Synthesis of Poly(O-Anisidine)-Coated Kapok Fibers for Removal of Methylene Blue Dye

In this study, an adsorbent for the removal of methylene blue (MB) dye based on kapok fiber coated with Poly (o-Anisidine) (KF-PoA) was synthesized. Raw KF were first pre-treated with NaClO2 to improve wettability. KF was then coated with PoA via in-situ oxidative polymerization with varying amounts of o-Anisidine monomer using a fixed amount of (NH4)2S2O8 as initiator and oxidant. The morphology of the synthesized KF-PoA was observed under a scanning electron microscope. The fabricated adsorbents were subjected to adsorption experiments to assess their performance in removing MB dye. It was found that 2.0 mL of o-Anisidine performed best during the initial batch adsorption test, owing to more adsorption sites. Kinetic studies show rapid removal of MB within 10 min of adsorption. The adsorption process was found to be accurately described by the pseudo-second-order kinetic model with k2=0.0443 min-1 and a calculated equilibrium adsorption capacity at 53.48 mg/g. The removal of MB from the solution may be attributed to the electrostatic interaction between the quaternary ammonium cation head of MB onto the amine groups of PoA.