Preparation and characterization of hexagonal mesoporous silica/polyacrylamide nanocomposite capsule (PAM-HMS) for dye removal from aqueous solutioxns

In the present study, hexagonal mesoporous silica-polyacrylamide (PAM-HMS) nano-composite was synthesized by inverse pickering emulsion polymerization method and was applied for the removal of direct yellow 86 (DY86). XRD, BET, SEM and FfIR analysis were applied to identify the structure and morphology of synthesized nano-composite. The effects of some basic parameters such as pH of solution, adsorbent dosage, initial dye concentration, contact time and temperature on the removal efficiency were investigated. After polymerization reaction, BET surface area of HMS was reduced from 882 m(2)/g to 10.61 m(2)/g which confirms the formation of polymer and the presence of polyacrylamide. The results of equilibrium study showed that adsorption of DY86 on nanocomposite followed the Langmuir isotherm accompanying with high maximum adsorption capacity of 1000 mg/g and mono-layer adsorption. Kinetic and thermodynamic studies also proved that Pseudo-second order kinetic model is the predominant model and the adsorption process is endothermic. (C) 2017 Elsevier B.V. All rights reserved.