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Previous issue date: 2016-08-22 / A agarose ? um pol?mero natural extra?do de algas que possui a propriedade de formar g?is f?sicos, quando retirado calor do sistema. Essa propriedade possui grande aplicabilidade nas ind?strias aliment?cia e farmac?utica, principalmente em an?lises de DNA. Para esse trabalho, foram preparadas solu??es aquosas em concentra??es diferentes de agarose. Medidas de espalhamento din?mico de luz foram feitas, enquanto se alterava a temperatura do sistema, a fim de obter estruturas mais ou menos organizadas das macromol?culas. Para as medidas de espalhamento, a equa??o Kohrausch-William-Watts (KWW) foi ajustada aos dados, de modo a obter a taxa de relaxa??o m?dia do processo. Adicionalmente, foram feitos testes de reologia das amostras, tamb?m com a varia??o da temperatura. Para ambas as t?cnicas, foram feitos ajustes matem?ticos, com a inten??o de estudar a transi??o h?lice-novelo das cadeias polim?ricas no decorrer da altera??o da temperatura, relacionando-as atrav?s do c?lculo da energia de ativa??o aparente do processo. Nas duas abordagens foi constatado que a energia tende a diminuir para solu??es dilu?das e para altas temperaturas. / The agarose is a natural polymer extract from red algae (Rhodophyceae). This polysaccharide can form physical gels when is removed heat from the system. This property has great applicability in the food and pharmaceutical industries, particularly in DNA analysis. For this work we prepared aqueous solutions at different concentrations of agarose. Measures of Dynamic Light Scattering (DLS) were made while the system temperature was altered so as to obtain structures more or less organized of macromolecules. For DLS measurements, the Kohrausch-William-Watts equation (KWW) was fitted to the data to obtain the average of relaxation rate of the process. Additionally rheometry tests were made also with the temperature variation. For both techniques, were made mathematical adjustments with the intention of studying the helix-coil transition of the polymer chains during the temperature change, relating them by calculating the apparent activation energy. In both approaches it was found that energy tends to decrease for dilute solutions and higher temperatures.
| Identifer | oai:union.ndltd.org:IBICT/oai:repositorio.ufrn.br:123456789/22377 |
| Date | 22 August 2016 |
| Creators | Queiroz, Rog?rio Pereira de |
| Contributors | 90623207753, http://lattes.cnpq.br/8143800826985556, Wanderley Neto, Alcides de Oliveira, 00738841463, http://lattes.cnpq.br/4789528535524269, Balaban, Ros?ngela de Carvalho, 65946499734, http://lattes.cnpq.br/7711521318854102, Vasconcelos, Claudio Lopes de, 02963319452, http://lattes.cnpq.br/7657769529479698, Fonseca, Jos? Luis Cardozo |
| Publisher | PROGRAMA DE P?S-GRADUA??O EM QU?MICA, UFRN, Brasil |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/masterThesis |
| 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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