Polímeros de β-ciclodextrina modificada com L-cisteína : síntese, caracterização e incorporação de nanopartículas de TiO2 e prata

Abstract

The interest in developing environmentally friendly procedures for the synthesis of nanoparticles has increased. Knowing that large amounts of organic pollutants are often released into the aquatic environment by the discharge of domestic and industrial effluents, one of the alternatives for the degradation of organic materials in an aquatic environment is photocatalysis, due to its high efficiency, low cost, simplicity of operation and the possibility of obtaining non toxic or less toxic by-products. In this project, beta-cyclodextrin polymers functionalized with L-cysteine and cross-linked with citric acid were synthesized, which were used to incorporate TiO2 and Ag nanoparticles. The characterization techniques employed were Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), transmission electron microscopy (TEM), thermogravimetric analysis (TG) and UV-VIS spectroscopy with diffuse reflectance (UV -DRS). There are small changes in the FTIR spectra and the appearance of broad peaks in the XRD suggest that β-CD was functionalized with L-cysteine. The nanocomposites (polymers and TiO2NP, polymers and TiO2NP/AgNP) showed sponge-like morphology, having several nanoparticles connected from ~2 to 20 nm. Thermogravimetric analysis (TG) demonstrated the degradation curve of each nanocomposite and an improvement in its thermal stability. only ultraviolet light, but the range of visible light may favor photocatalysis process.