Li Xue, Cai Xiangbin, Gao Yongfeng, Serpe Michael J
Department of Chemistry, University of Alberta, Edmonton, AB T6G 2G2, Canada.
J Mater Chem B. 2017 Apr 21;5(15):2804-2812. doi: 10.1039/c7tb00426e. Epub 2017 Mar 30.
Temperature and pH responsive semi-interpenetrating network (semi-IPN) hydrogel-based bilayer actuators were fabricated by generating a poly(N-isopropylacrylamide) (pNIPAm)-based hydrogel in the presence of positively charged polyelectrolyte poly(diallyldimethylammonium chloride) (pDADMAC) on a layer of gold-coated polydimethylsiloxane (PDMS). The bilayers showed unique bidirectional bending behavior in response to solution temperature and pH, which is a result of the modulation of the hydrogel solvation state in response to solution temperature and pH changes. The behavior described here is vastly different than what is observed from bilayers composed of just pNIPAm. The direction and degree of bending of the device could be easily adjusted by tuning the composition of the hydrogel layer. We also showed that the bilayers could be used as stimulus-induced grippers and for controlled/triggered small molecule delivery, which can make the bilayers useful for various biomedical applications.
通过在涂有金的聚二甲基硅氧烷（PDMS）层上，在带正电荷的聚电解质聚二烯丙基二甲基氯化铵（pDADMAC）存在的情况下生成基于聚（N-异丙基丙烯酰胺）（pNIPAm）的水凝胶，制备了温度和pH响应型半互穿网络（semi-IPN）水凝胶基双层致动器。这些双层在溶液温度和pH响应下表现出独特的双向弯曲行为，这是水凝胶溶剂化状态响应溶液温度和pH变化而调制的结果。这里描述的行为与仅由pNIPAm组成的双层所观察到的行为有很大不同。通过调整水凝胶层的组成，可以轻松调节器件的弯曲方向和程度。我们还表明，这些双层可以用作刺激诱导的夹具和用于受控/触发的小分子递送，这可以使双层可用于各种生物医学应用。
