Synthesis of hybrid hydrogel of poly(AM co DADMAC)/silica sol and removal of methyl orange from aqueous solutions

A hybrid hydrogel (poly(AM co DADMAC)/silica sol) from acrylamide (AM), diallyl dimethyl ammonium chloride (DADMAC) and silica sot was prepared by aqueous solution polymerization, using N,N'-methylenebisacrylamide (MBA) as crosslinker and ammonium persulfate (APS) as initiator. Its structure and characterization were determined by means of FTIR, SEM, TEM and TG; meanwhile, the effects of silica sot content, pH values and temperatures were studied on the adsorption of methyl orange onto (poly(AM co DADMAC)/silica sot (PAMDS). The adsorption rate data and adsorption equilibrium data were analyzed based on the pseudo-second-order model and four isotherm models respectively. Results obtained from this study indicated that the kinetic behavior accorded with the pseudo-second-order kinetic model. The isotherm behavior can be explained by the Langmuir. Freundluich and Generalized isotherm models. The activation energy was also evaluated for the removal of methyl orange onto PAMDS. This hybrid hydrogel may be used as good adsorbent for the adsorption of anionic dyes from effluents. (C) 2012 Elsevier B.V. All rights reserved.