel ion decreased significantly in the presence of palladium. The reduced metal might interact with palladium in the reduction procedure and interfered with the hydrogen adsorption of palladium. Different sequence of impregnating of copper acetate and palladium acetate on SDB in methanol solution was carried out, the amount of hydrogen absorption and the hydrogen reduction pattern were different for different sequence of impregnation. Comparison of the TPR profile of Pd and Cu on SDB catalysts prepared with different impregnating sequence, the largest amount of copper acetate contact with palladium was the catalyst which copper acetate was impregnated on SDB first, then palladium was impregnated and its reducing temperature was the lowest. For the sequence of reducing cobalt acetate-palladium acetate on SDB system, the hydrogen reduction pattern of 1% Pd, and then 1% Co on SDB was different from that of 1% Co, and then 1% Pd on SDB or that of 1% Co and 1% Pd simultaneously on SDB. However, for nickel acetate- palladium acetate impregnated on SDB with different sequence, the hydrogen reduction pattern was similar for different impregnated sequence. The hydrogen desorption heat of Pd/SDB is lower than that of Pd/-Al2O3, therefore, Hydrogen migrates to SDB surface is easy and facilitates the hydrogenation of organic compound. The findings about this type of reduction to produce palladium on hydrophobic catalyst by the cheap methanol or ethanol as reducing agents was used as the oxidation catalyst of organic substance. The findings also create a new technique for electroless plating. It will be widely used in the semiconductor industry. That is potential for the further application of this technique.
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Lin, Jhih-Yun, and 林芷韻. "Poly(styrene-divinylbenzene)/ activated carbon composites for solid-phase microextraction of phthalate esters." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/ugtp45.
Full textAbstract:
碩士中原大學
化學研究所
103
Abstract In this study, two types of polymeric monoliths combined with activated carbon (AC), AC-poly(butyl methacrylate-ethylene dimethacrylate) and AC-poly(styrene-divinylbenzene), were prepared via in-situ polymerization and compared their extraction efficiency for phthalate esters (PAEs). In order to establish the PAEs separation method, Micellar Electrokinetic Chromatography (MEKC) and ultra performance liquid chromatography (UPLC) were utilized for the separation and optimization in the extraction efficiency for PAEs using the fabricated AC-polymeric monoliths. Different parameters affecting the extraction efficiency of two AC-polymeric monoliths for PAEs, such as amount of AC, desorption solvent, desorption volume and ion concentration for sample loading, were investigated. The results for both AC-polymer (62.5 wt.% AC), using an extraction column of 5 cm, borates ion concentration at 55mM and 1.5 mL ACN as the desorption solvent, showed that AC-poly(styrene-DVB) has better extraction recovery for PAEs than AC-poly(BMA-EDMA). It was found that the presence of AC has significant effect in PAEs desorption. Under the optimized condition of AC-poly(styrene-DVB), eight PAEs were extracted at low concentrations (1ppm) with recovery range of 71.6% to 101.4% (<4.7% RSD), good reproducibility and stability. Finally, the fabricated column was applied in water sample.
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"Synthesis and characterization of copolymers based on styrene, divinylbenzene and methyl methacrylate with magnetic properties." Tese, Biblioteca Digital de Teses e Dissertações da UERJ, 2006. http://www.bdtd.uerj.br/tde_busca/arquivo.php?codArquivo=108.
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Chiang, Liang Kun, and 江昆諒. "One pot synthesis of Poly(Ethylene/Styrene/Divinylbenzene) copolymer-graft-Syndiotactic Polystyrene and its applications." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/51320723118826042423.
Full textAbstract:
碩士國立中正大學
化學工程研究所
90
The syntheses of Poly(ethylene/styrene/divinylbenzene)-graft-syndiotactic polystyrene copolymers were carried out by first copolymerization of ethylene, styrene and divinylbenzene with dimethyl (tert-butylamide) (tertamethyl-cyclopentadienyl) titanium dichloride/MAO catalyst (forming a vinyl group containing elastomeric macromer ) followed by grafting copolymerization of styrene by using (pentamethyl-cyclopentadienyl) titanium trimethoxide/MAO catalyst. A one pot polymerization process was used for reducing the MAO consumption since this preparation required the utilization of two different metallocene catalysts. Structural characterizations of the resulting copolymer by NMR, GPC and DSC reveal that the resulting copolymer contains an elstomeric backbone grafted with arms of syndiotactic polystyrene. Thereby, using this new copolymer to improve the low impact strength in sPS was examined.
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Narwark, Oliver [Verfasser]. "Spektroskopische Charakterisierung und Bestimmung der Morphologie von substituierten 1,4-Divinylbenzol-Oligomeren / vorgelegt von Oliver Narwark." 2002. http://d-nb.info/965366758/34.
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Wu, Lin-Tai, and 吳令台. "Analyses of non-steroidal anti-inflammatory drugs by poly(methacrylate-divinylbenzene) monolith microextraction coupled with microemulsion electrokinetic chromatographic separation." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/66534685754977834168.
Full textAbstract:
碩士中原大學
化學研究所
102
In this study, we developed a new monolithic material for polymer monolith microextraction (PMME) that was prepared in the capillary and applied to extract non-steroid anti-inflammatory durgs (NSAIDs) in water solution. Herein microemulsion electrokinetic chromatography (MEEKC) was used to check the extraction efficiency. At first, poly(stearyl methacrylate-divinylbenzene) (poly(SMA-DVB)) monolithic column was employed, and the extracted parameters were optimized that included solvent type, flow rate, column length and composition of extraction column. Then, different alkyl chain length of alkyl methacrylate monomers have been tested and different extracted efficiency was obtained due to their hydrophobic and hydrophilic interaction. Finally poly(lauryl methacrylate- divinylbenzene) (poly(LMA-DVB)) monolithic column was the best PMME material which has higher extraction efficiency (recovery from 73.8% to 99.6%) and lower RSD% (run to run: < 10.7 %, column to column: < 13.5 %).
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Liang, Pei-Zhu, and 梁珮筑. "Determination of Phenolic Acids by Capillary Electrochromatography-Mass Spectrometry Using Cyclodextrin Attached Poly(glycidyl methacrylate-divinylbenzene) Monolith as Stationary Phase." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/04558604005339045273.
Full textAbstract:
碩士中原大學
化學研究所
101
In this study, CD-GMA monomer which was synthesized by glycidyl methacrylate (GMA) and cyclodextrins (CDs) via epoxy functional group of GMA was used to prepare poly(CD-GMAn-co-divinylbenzeze(DVB)) based monolith. This novel monolith was used as stationary phase for eight phenolic acids separation in CEC system. Previous reviews indicated these phenolic acids were not achieved baseline separation owing to their hydrophilic nature. Thus, in this study, we would like to improve thier separation by host-guest complex interaction between analytes and CD as well as increaced the hydrophilic property of stationary phase resulted from the hydroxyl groups on CD structure. In addition to optimize ACN level in the mobile phase, CD-GMA monomers’ types (α-CD-GMA or β-CD-GMA), degrees of substitution of GMA in β-CD structure (β-CD-GMAn, (n=1, 2)) and monolith length were discussed. As the poor limit of detection (LOD) (0.95-14.74mg/L) was obtained in this CEC-UV system, we use poly(β-CD-GMA2-DVB) monolith as the separation column of CEC-MS system and results indicated a great improvement in LOD (0.003-0.052 mg/L). Finally, this technique was applied in real sample, such as grape wine for phenolic acid analytes.