Designing Stable Macroporous Hydrogels: Effects of Single and Dual Surfactant Systems on Porous Architecture, Absorption Capacity, and Mechanical Strength

Abstract

This study explores dual surfactant systems to enhance the pore structure, swelling behavior, and mechanical properties of porous 2-acrylamido-2-methylpropanesulfonic acid (AMPS) hydrogels for potential biomedical applications, such as wound dressings. Hydrogels were synthesized using combinations of nonionic surfactants (Pluronic F127 (P) and Tween 20 (T)) and an anionic surfactant (sodium dodecyl sulfate, SDS). By adjusting of the surfactant ratios, the study aimed to achieve optimal porosity and mechanical stability under both dry and wet conditions. The morphological analysis revealed that the dual surfactant systems, particularly 50%P:50%T and 80%P:20%SDS, produced more uniform and interconnected porous structures, with average pore sizes of 25.61 ± 8.99 and 29.72 ± 8.53 μm, respectively. Swelling tests showed that the 50%P:50%T sample had the highest swelling capacity, absorbing up to 5730%, while maintaining its structural integrity. Rheological analysis confirmed that the dual surfactant hydrogels exhibited higher storage modulus (G′), with 50%P:50%T showing values of 4758 Pa (dry) and 1541 Pa (wet), demonstrating enhanced mechanical stability. Additionally, the tan delta values remained below 0.1 over a greater strain range. These findings suggest that dual surfactant systems can considerably improve the porous architecture, absorption capacity, and mechanical strength of the hydrogels, making them more suitable for demanding biomedical applications.