Synthesis Of Lightweight Polyaniline Composite And Adsorption Behavior Research

Among the conductive polymers, polyaniline(PANI) as an adsorbent to remove organic dye has received increasing attention owing to its functional groups such as imine and amine, cost effectiveness, easy synthesis, and excellent environmental stability. Since most of conventional PANI adsorbents are powders and difficult to be separated from aqueous solutions, 3D porous PU and hollow glass microspheres(HGS) decorated with carboxyl-functionalized multi-wall carbon nanotubes(CNTs) were explored as lightweight substrates for polyaniline deposition by in situ polymerization. In this work, lightweight and self-separated PU/CNTs/PANI and HGS/CNTs/PANI composites were prepared as novel composite adsorbents. The structure and property of the composites were characterized by means of FTIR, SEM, XRD, Zeta potential value, XPS, TG and XRD, etc.First, PU/CNTs composites were prepared by ultrasonication of CNTs-COOH and PU. Then PU/CNTs/PANI composites were synthesized by in-situ polymerization of aniline on PU/CNTs. The analysis results of SEM and FTIR showed that PU/CNTs were coated completely by PANI. Compared with PU/PANI composites, lightweight PU/CNTs/PANI composites exhibited a higher dye-removal ratio of 95.00% at an initial concentration of 10mg/L methyl blue(MB).HGS/CNTs composites with rough structure were prepared by layer-by-layer selfassembly. Then the lightweight HGS/CNTs/PANI composite adsorbents were synthesized by PANI in-situ polymerization.By controlling over the composition of CNTs and the initial concentration of aniline in polymerization, the microstructure was tailored. The relationship between the structures and properties of HGS/CNTs/PANI composites were explored. SEM results showed the structure of the composite adsorbents was rough and porous. The optimization of structure was achieved when HGS/CNTs were used as substrates and the initial concentration of aniline was 0.4mol/L. TG analyses indicated that the weight contents of CNTs and PANI were estimated to be 1.05% and 40.04%, respectively.Adsorption behavior of lightweight HGS/CNTs/PANI composites showed MB initial concentration was 10 mg/L, the maximum of dye-removal ratio could reach 99.98%. XPS, FTIR results showed showed the ion exchange between MB and chlorine ions of PANI after adsorption of MB,The Langmuir isotherm model fitted MB adsorption isotherm and the adsorption kinetics of MB on lightweight HGS/CNTs/PANI composite could be fitted by pseudosecond-order model.