Encapsulamento de biopesticida em hidrogéis à base de k-carragena visando a sua liberação gradativa contra larvas de Aedes aegypti

• Autor(a) principal: Nasser, Samir
• Data de Publicação: 2016
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UERJ
• Texto Completo: http://www.bdtd.uerj.br/handle/1/15817
• topic: Aedes aegypti; dengue; Kappa Carrageenan; bacillus thuringiensis israelenses; Biopesticides; Aedes aegypti; dengue; Kappa carragena; bacillus thuringiensis israelenses; biopesticidas; CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA::QUIMICA ORGANICA::POLIMEROS E COLOIDES

The problem of combating Aedes aegypti, which transmits dengue, among other diseases, persistsin Brazilas a whole. For this fight has always used chemical pesticides, andthe main one isthetemephos. From the year 2000, two concernscame into existence: the first samplesof resistantlarvae wereidentified andconcern for theenvironmental impactin relation to theuse of thispesticide, such as killing natural predatorsof the targetinsect.Based on theseproblems, new pesticides have been tested. Among them, one had more prominent because it is a biopesticide Bacillus thuringiensis israelensis (Bti). However, this presents a problem. Its rapid degradation makes it until today, hardly used, becauseit is necessary to new applications in short time and therefore cost increases.This master's project aimed to prepare, characterize and apply hydrogels based Kappa carrageenan containing this biopesticide in order to reduce degradation and combat the larvae of Aedes aegypti. To this end, ways of preparing the hydrogel was evaluated by varying its shape (spherical or pellet), concentration and their crosslinking temperature (KCl) and type of crosslinker (KCl and NaCl). Concluding by the results of scanning electron microscopy (SEM), thermal gravimetric analysis (TGA) and the degree of swelling (GI) that his best preparation occurred as a tablet, and crosslinked by KCl 0.3 mol ∙ L-1 without heating. It was then applied to two preparation methods of this pellet with biopesticide, and used prior art techniques SEM, TGA and GI and also infra red spectra (FTIR) to characterize this material and bioassay tests were made in order to evaluate their efficiency in relation to the lethality of mosquito larvae. The methodology I proved effective after 11 weeks of bioassays, with a mortality rate close to 100% in this period, while the methodology II did not show satisfactory results