Yao Yalan, Wang Yige, Li Zhiqiang, Li Huanrong
School of Chemical Engineering and Technology, Hebei University of Technology , GuangRong Dao 8, Hongqiao District, Tianjin 300130, People's Republic of China.
Langmuir. 2015 Nov 24;31(46):12736-41. doi: 10.1021/acs.langmuir.5b03102. Epub 2015 Nov 10.
We present herein an easy way to prepare novel responsive hydrogels by simply doping lanthanide complexes into a polymer hydrogel, poly(2-acrylamido-2-methyl-1-propanesulfonicacid) (PAMPSA). The resulting hybrid hydrogels can be readily processed into a range of shapes. Both the on-off luminescence switching and the healable properties are simultaneously achieved in the resulting responsive hybrid hydrogels. They exhibit effectively self-healing performance without any external stimulus and reversible "on-off" luminescence switching triggered by exposure to acid-base vapor. The key to this on-off luminescence switching behavior is that the protonation of the organic ligands compete with full coordination to Ln(3+) and that incomplete coordination affects the luminescence yield. The high proton strength in the resulting hydrogels makes the doped lanthanide complexes unstable, and ammonia (or triethylamine) vapor can dramatically decrease the proton strength through neutralization, driving the full coordination of the ligand to Ln(3+).
我们在此展示了一种制备新型响应性水凝胶的简便方法，即只需将镧系配合物掺杂到聚合物水凝胶聚（2-丙烯酰胺基-2-甲基-1-丙烷磺酸）（PAMPSA）中。所得的杂化水凝胶可以很容易地加工成一系列形状。在所得的响应性杂化水凝胶中同时实现了发光的开-关切换和可愈合性能。它们在没有任何外部刺激的情况下表现出有效的自愈性能，并且通过暴露于酸碱蒸汽触发可逆的“开-关”发光切换。这种发光开-关切换行为的关键在于有机配体的质子化与与Ln(3+)的完全配位相互竞争，并且不完全配位会影响发光产率。所得水凝胶中的高质子强度使掺杂的镧系配合物不稳定，而氨（或三乙胺）蒸汽可以通过中和作用显著降低质子强度，促使配体与Ln(3+)完全配位。
