Enhancing swelling kinetics of pNIPAM lyogels: The role of crosslinking, copolymerization, and solvent

作者：Kathrin Marina Eckert, Jelisa Bonsen, Anja Hajnal, Johannes Gmeiner, Jonah Hasse, Muhammad Adrian, Julian Karsten, Patrick A. Kißling, Alexander Penn, Bodo Fiedler, Gerrit Albert Luinstra, Irina V. Smirnova · 发表于：Fluid Phase Equilibria · 年份：2025 · DOI：10.1016/j.fluid.2025.114462 · 被引用次数：13 · 研究领域：Hydrogels: synthesis, properties, applications、Aerogels and thermal insulation、Advanced Cellulose Research Studies

Stimuli-responsive lyogels are known for their ability to undergo significant macroscopic changes when exposed to external stimuli. While thermo-responsive gels, such as poly-N-isopropylacrylamide (pNIPAM), have been extensively studied across various applications, solvent-induced swelling has predominantly been investigated in aqueous solutions. This study explores the tailoring of lyogel formulations for future applications by controlling their solvent-induced swelling behavior, comparing both homopolymeric and semi-interpenetrating polymer networks (semi-IPNs). It is structured in two parts: the first focuses on characterization techniques, including NMR relaxometry, swelling degree measurements, mechanical testing, and SEM analysis, while the second part delves into swelling kinetic analysis, applying solvent exchange as a stimulus for varying gel formulations and solvents. In contrast to most previous studies, the impact of chemical and physical crosslinking, as well as copolymer inclusion, on the swelling behavior and mechanical properties of lyogels in organic solvents is examined and compared with solvent-induced swelling kinetics measurements. The results demonstrate that increasing chemically crosslinking in homopolymers and physically crosslinking in semi-IPNs enhances mechanical stability, while improving mass transport properties and solvent exchange kinetics. However, increases degree of crosslinking results in a prolonged response time to the solvent exchange s...