Jiang Yuchen, Li Guihua, Yang Chenyu, Kong Fangong, Yuan Zaiwu
Key Laboratory of Fine Chemicals in Universities of Shandong, School of Chemistry and Chemical Engineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250353, China.
State Key Laboratory of Biobased Material and Green Papermaking, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250353, China.
Polymers (Basel). 2021 Apr 9;13(8):1219. doi: 10.3390/polym13081219.
Multiresponsive hydrogels have attracted tremendous interest due to their promising applications in tissue engineering, wearable devices, and flexible electronics. In this work, we report a multiresponsive upper critical solution temperature (UCST) composite hydrogel based on poly (acrylic acid-co-acrylamide), PAAc-co-PAAm, sequentially cross-linked by acid-hydrolysis cellulose nanocrystals (CNCs). Scanning electron microscopy (SEM) observations demonstrated that the hydrogels are formed by densely cross-linked porous structures. The PAAc/PAAm/CNC hybrid hydrogels exhibit swelling and shrinking properties that can be induced by multiple stimuli, including temperature, pH, and salt concentration. The driving force of the volume transition is the formation and dissociation of hydrogen bonds in the hydrogels. A certain content of CNCs can greatly enhance the shrinkage capability and mechanical strength of the hybrid hydrogels, but an excess addition may impair the contractility of the hydrogel. Furthermore, the hydrogels can be used as a matrix to adsorb dyes, such as methylene blue (MB), for water purification. MB may be partly discharged from hydrogels by saline solutions, especially by those with high ionic strength. Notably, through temperature-controlled hydrogel swelling and shrinking, doxorubicin hydrochloride (DOX-HCl) can be controllably adsorbed and released from the prepared hydrogels.
多重响应水凝胶因其在组织工程、可穿戴设备和柔性电子等领域的应用前景而备受关注。在这项工作中，我们报道了一种基于聚（丙烯酸-co-丙烯酰胺）（PAAc-co-PAAm）的多重响应上临界溶液温度（UCST）复合水凝胶，该水凝胶通过酸水解纤维素纳米晶体（CNCs）依次交联而成。扫描电子显微镜（SEM）观察表明，水凝胶由密集交联的多孔结构形成。PAAc/PAAm/CNC杂化水凝胶表现出可由多种刺激诱导的溶胀和收缩特性，这些刺激包括温度、pH值和盐浓度。体积转变的驱动力是水凝胶中氢键的形成和解离。一定含量的CNCs可以大大增强杂化水凝胶的收缩能力和机械强度，但过量添加可能会损害水凝胶的收缩性。此外，该水凝胶可用作吸附染料（如亚甲基蓝（MB））的基质以进行水净化。MB可能会被盐溶液部分从水凝胶中释放出来，尤其是那些具有高离子强度的盐溶液。值得注意的是，通过温度控制水凝胶的溶胀和收缩，盐酸阿霉素（DOX-HCl）可以从制备的水凝胶中被可控地吸附和释放。
