Antibacterial superabsorbing hydrogels with high saline-swelling properties without gel blockage: Toward ideal superabsorbents for hygienic applications

Abstract

Superabsorbent polymer hydrogels with antibacterial activity were prepared by an ion exchange reaction as a feasible approach to induce high saline absorption without gel blockage. Hydroethanolic solutions of cetyltrimethylammonium bromide were used to modify surface particles of cross-linked sodium acrylate-co-acrylic acid copolymers which already synthesized under defined conditions. Fourier transform infrared spectroscopy was employed to study the structural characteristic of the finished products. The influence of cetyltrimethylammonium bromide on free (in water) and loaded (in saline) swelling capacity as well as antibacterial activity of superabsorbent polymer hydrogels against Staphylococcus aureus was investigated. Modified samples displayed an improved free and loaded swelling in water and saline, as well as no gel-blocking. These improvements were found to be affected by the reaction time, cetyltrimethylammonium bromide concentration, and water percentage in the solvent mixture. The results from energy dispersive X-ray analysis showed that cetyltrimethylammonium bromide was distributed uniformly in the superabsorbent polymer hydrogel particle surface. Moreover, the modified superabsorbent polymer hydrogels showed high antibacterial activity against S. aureus. Both bacteriostatic and bactericide effects were observed depending on the reaction conditions. Overall, several improvements were concurrently achieved via a single cost-effective post-treatment on the superabsorbent polymer hydrogel particles. Therefore, the results can effectively be used in designing larger scale production of antibacterial superabsorbent polymer hydrogels with desirable swelling properties in hygiene applications.