No abstract

No abstract

Neste trabalho abordou-se a utilização de um resíduo de carcinicultura, a carapaça de camarão, como fonte de quitina, precursor do biopolímero quitosana para o qual diversas aplicações têm sido estudadas e executadas nas mais diversas áreas, incluindo a ambiental, com destaque para o tratamento de efluentes para remoção de metais e corantes, biorremediação, entre outros destinos. Quitina foi preparada por desmineralização e desproteinação química, por métodos que demonstraram eficácia maior que 99%. Foram testados diferentes métodos de desacetilação visando à otimização do processo o que compreende menor geração de resíduos, menor tempo e custo reacional e obtenção de alto grau de desacetilação. Resultados preliminares revelam valores de grau médio de desacetilaçao entre 0 e 79% e apontam parâmetros importantes na etapa de desacetilação que ainda precisam ser variados e avaliados a fim de definir o melhor método, a ser utilizado em ensaios com aumento de escala.

Porous carbon materials such as activated carbons are widely used industrially for the purposes of purification, decolourization, deodorization, and gas storage, among others. Routes for the synthesis of these materials employing templates have increasingly attracted attention due to the ease of manipulating the characteristics of the final product. In the present work, a simple synthesis method was applied for the production of highly porous carbon materials using commercial sugar as the carbon source, Aerosil silica as a template, and deionized water. The synthesis procedure was as follows: (I) Gel formation; (II) carbonization of the gels; (III) removal of the silica template; (IV) activation. The materials were characterized by N2 and CO2 physisorption, Raman spectroscopy, X‐ray diffraction, Fourier‐transform infrared spectroscopy (FTIR), scanning electron microscopy, and thermogravimetric analysis. The aging time had an important influence on the specific area and porosity of the material, with physisorption analysis revealing a high specific area and pore volume. The activation procedures further contributed to significantly increasing the specific area (up to 1158 m2 g−1) and pore volume (up to 1.65 cm3 g−1). The X‐ray diffractograms and Raman spectra identified the formation of semi‐crystalline structures in the material, with the presence of a random distribution of graphite and graphene oxide, in addition to amorphous carbon. FTIR analysis showed the presence of bands corresponding to aromatic groups. The results demonstrated that it was possible to obtain materials with excellent potential for use in different industrial sectors using simple raw materials and a technique that is easy to reproduce.