Swelling and Mechanical Properties of a Temperature‐Sensitive Dextran Hydrogel and its Bioseparation Applications

Summary: A series of temperature‐sensitive dextran hydrogels (poly(NIPA‐co‐GMA‐Dex)) were synthesized by the copolymerization of glycidyl methacrylate‐derivatized dextran (GMA‐Dex) and N‐isopropylacrylamide (NIPA) in aqueous solution. Their swelling and mechanical properties and bioseparation behaviors were studied. It is found that poly(NIPA‐co‐GMA‐Dex) hydrogels simultaneously exhibit much better swelling and mechanical properties. The interactions between poly(NIPA‐co‐GMA‐Dex) hydrogels and sodium dodecylsulfate (SDS), Rutin, and DL‐α‐alanine were different because of their different hydrophobic nature, polarity, and molecular structure, and obviously depend on the temperature: the mechanism is discussed. In addition, using poly(NIPA‐co‐GMA‐Dex) hydrogels as the absorbents, gel‐extraction separation experiments of dextran and BSA solutions showed that the separation ability of poly(NIPA‐co‐GMA‐Dex) hydrogels obviously increased upon reaching the LCST. Temperature dependence of the swelling ratio of the PNIPA (▪) and poly(NIPA‐co‐GMA‐Dex) hydrogels (r = 0.2(•), 0.4 (▴), 0.5 (▾), 0.6(♦), 0.8 (+)). magnified image Temperature dependence of the swelling ratio of the PNIPA (▪) and poly(NIPA‐co‐GMA‐Dex) hydrogels (r = 0.2(•), 0.4 (▴), 0.5 (▾), 0.6(♦), 0.8 (+)).