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Previous issue date: 2007-05-28 / Dispersions composed of polyelectrolyte complexes based on chitosan and poly(methacrylic acid), PMAA, were obtained by the dropping method and template polymerization. The effect of molecular weight of PMAA and ionic strength on the formation of chitosan/poly(methacrylic acid), CS/PMAA, complexes was evaluated using the dropping method. The increase in molecular weight of PMAA inhibited the formation of insoluble complexes, while the increase in ionic strength first favored the formation of the complex followed by inhibiting it at higher concentrations. The polyelectrolyte complexation was strongly dependent on macromolecular dimensions, both in terms of molecular weight and of coil expansion/contraction driven by polyelectrolyte effect. The resultant particles from dropping method and template polymerization were characterized as having regions with different charge densities: chitosan predominating in the core and poly(methacrylic acid) at the surface, the particles being negatively charged, as a consequence. Albumin was adsorbed on templatepolymerized CS/PMAA complexes (after crosslinking with glutardialdehyde) and pH was controlled in order to obtain two conditions: (i) adsorption of positively charged albumin, and (ii) adsorption of albumin at its isoelectric point. Adsorption isotherms and zeta potential measurements showed that albumin adsorption was controlled by hydrogen bonding/van der Waals interactions and that brushlike structures may enhance adsorption of albumin on these particles / Dispers?es formadas a partir de complexos polieletrol?ticos de quitosana e de poli(?cido metacr?lico), PMAA, foram obtidas tanto pelo m?todo de gotejamento, como pelo m?todo de polimeriza??o em molde. O efeito da massa molar do PMAA e da for?a i?nica na forma??o dos complexos de quitosana/poli(?cido metacr?lico), CS/PMAA, foi avaliado usando o m?todo de gotejamento. O aumento da massa molar do PMAA inibiu a forma??o dos complexos insol?veis, enquanto o aumento da for?a i?nica primeiramente favoreceu a forma??o dos complexos, depois a inibiu, em altas concentra??es de eletr?litos de baixa massa molar. A complexa??o dos polieletr?litos foi fortemente dependente das dimens?es macromoleculares, tanto em termos da massa molar quanto do efeito de expans?o/contra??o dos novelos, devido ao efeito polieletrol?tico. As part?culas resultantes tanto do m?todo de gotejamento, como da polimeriza??o em molde foram caracterizadas por apresentarem regi?es com diferentes densidades de carga: a quitosana predominantemente presente na regi?o central e o poli(?cido metacr?lico), na superf?cie, sendo, portanto, as part?culas carregadas negativamente. A albumina foi adsorvida nos complexos de CS/PMAA obtidos por polimeriza??o em molde (depois de sofrerem reticula??o covalente usando glutaralde?do) e o pH foi controlado a fim de se obter duas condi??es: (i) adsor??o de albumina carregada positivamente e (ii) adsor??o de albumina em seu ponto isoel?trico. As isotermas de adsor??o e as medidas de potencial zeta mostraram que a adsor??o da albumina foi controlada por liga??es de hidrog?nio/intera??es de van der Waals e que as estruturas em forma de escova puderam aumentar a adsor??o da albumina nessas part?culas
| Identifer | oai:union.ndltd.org:IBICT/oai:repositorio.ufrn.br:123456789/17800 |
| Date | 28 May 2007 |
| Creators | Vasconcelos, Cl?udio Lopes de |
| Contributors | CPF:90623207753, http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4788562T6, Pereira, M?rcia Rodrigues, CPF:83115951787, http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4788568T8, Fernandes, Nedja Suely, CPF:44420773472, http://lattes.cnpq.br/9563490368583906, Sousa, Emanuel Alves de, CPF:00823037460, http://lattes.cnpq.br/8566005165321301, Viana, Francisco Arnaldo, CPF:42132886415, http://lattes.cnpq.br/9486815520020549, Fonseca, Jos? Luis Cardozo |
| Publisher | Universidade Federal do Rio Grande do Norte, Programa de P?s-Gradua??o em Qu?mica, UFRN, BR, F?sico-Qu?mica; Qu?mica |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/doctoralThesis |
| Format | application/pdf |
| Source | reponame:Repositório Institucional da UFRN, instname:Universidade Federal do Rio Grande do Norte, instacron:UFRN |
| Rights | info:eu-repo/semantics/openAccess |
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