a study on swelling behavior and sorbent properties of hydrogels based on acrylic acid

In recent years, the development of modern absorbent materials has attracted increasing attention due to their crucial role in a wide range of applications, including agriculture, biomedicine, hygiene products, and environmental protection. polymers of partially neutralized acrylic acid crosslinked with carboxymethylcellulose were used in the work. with an increase in the concentration of the crosslinking agent, a decrease in the swelling of the hydrogel is observed. at low concentrations of the crosslinking agent, the dependence is directly proportional, an increase in concentration above 10% violates this dependence. the study of the exchange equilibrium of ions mg2+, cd2+, ni2+, co2+, cu2+, cr3+, ca2+, and al3+ ions swelling with hydrogel established that, according to their affinity to ion exchangers, the studied metal ions are arranged in the following series: cd2+> cr3+> cu3+> mg2+> co2+> ni2+. this series was derived without taking into account such features as the degree of saponification of aa, the concentration of the initial solutions, but using the maximum sorption values for the given metals. the exchange capacity of cadmium, cobalt, nickel, and chromium ions reaches a maximum at a degree of saponification with acrylic acid of 20%. the introduction of more alkali increases the swelling of the gel or a decrease in the degree of saponification, leading to a decrease in water absorption, reduces the exchange capacity of the polymer with respect to these metals, probably due to the regulation of the pore size of the gel.