Synthesis and characterization of polyaniline composites with silica gel, styrene-divinyl benzene resin beads, calcium alginate and tetraethoxy silane substrates

Abstract

Initially, Polyaniline (PAni) was synthesized in the powder form by chemical oxidative polymerization of aniline with ammonium persulphate in HCl medium. Further, composites of PAni with beads of silica gel, styrene-divinyl benzene resin beads and calcium alginate were prepared by in-situ chemical polymerization of aniline. Pre-formed base-PAni and tetraethoxysilane were used as precursors for the synthesis of PAni-siloxane composite disks. Ion exchange capacity of PAni powder was found to be 3.25 ± 0.084 meq g−1. PAni powder and its composites were characterized by elemental analysis, UV–visible and FTIR spectroscopy, TG-DSC, SEM, molecular weight and ion exchange capacity measurements. All the composites, except the alginate, were found to be thermally more stable than the powder form of PAni. The composite beads can be applied for future studies in the column mode of operations. Preliminary evaluation of the PAni-siloxane disc for arsenic sorption from aqueous solutions showed promising results. These disks are easy to handle, durable and the sorbed species can be directly quantified, i.e., without post-sorption processing, by energy dispersive X-ray fluorescence spectrometry.