(731j) Novel Amphoteric Cryogels for Sr2+ and Cs2+ Ions Removal from Aqueous Solutions

Cryogels are hydrogels that are synthesized at sub-zero temperatures and have super-macroporous structure with interconnected pores, thus offering a unique combination of high interconnected porosity with high mechanical strength. They can be a suitable choice for efficient water or biological media filtration for the removal of heavy metals, microbes and other toxins. In this work, amphoteric cryogels based on N,N-dimethyl acrylamide, methacrylic acid and allylamine, crosslinked by N,N-methylenebisacrylamide were synthesized by free-radical polymerization in cryo-conditions. The cryogels were characterized and used for the removal of cesium and strontium ions from aqueous solutions under different pH values. The results showed lower pH favors the removal of metals but the effect is gradually diminished and after six hours the removals are practically the same. The equilibrium is achieved after 24h of contact and the maximum cryogel loading obtained was 110 mg/g for Cs⁺ and 125 mg/g for Sr²⁺.