Liu Jie, Lou Xianwen, Schotman Maaike J G, Marín San Román Patricia P, Sijbesma Rint P
Institute for Complex Molecular Systems, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands.
Institute for Complex Molecular Systems, Department of Biomedical Engineering, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands.
Gels. 2022 Sep 27;8(10):615. doi: 10.3390/gels8100615.
The design of photo-responsive supramolecular hydrogels based on coumarin dimerization and de-dimerization is described. The photo-responsive coumarin unit is chemically incorporated into an oligo(ethylene glycol) (OEG) bis-urea amphiphile that is capable of co-assembling with non-functionalized OEG amphiphile, to form supramolecular fibers. UV light with two different wavelengths (365 nm and 254 nm) is employed to induce a photo-reversible dimerization and de-dimerization process of coumarin units, respectively. The co-assembled solutions could be photo-crosslinked to induce a sol-to-gel transition through dimerization of coumarin with 365 nm UV light, and de-dimerization occurs with 254 nm UV light, to provide a weaker gel. In this system, the mechanical strength of supramolecular hydrogels can be tuned using the irradiation time, providing precise control of gelation in a supramolecular hydrogelator.
本文描述了基于香豆素二聚化和去二聚化的光响应超分子水凝胶的设计。光响应香豆素单元通过化学方法引入到聚乙二醇（OEG）双脲两亲分子中，该两亲分子能够与非功能化的OEG两亲分子共组装形成超分子纤维。分别使用两种不同波长（365 nm和254 nm）的紫外光来诱导香豆素单元的光可逆二聚化和去二聚化过程。共组装溶液可以通过365 nm紫外光使香豆素二聚化而发生光交联，从而诱导溶胶-凝胶转变，而用254 nm紫外光时则发生去二聚化，形成较弱的凝胶。在该体系中，超分子水凝胶的机械强度可以通过照射时间进行调节，从而在超分子水凝胶形成剂中实现对凝胶化的精确控制。
