Effect of the coupling agent on the properties of poly(acrylic acid)−Al2O3 interpenetrating hybrids and sorption of metal ions

Abstract

AbstractIn this work we present the synthesis and characterization of a hybrid material based on poly(acrylic acid) (PAA), 3‐(trimethoxysilyl)propylmethacrylate (TMPM) and aluminium oxide (Al2O3). Hybrid materials applied for divalent cation retention were lead(II), cadmium(II), nickel(II) and copper(II) and the effect of the coupling agent TMPM was evaluated. The synthesis of the materials was carried out using a simultaneous radical polymerization/sol‐gel process for obtaining Al2O3−PAA composites using different amounts of TMPM as coupling agent. The physical and chemical properties of the hybrids were investigated using infrared spectroscopy, N2 absorption, SEM and TGA. The results indicate that all of the materials were simultaneous interpenetrating networks and that the morphologies and the properties depend on the amount of TMPM used. The metal ion retention properties were studied by a batch equilibrium procedure and sorption experiments were carried out under non‐competitive ion conditions. The hybrid exhibited metal ion uptake and dependence of metal sorption on the coupling agent content. Moreover, equilibrium sorption results are well described by Langmuir isotherms, and the sorption for different cations showed the following trend: Ni(II) < Cu(II) < Cd(II) < Pb(II). © 2014 Society of Chemical Industry