The objective of this work was to obtain the physico-chemical characteristics and evaluate the degradation of polymeric composites produced from fiber obtained from the babassu palm tree (Attalea speciosa). Babassu stem fibers treated by mercerization were used to obtain the composites. The obtained fiber was used for the preparation of polymer composites in proportions of 5%, 10%, and 20% in a high-density polyethylene matrix. Polymeric composites, were characterized by FTIR, XRD, TG/ DTG, SEM, AC impedance and traction test. Traction tests revealed that at a high fiber concentration of 20%, the mechanical resistance of the composites can decrease. After characterization, the materials were subjected to degradation processes via UV radiation. For comparison, a sample of an oxo-biodegradable plastic bag was evaluated under the same conditions. The incorporation of babassu fiber into an HDPE matrix in the formation of a polymeric composite is promising for enhancing photo-oxidation degradation.
Neste trabalho foi proposta a caracterização química da fibra retirada a partir do caule da palmeira de babaçu. Estudos sobre o efeito do tratamento químico superficial e do teor dos principais componentes químicos presentes também foram realizados. Após a obtenção da fibra de babaçu na forma natural e mercerizada, as amostras foram submetidas às análises de FTIR, SEM, XDR e TG/DTG . Os resultados mostraram a eficiência do processo de tratamento químico superficial utilizado, revelando que a fibra de babaçu apresentou uma melhor propriedade físico-química. A remoção parcial dos componentes amorfos contribuiu para o melhoramento das propriedades mecânica e térmica. Após o processo de extração dos principais componentes lignocelulósico, a fibra de babaçu também revelou uma alta porcentagem de material cristalino em sua composição.
This work reports the development of an electrochemical biosensor after immobilization of the lymphocytes to detect the reaction between antibodies and specific HLA antigens present in the serum samples. A clean homemade gold electrode with voltammetric polycrystalline characteristics was used. Lymphocytes were immobilized and tested with positive and negative human serum and complements on the gold electrode. The experiments were carried out in a cell with three electrodes: working - gold, and reference - Ag/AgCl/sat. KCl and auxiliary - platinum. The cyclic voltammetric analyses of immobilized lymphocytes on the gold surface presented an anodic current equal to 1.78 μA at c.a. 0.50 V vs. Ag/AgCl/sat. KCl. The electrochemical responses of the serum (positive and negative) and complement do not show signs of oxidation or reduction in the potential range used. The electrodes with cells and positive serum showed the amplified current signal in the oxidation potential of the cells. The electrode was developed to verify the antigen-antibody reaction, present lymphocyte cells, and human serum samples. The electrode was qualitatively efficient when compared to the methods of flow cytometric analysis and complement-dependent cytotoxicity, being able to be used with operational and economic advantages.
This work reports the development of an electrochemical biosensor after immobilization of the lymphocytes to detect the reaction between antibodies and specific HLA antigens present in the serum samples. A clean homemade gold electrode with voltammetric polycrystalline characteristics was used. Lymphocytes were immobilized and tested with positive and negative human serum and complements on the gold electrode. The experiments were carried out in a cell with three electrodes: working - gold, reference - Ag/AgCl/sat. KCl and auxiliary - platinum. The cyclic voltammetric analyses of immobilized lymphocytes on the gold surface presented anodic current equal to 1.78 μA at c.a. 0.50 V vs. Ag/AgCl/sat. KCl. The electrochemical responses of the serum (positive and negative) and complement do not show signs of oxidation or reduction in the potential range used. The electrodes with cells and positive serum showed the amplified current signal in the oxidation potential of the cells. The electrode was developed to verify the antigen antibody reaction, present lymphocyte cell and human serum samples. The electrode was qualitatively efficient when compared to the methods of flow cytometric analysis and complement dependent cytotoxicity, being able to be used with operational and economic advantages.
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