In situ polymerized poly(acrylic acid)/alumina nanocomposites for Pb2+ adsorption

In this study, two poly(acrylic acid)/alumina (PAA/alumina) nanocomposites with varied polymer loadings were prepared via in situ polymerization of preadsorbed acrylic acid. One composite would have a ~1/4-monolayer polymer coverage, while the other had a ~2-monolayer coverage. The produced composite materials were characterized in the adsorptive behavior of Pb 2+ from aqueous solution. When there was less PAA produced in a nanocomposite sample, there was higher Pb 2+ sorption capacity due to potentially less blocked alumina pores by in situ formed PAA. Isothermal and kinetic models for Pb 2+ sorption were applied by considering the effects of the initial Pb 2+ concentration and the contact time. The adsorption kinetics was best expressed using the pseudo-second-order equation. Through the isothermal studies, the maximum Pb 2+ monolayer adsorption capacity of 167.79 mg/g was recorded for the composite with higher PAA loading.