| 초록 |
Stimuli-responsive hydrogels have been fascinating researchers because they showed changes of their volume or mechanical properties by external stimuli (i.e. temperature, pH, metal ions and so on). Allyl-substituted alginate (Alg) underwent gelation with N-isopropylacrylamide (NIPAM) monomers via UV-mediated radical reactions. The swelling behavior of the hydrogels was different depending on the NIPAM amounts, pH, temperature, and the presence of metal ions. The mechanical strength of Alg-NIPAM hydrogels increased as increasing the NIPAM amount, increasing temperature, and adding metal ions which were captured by alginates. It appeared that capturing metal ions made additional crosslinking inside Alg-NIPAM hydrogels, resulting in the double-network. Alg-NIPAM hydrogels showed shape-memory properties with metal-ion addition and also went through the reversible size-change under a temperature cycle, which indicated the possibilities of using them as shape memory materials. |
