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Previous issue date: 2012-03-30 / Dynamic light scattering was used to monitor relaxation processes in chitosan
solutions at concentrations within the semi-dilute and concentrated regimes,
Kowhlrausch-Williams-Watts (KWW) equation being successfully fitted to intensity
correlation function data. The dependence of KWW equation parameters on chitosan
concentration indicated that an increase in concentration from semi-dilute to
concentrated regimes resulted in narrowing the distribution of relaxation rates;
temperature dependence indicated the relaxation process as described as an energy
activated process, whose parameters were function of the interaction between chitosan
chains (enthalpy of activation) and rigidity of chitosan conformations (pre-exponential
factor) / O espalhamento din?mico de luz foi utilizado para monitorar processos de
relaxa??es em solu??es de quitosana em concentra??es dentro dos regimes semidilu?das
e concentradas, a equa??o Kowhlrausch-Williams-Watts (KWW) foi ajustada com ?xito
para os dados de intensidade de fun??o de correla??o. A depend?ncia dos par?metros da
equa??o KWW sobre a concentra??o de quitosana indicam que um aumento na
concentra??o de semidilu?da ? concentrada resultou no estreitamento da distribui??o das
taxas de relaxa??o; a depend?ncia da temperatura indicada no processo de relaxa??o, foi
descrito como energia de ativa??o do processo, cujos par?metros foram fun??es da
intera??o entre as cadeias de quitosana (entalpia de ativa??o) e rigidez das
conforma??es de quitosana (fator pr?-exponencial)
| Identifer | oai:union.ndltd.org:IBICT/oai:repositorio.ufrn.br:123456789/17662 |
| Date | 30 March 2012 |
| Creators | Oliveira, Victor Anderson Ver?ssimo de |
| Contributors | CPF:90623207753, http://lattes.cnpq.br/8143800826985556, Wanderley Neto, Alcides de Oliveira, CPF:00738841463, http://lattes.cnpq.br/4789528535524269, Rossi, C?tia Guaraciara Fernandes Teixeira, CPF:77044568491, http://lattes.cnpq.br/0103853142184734, Sousa, Emanuel Alves de, CPF:00823037460, http://lattes.cnpq.br/8566005165321301, 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/masterThesis |
| 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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