Desenvolvimento de um silsesquioxano imidazolico para adsorção de íons metálicos em solução aquosa

Abstract

The present work describes the preparation and characterization of an imidazole functionalized silsesquioxane with the objective of applying as metallic ion adsorptive for environmental interest, using as a synthesis the sol-gel process whose route has been widely used due to the numerous advantages. The first step consisted of the reaction between tetraethylorthosilicate and 3-chloropropyltrimethoxysilane, through the sol-gel process, for the formation of the material designated as TEOS / CPTMS. The incorporation of the imidazole into the silica network was promoted, giving the npropyl imidazole silsesquioxane chloride. The obtained material was found in the techniques of Fourier transform infrared (FTIR), nuclear magnetic resonance spectroscopy (29Si and 13C NMR), X-ray diffractometry (XRD), Ramam scattering spectroscopy, Surface area analysis by Brunauer, Emmett and Taller (BET) isortermas. The material exchange capacity of was 2.87 mmol g-1. Due to its good exchangeability, the material was used in the adsorption of metallic ions, of environmental interest, in aqueous medium. The time to equilibrium in the adsorptiondesorption process of 8 hours, the Cu+2 and Ni+2 ion adsorb better at pH 4, since the adsorption process of the Cd+2 ion apparently does not influence the pH of the medium. The synthesized material adsorbed 3.60 mmol Cu+2, 2.68 mmol Cd+2 and 1.10 mmol Ni+2 per grama of material. The model that obtained the highest agreement with the experimental results was the model of Langmuir compared to the model of Freudlich.