Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-08-09T22:44:46Z No. of bitstreams: 1 JessicaSouzaMarques_TESE.pdf: 2267676 bytes, checksum: f71e2156c17464c73f99c0aec00ef206 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-08-10T22:44:23Z (GMT) No. of bitstreams: 1 JessicaSouzaMarques_TESE.pdf: 2267676 bytes, checksum: f71e2156c17464c73f99c0aec00ef206 (MD5) / Made available in DSpace on 2016-08-10T22:44:23Z (GMT). No. of bitstreams: 1 JessicaSouzaMarques_TESE.pdf: 2267676 bytes, checksum: f71e2156c17464c73f99c0aec00ef206 (MD5) Previous issue date: 2015-12-14 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico (CNPq) / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / Neste trabalho foram produzidas membranas de quitosana reticuladas ionicamente, utilizando o ?cido sulf?rico como agente de reticula??o para serem aplicadas no tratamento de ?guas residuais da ind?stria do petr?leo. Duas metodologias de reticula??o das membranas foram desenvolvidas: homog?nea e heterog?nea. No processo homog?neo a vari?vel analisada foi a raz?o molar de SO42-/ NH3+ (1:6 e 1:4), enquanto, no processo heterog?neo o tempo de imers?o das membranas em ?cido sulf?rico foi a vari?vel em estudo, sendo utilizado tempos de 5 e 30 minutos. Os resultados de FTIR-ATR evidenciaram a forma??o de liga??es i?nicas entre os grupos NH3+protonados da quitosana e os ?ons sulfato do agente reticulante. Apenasnas membranas heterog?neas indicando um grau de reticula??o bastante pequeno para as homog?neas.As an?lises de TG/DTG e DRX confirmaram a forma??o dessas intera??es, como tamb?m demonstraram que houve a forma??o de uma nova estrutura na regi?o superficial das membranas CS5 e CS30 em rela??o ?s membranas de CS, CS16 e CS14. Os ensaios de intumescimento em meio aquoso evidenciaram que os processos de reticula??o reduziram a capacidade de sor??o das membranas. Enquanto que em meio ?cido as membranas de CS16 e CS14 aumentaram a capacidade de sor??o at? um percentual m?ximo de aproximadamente 140%, e as de CS5 e CS30 atingiram um m?ximo de 60%. As propriedades mec?nicas indicaram o comportamento r?gido e d?ctil das membranas reticuladas. Atrav?s dos experimentos de sor??o de solu??o de CuCl2, foi determinado que o m?ximo de efici?ncia foi obtido para as membranas CS16 com 73% de remo??o de cobre em pH 5,0 e 87% em pH 4,0. Os experimentos realizados com CuSO4 tamb?m resultaram em 80% de remo??o de ?ons de Cu2+ para as membranas de CS16. Tamb?m foi verificado que o aumento da concentra??o e da temperatura refletiram na diminui??o da capacidade de adsor??o para todas as membranas. Os resultados de cin?tica evidenciaram que as membranas foram melhor caracterizadas pela equa??o de pseudo-segunda-ordem. E, osEstudos de equil?brio demonstraram que as membranas de CS, CS16 e CS14 seguem o modelo de Langmuir, enquanto que as membranas de CS5 e CS30 seguem o modelo de Freundlich. Os experimentos de filtra??o resultaram em m?ximo de reten??o de ?ons de Cu2+ para as membranas de CS16 e CS5, atingindo 92 e 98% respectivamente. / In this work a chitosan (CS) ionically crosslinked were manufactured by treatment with sulfuric acid solution for application in the treatment of wastewater from oil industry. Two crosslinking process were developed: homogeneous and heterogeneous. In the homogeneous process the ratio molar of SO42-/ NH3+ (1:6 and 1:4) were the variable analyzed, denominated CS16 and CS14 respectively. In the heterogeneous process the soaking time of the membranes in sulfuric acid solution were the variable studied, being used times of 5 (CS5) and 30 (CS30) minutes. FTIR-ATR results indicated no changes in the characteristics of chitosan after homogeneous crosslinking process, while heterogeneous crosslinking showed formation of ionic bonds between protonated groups from chitosan and the crosslinking agent sulfate ions. TG/DTG and XRD analysis confirmed the formation of these interactions, as also shown the new structure on the surface region of CS5 and CS30 membranes compared to CS, CS16 e CS14. Swelling test in aqueous medium have shown that crosslinking process reduced the membrane sorption capacity. Swelling test in acid medium demonstrated that CS16 and CS14 membranes increasing the adsorption capacity up to a maximum percentage of 140% approximately, whereas the CS5 e CS30 reached a maximum of 60%. The mechanical properties indicated the stiff and ductile behavior of crosslinked membrane. Adsorption experiments of CuCl2 results that CS16 membranes reached the efficiency maximum with 73% of copper removal at pH 5.0 and 87% at pH 4.0. The experiments with CuSO4 also obtained efficiency maximum to the CS16 membrane and 80% to the removal of Cu2+ ions. Also was verified that the increase of concentration and temperature cause a decrease in the adsorption capacity for all membranes. Kinetics study indicated that pseudo-second-order obtained characterized better the membranes. Equilibrium studies demonstrated that the CS, CS16 and CS14 follow the Langmuir model, whereas CS5 and CS30 follows Freundlich model. Filtration experiments results with rejection maximum to the CS16 and CS5 membranes, reaching 92 and 98% respectively.

Made available in DSpace on 2014-12-17T15:41:41Z (GMT). No. of bitstreams: 1 GuymmannCS.pdf: 1754712 bytes, checksum: 731ccc6c9bb4f783f3a118094959297b (MD5) Previous issue date: 2008-02-29 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Latices based on acrylic acid and ethyl methacrylate, crosslinked with 1,6‐propoxylate‐hexanodiol diacrylate were synthesized via emulsion polymerization with different monomeric compositions. The resultant latices were thickened with different NaOH/(acrylic acid) molar ratios and were characterized by titrimetry, zeta potential measurements, turbidimetry, and capillary viscometry. Intrinsic viscosity was determined for an uncrosslinked copolymer, using toluene as solvent. All the latices were coagulated with NaCl and washed with water at 60?C analyzed by FTIR spectrophotometry, in order to characterize functional groups from the copolymer and crosslinking agent. / L?tices ? base de ?cido acr?lico e metacrilato de etila, reticulados com 1,6‐diacrilato de propoxilato hexanodiol, foram sintetizados via polimeriza??o em emuls?o, com diferentes composi??es monom?ricas. Os l?tices sintetizados foram espessados com diferentes raz?es molares NaOH/(?cido acr?lico) e caracterizados por titrimetria, medidas de potencial zeta, turbidimetria e viscometria capilar. Todos os l?tices foram coagulados com NaCl, lavados com ?gua destilada e em seguida secos a 60 0C, para a an?lise de FTIR. A viscosidade intr?nseca do l?tex n?o reticulado foi determinada utilizando tolueno como solvente. O potencial zeta foi usado para determinar a carga superficial das part?culas e o FTIR para caracterizar os grupos funcionais dos comon?meros.

Made available in DSpace on 2014-12-17T15:01:17Z (GMT). No. of bitstreams: 1 BentoPCN.pdf: 1568863 bytes, checksum: bd484a66a36dd1be9ccc75015b40e5e8 (MD5) Previous issue date: 2009-03-05 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / Currently, studies in the area of polymeric microcapsules and nanocapsules and controlled release are considerably advanced. This work aims the study and development of microcapsules and nanocapsules from Chitosan/MDI, using a new technique of interfacial polycondensation combined to spontaneous emulsification, for encapsulation of BZ-3. It was firstly elaborated an experimental design of 23 of the particle in white without the presence of BZ-3 and Miglyol, where the variables were the concentrations of MDI, chitosan and solvent. Starting from the data supplied by the experimental design was chosen the experiment with smaller particle diameter and only added like this BZ-3 and Miglyol. The suspension containing concentrations of 6.25 mg/mL, 12.5 mg/mL, 18.75 mg/mL, 25 mg/mL of BZ-3 were prepared, nevertheless, during the storage time, these formulations presented drug precipitates in the suspensions of 18.75 mg/mL and 25 mg/mL of BZ-3. This apparition of precipitate was attributed to the diffusion of BZ-3 for the aqueous phase without any encapsulation, suggesting so the use of the smaller concentrations of the BZ-3. The suspension containing 6.25mg/mL of BZ3 presented average size of 1.47μm, zeta potential of 61 mV, pH 5.64 and this sample showed an amount of BZ-3 and drug entrapment of 100 %. The suspension containing 12.5mg/mL of BZ-3 presented average size of 1.76μm, zeta potential of 47.4 mV, pH 5.71 and this sample showed an amount of BZ-3 and drug entrapment of 100 %. Then, showing such important characteristics, these two formulations were chosen for futher continuity to the study. These formulations were also characterized by the morphology, FTIR, stability for Turbiscan, DSC and a study of controlled release of the BZ-3 was elaborated in different receiving means / O presente trabalho visou o estudo e desenvolvimento de um sistema micro e nanoestruturado de quitosana reticulada por diisocianato, pela t?cnica de policondensa??o interfacial combinada com emulsifica??o espont?nea, para encapsula??o de benzofenona-3 (BZ-3), um filtro solar qu?mico. Foi elaborado primeiramente um planejamento experimental de 23 para desenvolvimento da formula??o de part?culas de quitosana e MDI (4,4 -difenil metano diisocianato), onde as vari?veis foram ?s concentra??es de MDI, de quitosana e do solvente. A partir dos dados fornecidos pelo planejamento experimental, optou-se pelas condi??es de processo e formula??o capazes de gerar o menor di?metro de part?cula. O estudo prosseguiu com a incorpora??o de BZ-3 e Miglyol (n?cleo das c?psulas formadas). Suspens?es de nanoc?psulas com concentra??es de 6,25 mg/mL, 12,5 mg/mL, 18,75 mg/mL e 25 mg/mL de BZ-3 foram preparadas, por?m durante o per?odo de armazenamento ocorreu o aparecimento de precipitados cristalinos, nas suspens?es de 18,75 mg/mL e 25 mg/mL de BZ-3. Este aparecimento de precipitados cristalinos foi atribu?do ? difus?o da BZ-3 para a fase aquosa n?o ocorrendo sua encapsula??o. A suspens?o contendo 6,25 mg/mL de BZ-3 apresentou di?metro m?dio de 1,47μm, potencial zeta de 61 mV, pH de 5,64 e teor de encapsula??o pr?ximos a 100 %. A suspens?o contendo 12,5mg/mL de BZ-3 apresentou di?metro m?dio de 1,76μm, potencial zeta de 47,4mV, pH 5,71 e teor de encapsula??o pr?ximos a 100 % e foi selecionada juntamente com a de 6,25 mg/mL para a continuidade do estudo. Estas formula??es foram caracterizadas tamb?m pela morfologia, turbidimetria, espectroscopia de absor??o na regi?o do infravermelho, DSC e foi elaborado um estudo de libera??o controlada do f?rmaco em diferentes meios receptores. Em conclus?o, o conjunto dos resultados obtidos demonstra que estas formula??es s?o sistemas promissores para a aplica??o cut?nea de filtros solares

Made available in DSpace on 2014-12-17T14:13:33Z (GMT). No. of bitstreams: 1 ElquioEO_TESE.pdf: 1649953 bytes, checksum: 1098cd34b1d3e6c9a180949d25fa8185 (MD5) Previous issue date: 2010-06-07 / Universidade Federal do Rio Grande do Norte / The aim of this work was to perform the extraction and characterization of xylan from corn cobs and prepare xylan-based microcapsules. For that purpose, an alkaline extraction of xylan was carried out followed by the polymer characterization regarding its technological properties, such as angle of repose, Hausner factor, density, compressibility and compactability. Also, a low-cost and rapid analytical procedure to identify xylan by means of infrared spectroscopy was studied. Xylan was characterized as a yellowish fine powder with low density and poor flow properties. After the extraction and characterization of the polymer, xylan-based microcapsules were prepared by means of interfacial crosslinking polymerization and their characterization was performed in order to obtain gastroresistant multiparticulate systems. This work involved the most suitable parameters of the preparation of microcapsules as well as the study of the process, scale-up methodology and biological analysis. Magnetic nanoparticles were used as a model system to be encapsulated by the xylan microcapsules. According to the results, xylan-based microcapsules were shown to be resistant to several conditions found along the gastrointestinal tract and they were able to avoid the early degradation of the magnetic nanoparticles / O presente trabalho teve como objetivo a extra??o e caracteriza??o do pol?mero de xilana a partir de res?duos de sabugo de milho e a produ??o de microc?psulas a partir deste pol?mero. O primeiro passo foi a extra??o da xilana em meio alcalino e caracteriza??o deste pol?mero quanto as suas propriedades tecnol?gicas (?ngulo de repouso, fator de Hausner, densidade, compressibilidade e compactabilidade), bem como a elabora??o de uma procedimento r?pido e barato para a identifica??o deste pol?mero atrav?s de espectroscopia de absor??o na regi?o do infravermelho. O pol?mero de xilana foi caracterizado como sendo um p? de cor amarelada de baixa densidade e com propriedades de escoamento pouco favor?veis. Ap?s a obten??o e caracteriza??o do pol?mero, microc?psulas de xilana foram preparadas atrav?s da reticula??o polim?rica interfacial e caracterizadas a fim de se obter sistemas multiparticulados gastroresistentes. O trabalho foi delineado buscando-se os melhores fatores na t?cnica de prepara??o das microc?psulas, assim como o estudo do processo, aumento de escala e avalia??o biol?gica. Nanopart?culas magn?ticas foram utilizadas como sistema modelo a ser encapsulado pelas microc?psulas ? base de xilana. Os resultados obtidos demonstraram que as microc?psulas de xilana s?o resistentes ?s diversas condi??es encontradas ao longo do trato gastrintestinal e foram capazes de evitar a degrada??o pr?via das nanopart?culas magn?ticas in vitro

Made available in DSpace on 2014-12-17T14:16:25Z (GMT). No. of bitstreams: 1 AcariliaES_Dissert_01.pdf: 1640327 bytes, checksum: 9c4568aff953d538d26000691eb0407d (MD5) Previous issue date: 2009-03-10 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / Colon-specific drug delivery systems have attracted increasing attention from the pharmaceutical industry due to their ability of treating intestinal bowel diseases (IBD), which represent a public health problem in several countries. In spite of being considered a quite effective molecule for the treatment of IBD, mesalazine (5-ASA) is rapidly absorbed in the upper gastrointestinal tract and its systemic absorption leads to risks of adverse effects. The aim of this work was to develop a microparticulate system based on xylan and Eudragit? S- 100 (ES100) for colon-specific delivery of 5-ASA and evaluate the interaction between the polymers present in the systems. Additionaly, the physicochemical and rheological properties of xylan were also evaluated. Initially, xylan was extracted from corn cobs and characterized regarding the yield and rheological properties. Afterwards, 10 formulations were prepared in different xylan and ES100 weight ratios by spray-drying the polymer solutions in 0.6N NaOH and phosphate buffer pH 7.4. In addition, 3 formulations consisting of xylan microcapsules were produced by interfacial cross-linking polymerization and coated by ES100 by means of spray-drying in different polymer weight ratios of xylan and ES100. The microparticles were characterized regarding yield, morphology, homogeneity, visual aspect, crystallinity and thermal behavior. The polymer interaction was investigated by infrared spectroscopy. The extracted xylan was presented as a very fine and yellowish powder, with mean particle size smaller than 40μm. Regarding the rheological properties of xylan, they demonstrated that this polymer has a poor flow, low density and high cohesiveness. The microparticles obtained were shown to be spherical and aggregates could not be observed. They were found to present amorphous structure and have a very high thermal stability. The yield varied according to the polymer ratios. Moreover, it was confirmed that the interaction between xylan and ES100 occurs only by means of physical aggregation / Sistemas c?lon-espec?ficos t?m atra?do o interesse da ind?stria farmac?utica devido ? possibilidade de tratarem enfermidades, como as doen?as inflamat?rias intestinais (DII), que compreendem um problema de sa?de p?blica em muitos pa?ses. Apesar de ser considerada uma mol?cula bastante eficiente para o tratamento das DII, a mesalazina (5-ASA) ? rapidamente absorvida no trato gastrintestinal superior e sua absor??o sist?mica leva ? incid?ncia de s?rios efeitos adversos. Este trabalho teve como objetivos produzir um sistema polim?rico microparticulado ? base de xilana e Eudragit? S-100 (ES100) para libera??o c?lon-espec?fica de 5-ASA e avaliar a intera??o entre os pol?meros constituintes do sistema, al?m de aprofundar a caracteriza??o f?sico-qu?mica e tecnol?gica da xilana. A xilana foi extra?da a partir de sabugos de milho e caracterizada quanto ao rendimento, granulometria, cristalinidade, propriedades reol?gicas e comportamento t?rmico. Em seguida, 10 formula??es contendo 5-ASA foram preparadas em diferentes propor??es de xilana e ES100 atrav?s da secagem por aspers?o das solu??es polim?ricas com NaOH 0,6N ou tamp?o-fosfato pH 7,4, como solvente. Al?m disso, 3 formula??es constitu?das de microc?psulas de xilana produzidas por reticula??o polim?rica interfacial foram revestidas por ES100 atrav?s de secagem por aspers?o em diferentes propor??es polim?ricas e empregando-se NaOH 0,6N ou tamp?o-fosfato pH 7,4, como solvente. As micropart?culas foram avaliadas quanto ao rendimento, morfologia, granulometria, homogeneidade, aspecto visual, cristalinidade e comportamento t?rmico. A intera??o entre os pol?meros foi investigada atrav?s da espectroscopia na regi?o do infravermelho e de an?lises t?rmicas. A xilana extra?da apresentou-se como um p? muito fino, com tamanho m?dio inferior a 40μm, e com colora??o opaca levemente amarelada. A avalia??o das propriedades reol?gicas da xilana permitiram a caracteriza??o desse pol?mero, em seu estado original de p?, como um material de baixa densidade, fluxo restrito e bastante coesivo. Foram obtidas micropart?culas esf?ricas e sem presen?a de agregados, com estrutura amorfa, em sua maior parte, e bastate est?veis a temperaturas elevadas. Al?m disso, confirmou-se que a intera??o entre xilana e ES100 ocorre apenas por agrega??o f?sica