Synthesis Of Modified Conducting Polymers And Study Of Their Water Purification Capability

Abstract

Perpetration, characterization and water purification capability of modified conducting polymers have been described. Synthesis of polyaniline (PANI), polyaniline-silica (PANI-silica), polyani line-stearate (PANI-stearate), polyanil me-sodium dodecyl sulfate (PANI-SDS) and polyaniline-ethylene diamine tetra acetic acid (PAN!-EDTA) were carried out at pH 3.1 and at room temperature in aqueous medium by in situ oxidative chemical polymerization process. These composites have been characterized by a wide range of experimental techniques including density analysis, optical microscopy, infra-red spectroscopy, UV-visible spectroscopy and adsorption capability. Elemental analysis for silica content indicate that the chemically synthesized PANI-silica composite contain as high as about I I % silica in the matrix. At the same time it was seen that only 3.9 % EDTA were impregnated in to the polymer matrix and has been confirmed by the complex metric titration. It was seen that the density of PANI-silica composite is higher than that of the bulk polymer. On the other hand, the densities of PANI-stearate, PANI-SDS and PANI-EDTA are smaller than that of the PANI matrix. Optical microscopic view provided very important and visualized information about the bulk polymer and the synthesized composite materials. The presences of white spots into the composites clearly indicate the incorporation of foreign particles into the polymer matrix. Infra-red spectroscopic studies yield useful qualitative information on PANI, PANI-silica, PANI-stearate, PANI-SDS and PANI-EDTA composites. From the spectra, the band characteristics of PANI and other PANI based composite materials confirm the formation of the respective polymer and the composites. !R spectra observed for the studied sample exhibited the appropriate adsorption bands those are attributable to both polymer and the composite component. Typical DTA and TGA analysis for the bulk PANI, PANI-silica, PANI-stearate, PAN!- SDS and PANI-EDTA composite materials provide the useful information about the formation composites and the characteristic thermal properties. Both from the DTA and TGA analyses it was seen that bulk PAN! and composite materials have strong affinity to water molecules, i.e., moisture that was about 40% of the total mass. Distinguishable weight loss at different phases with temperature shown in TGA clearly ascribable to the formation of composite materials. DTA also give the comparable data in favour of formation of composites and also the probable reaction involve in the experiment. Surface area measurements show that the PANI-silica composite have much higher than that of the bulk polymer. The incorporation of fine silica particles into the polymer might lead to this increased surface area. Adsorption of Mn2 and As3+ons on the PANI-silica matrix has been found to occur. At the same time PANl-stearate and PANI-SDS composite materials could be used as the trap for the Mn2 and As3 ions present in the water sample. On the other hand PANI- EDTA composite could adsorb only Mn2 ion from aqueous medium