Please use this identifier to cite or link to this item: http://repositorio.unicamp.br/jspui/handle/REPOSIP/321537
Type: DISSERTAÇÃO DIGITAL
Degree Level: Mestrado
Title: Preparação do biovidro 58S por sol-gel e sol-gel acoplado com combustão auto propagada auto propagada : estudos espectroscópicos, preparação de corpos porosos e ensaios in vitro
Title Alternative: Preparation of 58S bioglass using sol-gel and sol-gel coupled with self-propagated combustion : spectroscopic studies, preparation of porous frame and in vitro tests
Author: Bueno, Otto Mao Vargas Machuca, 1981-
Advisor: Bertran, Celso Aparecido, 1951-
Abstract: Resumo: Neste trabalho foi estudado a preparação do biovidro 58S (60mol% SiO2, 36mol%CaO, 4mol%P2O5) por sol-gel e sol-gel acoplado à combustão auto propagada. O biovidro preparado pelo método acoplado apresentou aumento de estabilidade térmica, redução de temperatura para incorporação de cálcio na rede da sílica, ausência de formação de clusters de fosfato de cálcio cristalino e redução de temperatura para eliminação dos compostos voláteis no tratamento térmico. As modificações estruturais durante a formação do biovidro foram estudadas por métodos espectroscópicos. As suspensões foram processadas pelo método ISISA para a formação de corpos de biovidro porosos. Para obter corpos porosos dendríticos com direção definida, no caso da suspensão preparada com o método sol-gel acoplado, as variáveis, viscosidade relativa inicial de congelamento e velocidade de congelamento devem possuir valores de 1200 e na faixa de 1,2< (10-3cm/s)<1,9, respectivamente. E no caso da suspensão preparada com o método sol-gel simples, as variáveis, viscosidade relativa inicial de congelamento e velocidade de congelamento devem de possuir valores de 1300 e na faixa de 0,7< c(10-3cm/s)<1,2, respectivamente. Os estudos de lixiviação mostram que os biovidros preparados com o método sol-gel acoplado apresentam maior capacidade de formação de fosfato de cálcio em menos tempo de lixiviação

Abstract: In the first chapter of this work studied the preparation of 58S bioglass (60mol% SiO2, 36mol%CaO, 4mol%P2O5) by sol-gel and sol-gel coupled to the self-propagated combustion. The bioglass prepared by the sol-gel method coupled to the self-propagated combustion showed increased thermal stability, temperature reduction by calcium incorporation into the silica network, no formation crystalline calcium phosphate clusters and temperature reduction for elimination of volatile compounds heat treatment. Structural charges during the formation of bioglass were studied by spectroscopic methods. In the second chapter of this work the leaching behavior of bioactive glasses prepared by both methods. The leaching kinetics of bioactive glasses prepared by sol-gel method are strongly inhibited with increasing heat treatment, on the contrary, glasses prepared by sol-gel coupled to the self-propagated combustion method is weakly inhibited with increasing heat treatment. Furthermore, bioactive glasses prepared by sol-gel coupled to the self- propagated combustion method showed the ability to form calcium phosphate precipitate in the leaching times smaller, suggesting a higher bioactive capacity. In the third chapter of this work were prepared porous frame from sol-gel suspensions, using ISISA method ("ice-segregation-induced self-assembly") with radial freezing. The ISISA radial freezing method for 58S suspension system provides the formation of porous frame with a defined direction and dendritic nature. The porosity with defined and dendritic nature direction are controlled with the variables: freezing speed ? and initial relative viscosity of freezing. For porous dendritic frame, using the coupled method, variables, initial relative viscosity of freezing and freezing speed must have values of 1200 (u.a.) and in the range of 1.2 < ?(10-3cm/s) <1.9, respectively. For porous dendritic frame using the sol-gel method, variables, initial relative viscosity of freezing and freezing rate should possess values in the range of 1300 (u.a.) and 0.7 < ?(10-3cm/s) <1 2, respectively
Subject: Biovidro 58S
Método sol-gel acoplado à combustão auto propagada
Cinética de lixiviação
Método ISISA
Congelamento radial
Editor: [s.n.]
Date Issue: 2015
Appears in Collections:IQ - Tese e Dissertação

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