화학공학소재연구정보센터
Separation Science and Technology, Vol.53, No.14, 2170-2185, 2018
Pectin graft copolymer-montmorillonite composite: Synthesis, swelling and divalent metal ion adsorption
A novel graft copolymer gel made up of pectin (Pec), 2-(methacryloyloxyethyl)trimethylammonium chloride (METAC), 2-acrylamido-2-methyl-1-propane sulfonic acid (AMPS) and its composite with montmorillonite (MMT) were prepared using methylenebisacrylamide (MBA) as cross-linker via microwave irradiation and characterized using Fourier transform infrared (FTIR), Thermogravimetric Analysis (TGA) and Scanning electron microscopy (SEM) techniques. Swelling studies were carried out under different pH conditions. The graft copolymer gel and its composite showed maximum swelling in neural medium (pH 7.1) and the swelling process followed second order kinetics. The mechanism of water transport is found to be a Less Fickian diffusion process. The adsorption capacities of the graft copolymer gel and the composite towards divalent metal ions (Cu2+, Pb2+ and Hg2+) were evaluated. The adsorption capacity of the representative samples, Pec-g-poly(METAC-co-AMPS)-A5 and Pec-g-poly(METAC-co-AMPS)/MMT-C2 respectively for Cu2+ are 30.71 and 39.18mg/g; for Pb2+ are 58.06 and 79.78mg/g and for Hg2+ are 12.16 and 19.58mg/g. The re-usability of the materials was also evaluated. The % recovery for the above two systems towards metals ion are 87.91 and 63.46 for Cu2+, 32.13 and 58.30 for Pb2+ and 78.53 and 51.92 for Hg2+. respectively. The adsorption isotherm studies indicated the adsorption of Pb2+, Cu2+ and Hg2+ in both samples is explained best by the Freundlich model except of Hg2+ by Pec-g-poly(METAC-co-AMPS)-A5, which is best explained by the Langmuir model.