Radiation Copolymerization of Styrene/Acrylic Acid Grafted to Silica Surface For separation and purification purposes: I. Characterization and sorption of some organic compounds and Metals.

Abstract

Highly porous and interconnected styrene/acrylic-based porous materials were prepared by radiation-induced graft copolymerization of styrene/acrylic acid monomers onto surface of silica prepared from rice husk ash. The influence of synthesis conditions; such as irradiation dose, monomer concentrations and different solvents; were studied. It was found that the nature of the solvent had profound influence on the copolymerization reaction and water /ethanol mixture was selected as a suitable solvent for copolymerization processes. Graft copolymers of styrene/ acrylic onto silica surface was verified through Fourier Transform Infrared (FTIR) spectroscopy and Eenergy Dispersive Spectroscopy (EDX) was used to investigate the surface profile of representative copolymers by viewing the distribution of elemental nitrogen. ThermoGravimetric Analysis (TGA) and differential Thermal Analysis (DTA) of the copolymers were investigated. From the characterization of the prepared copolymer it was found that: copolymers of (styrene/acrylic)/silica are considerably different from each other, (styrene/acrylic)/silica based copolymers exhibited relatively more homogenous surface compared to (styrene/acrylic) copolymers. Water uptake percent increases as silica ratio increases to reach 24174 (mol/gm) and this prepared copolymer has a considerable capacity for adsorption of organic compounds and metals.