Preparation And Application Of Conductive Polymer Composite Materials

considering the pollution of electromagnetic radiation is threat of human life in recent years, polypyrrole-fly ash cenospheres, a novel composite with core-shell structure, was successfully synthesized by using FACs as the hard-template using the methods of silane coupling agent and layer-by-layer self-assembly process. Furthermore, Due to rapid industrialization, contamination of aquatic ecosystem by mercury has become one of the most serious environmental problems around the world. Adsorption has become one of the most widely investigated methods for Hg (Ⅱ) removal because of its fast speed, low initial cost, and easiness of operation. Recently, polyaniline (PAN) has been used as base material for the adsorption of heavy metals directly, and it shows wide applicability in environmental protection. In order to improve its adsorption properties of mercury anions, the method of co-polymerization is conducted to modify PAN, and the adsorption properties of modified-materials were carefully studied. The mechanism of modification and Hg (Ⅱ) adsorption was also discussed. Major research content and results are listed as follows:(1) After fly-ash cenosphere (FACs) were surface modified by aminopropyltriethoxysilane (APS), a novel composite with core-shell structure, was successfully grafted onto the surface of the FACs, resulting in PPY-APS-FACs composites. The structure, morphologies, and thermal stability properties of the as-prepared samples were characterized by SEM, FTIR, XPS and TG In this approach. The results indicate that the silane coupling agent (γ-aminopropyltriethoxy silane, APS) had no effect on the crystalline structure of raw FACs, and it played an important role in bridging FACs and the PPY layer, and thus the loading amount of polypyrrole in PPY-APS-FACs is more than that in PPY-FACs. the PPY-APS-FACs composites possess low density and the thermal stability is significantly improved too.(2) Uniform polypyrrole (PPy) films, of controlled thickness, were successfully synthesized and immobilized on polyelectrolyte (PE) multilayer-assembled fly-ash cenospheres (FACs) using asimple and versatile method. In this approach, FACs were assembled with multilayers of poly (diallyldimethylammonium chloride)(PDDA) and poly (sodium4-styrenesulfonate)(PSS) using a layer-by-layer self-assembly procedure. Based on the results of SEM, FTIR, Zeta Potential and TG, it can be concluded that The surfaces of the PE-deposited FACs (FAC-(PDDA-PSS) n (n=1～12) became more homogeneous as n increased. Their properties were determined mainly by the PE, not by the FAC itself, The PPy loading amount on the FACs of the composites reached plateaus after the PE layer deposition number exceeded six.(3) A novel polyaniline/attapulgite (PANI-ATP) composite was synthesized and investigated for adsorption of Hg (Ⅱ) from aqueous solutions. A chemical oxidation method was employed for polymerization of aniline on the attapulgite template to obtain a significantly enlarged BET surface area of the adsorbent. Associated adsorption mechanism was also investigated by means of electrophoretic mobility (EM) and X-ray photoelectron spectroscopy (XPS) techniques. Due to a specific coordination between mercury and the amine functional groups on the polyaniline molecular chain, the PANI-ATP achieved a maximum mercury adsorption capacity of over800mg g-1. The solution pH values had a major impact on Hg (Ⅱ) adsorption by this adsorbent with optimal removal observed around pH5-9. Kinetic study showed that the Hg (Ⅱ) adsorption by PANI/ATP fitted a pseudo-second-order kinetic model, indicating that the Hg(Ⅱ) adsorption process was predominantly controlled by chemical process. It was also proved that the adsorbed Hg (II) could be effectively desorbed from the PANI-ATP with a solution containing75%acetic acid and1%sulfocarbamide. The adsorption capacity of the regenerated adsorbents could still be maintained at93%by the fifth adsorption-desorption cycle.In conclusion, aniline copolymers have a good potential in the field of Mercury Wastewater Treatment research, and also have broad application prospects.