Zhang Zheng, Li Yajuan, Geng Lijun, Feng Guoliang, Ren Jujie, Yu Xudong
College of Science, and Hebei Research Center of Pharmaceutical and Chemical Engineering, Hebei University of Science and Technology, Yuhua Road 70, Shijiazhuang 050080, PR China.
Inorg Chem. 2020 Mar 16;59(6):3974-3982. doi: 10.1021/acs.inorgchem.9b03662. Epub 2020 Feb 28.
Self-healing and tough gels with intriguing white-light emission, prepared by lanthanide metal ions, are highly desirable and remain a challenging topic. In this study, we present the preparation of a hybrid gel that contains poly(methyl methacrylate)/polyacrylic acid (PMMA/PAA) as the organic network and titania as the inorganic network, which are interpenetrating and linked by lanthanide metal ions. Interestingly, the gelation process for the organic phase allows for the efficient phase separation of the water-THF mixture (separation efficiency: >88%), either by the heating-cooling process or by the room temperature gelation that originated from xerogels. The as-prepared gels are self-healing and robust, based on the hybrid networks and dynamic coordination interactions. Specifically, the hybrid gels exhibit various colors of luminescence, depending on either the stoichiometric ratio of Eu and Tb or the excitation wavelengths. Upon excitation by the 365 nm light, the hybrid gel with Eu/Tb ions (molar ratio 1:30) demonstrates a white-light emission color. The results also show that the gels prepared by only Eu and Tb possess different morphologies, surface areas, and contact angles. This work presents, for the first time, the crucial role of lanthanide ions for preparing a robust, self-healing hybrid gel with interpenetrating networks in the polymerization process, and the resulting hydrophobic surfaces are related to the phase-selective ability of the gels.
由镧系金属离子制备的具有迷人白光发射的自愈合且坚韧的凝胶是非常理想的，但仍然是一个具有挑战性的课题。在本研究中，我们展示了一种杂化凝胶的制备方法，该凝胶包含聚（甲基丙烯酸甲酯）/聚丙烯酸（PMMA/PAA）作为有机网络和二氧化钛作为无机网络，它们相互贯穿并通过镧系金属离子连接。有趣的是，有机相的凝胶化过程允许水 - 四氢呋喃混合物进行高效相分离（分离效率：>88%），这可以通过加热 - 冷却过程或由干凝胶引发的室温凝胶化来实现。基于杂化网络和动态配位相互作用，所制备的凝胶具有自愈合和坚固的特性。具体而言，杂化凝胶根据铕和铽的化学计量比或激发波长呈现出各种颜色的发光。在365 nm光激发下，具有铕/铽离子（摩尔比1:30）的杂化凝胶呈现出白光发射颜色。结果还表明，仅由铕和铽制备的凝胶具有不同的形态、表面积和接触角。这项工作首次展示了镧系离子在聚合过程中制备具有相互贯穿网络的坚固、自愈合杂化凝胶的关键作用，并且所得的疏水表面与凝胶的相选择能力有关。
