Double-crosslinked reversible redox-responsive hydrogels based on disulfide-thiol interchange
Double-crosslinked reversible redox-responsive hydrogels based on disulfide-thiol interchange
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DOI：
10.1002/pola.29539
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发表时间：
2019-11-14
影响因子：
--
通讯作者：
Voit, Brigitte
中科院分区：
文献类型：
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作者：
Che, Yunjiao;Zschoche, Stefan;Voit, Brigitte
我们提出了基于聚（N-异丙基丙烯酰胺）或聚（丙烯酰胺）的新型氧化还原响应性水凝胶，其由可逆二硫键交联剂N，N '-双（丙烯酰基）胱胺和永久交联剂N，N '-亚甲基双丙烯酰胺组成，用于微流体应用。溶胀/去溶胀行为的机理始于二硫键的断裂和重新形成，导致交联密度和交联点的变化。拉曼和紫外-可见光谱证实硫醇-二硫键交换转化效率高达99%。流变学分析表明，水凝胶的E模量取决于交联密度，并且可以在至少5个循环内在高刚度和低刚度状态之间重复操纵而没有显著降低。动力学研究表明，随着氧化还原反应的进行，凝胶的机械强度发生变化。该过程比水凝胶中的自主扩散快得多。此外，合作扩散系数（D-coop）表明，水凝胶的溶胀过程中的还原反应的影响。最后，这种可逆切换的氧化还原行为的庞大的水凝胶可以证明在微结构的水凝胶点，通过短期的微图案化过程。玻璃基底上的这些水凝胶点还显示出对从缩小尺寸的水凝胶形状已知的循环溶胀和收缩过程的期望的短响应时间。这种具有氧化还原敏感性交联剂的刺激响应性水凝胶为微流体应用中的传感和分离交换分析物开辟了新的途径。(c)2019 Wiley Periodicals，Inc. J. Polym.科学，部分A：聚合物。2019年化学
We present novel redox-responsive hydrogels based on poly(N-isopropylacrylamide) or poly(acrylamide), consisting of a reversible disulfide crosslinking agent N,N '-bis(acryloyl)cystamine and a permanent crosslinking agent N,N '-methylenebisacrylamide for microfluidic applications. The mechanism of swelling/deswelling behavior starts with the cleavage and reformation of disulfide bonds, leading to a change of crosslinking density and crosslinking points. Raman and ultraviolet-visible spectroscopy confirm that conversion efficiency of thiol-disulfide interchange up to 99%. Rheological analysis reveals that the E modulus of hydrogel is dependent on the crosslinking density and can be repeatedly manipulated between high- and low-stiffness states over at least 5 cycles without significant decrease. Kinetic studies showed that the mechanical strength of the gels changes as the redox reaction proceeds. This process is much faster than the autonomous diffusion in the hydrogel. Moreover, cooperative diffusion coefficient (D-coop) indicates that the swelling process of the hydrogel is affected by the reduction reaction. Finally, this reversibly switchable redox behavior of bulky hydrogel could be proven in microstructured hydrogel dots through short-term photopatterning process. These hydrogel dots on glass substrates also showed the desired short response time on cyclic swelling and shrinking processes known from downsized hydrogel shapes. Such stimuli-responsive hydrogels with redox-sensitive crosslinkers open a new pathway in exchanging analytes for sensing and separating in microfluidics applications. (c) 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019