Integrated synthesis and characterization of some porous polyacrylamide-based composites for cationic sorption from aqueous liquid wastes

摘要

Three types of polymeric-inorganic composite cation-exchangers were synthesized by impregnation of inorganic precipitates of tin(Ⅳ) silicate and tin(Ⅳ) antimonate with different ratios into polyacrylamide matrices to form polyacrylamide stannic silicate (PAmSnSi), poly-acrylamide stannic antimonate (PAmSnSb), and polyacrylamide stannic silicoantimonate (PAmSnSiSb) hybrid composites. These materials were characterized by X-ray powder diffraction, FTIR, SEM, BET surface area, DTA, and TGA. They possessed high surface areas with mesoporous texture; PAmSnSi, PAmSnSb, and PAmSnSiSb exhibited type Ⅳ-H4, Ⅳ-H3, and Ⅳ-H2 N_2-adsorption, respectively. They showed improved chemical stabilities which was in the order of PAmSnSb ＞ PAmSnSi ＞ PAmSnSiSb in HNO_3, while their stability order in HCl was PAmSnSi ＞ PAmSnSb ＞ PAmSnSiSb. The effect of experimental parameters such as temperature, concentration, and pH on the properties of material has been studied. Distribution behaviors for radioactive aqueous ~(134)Cs~+, ~(60)Co~(2+), and ~(90)Sr~(2+) as well as Cd~(2+) ions on the three composite ion exchangers were investigated to understand the cation-exchange performance of the materials; some binary separations were predicted and compared.