Liu Yucun, Tan Yuanyuan, Liu Zhixue, Che Guangbo
Key Laboratory of Preparation and Application of Environmental Friendly Materials (Jilin Normal University), Ministry of Education, Changchun, 130103, China.
College of Chemistry, Jilin Normal University, Siping, 136000, China.
Soft Matter. 2021 Aug 5;17(30):7227-7235. doi: 10.1039/d1sm00799h.
A C3-symmetric acylhydrazone-based low molecular weight gelator (BHTP) bearing three pyridine units was synthesized and it was found to form a stable supramolecular gel in the mixture solvent of DMSO-H2O. The morphology of the gel as observed by FE-SEM showed a dense sheet structure. Hydrogen bonding and π-π stacking between the gelators were determined as the non-covalent interactions for the gelation, which were investigated thoroughly using XRD, UV-Vis, 1H NMR and FT-IR instruments. BHTP could form pH tolerant supramolecular gels in the widest range of pH values from 1 to 11. The DMSO-H2O (v : v = 1 : 1) gel exhibited selective response to OH- over a series of other anions through the color change from a white gel to a yellow solution, and the OH- response mechanism was proved by 1H NMR experiments. In solution, the lowest detection limit of BHTP for OH- was calculated to be as low as 1.62 × 10-7 M via UV-Vis titration experiments. Finally, encapsulation and controlled release of small molecules such as rhodamine B, crystal violet and methyl orange have been successfully carried out, demonstrating the potential for drug delivery application of this C3-symmetric supramolecular gel. This work opens a novel avenue for the preparation of supramolecular gel-based multiple functional smart materials.
合成了一种带有三个吡啶单元的基于酰腙的C3对称低分子量凝胶因子（BHTP），发现它在DMSO-H2O混合溶剂中形成稳定的超分子凝胶。通过场发射扫描电子显微镜（FE-SEM）观察到的凝胶形态显示为致密的片状结构。确定了凝胶因子之间的氢键和π-π堆积为凝胶化的非共价相互作用，并使用X射线衍射（XRD）、紫外可见光谱（UV-Vis）、核磁共振氢谱（1H NMR）和傅里叶变换红外光谱（FT-IR）仪器对其进行了深入研究。BHTP能够在1至11的最宽pH值范围内形成耐pH值的超分子凝胶。DMSO-H2O（体积比v : v = 1 : 1）凝胶通过从白色凝胶变为黄色溶液的颜色变化，对一系列其他阴离子表现出对OH-的选择性响应，并且通过1H NMR实验证明了OH-响应机制。在溶液中，通过紫外可见光谱滴定实验计算得出BHTP对OH-的最低检测限低至1.62×10-7 M。最后，成功实现了对罗丹明B、结晶紫和甲基橙等小分子的包封和控释，证明了这种C3对称超分子凝胶在药物递送应用方面的潜力。这项工作为制备基于超分子凝胶的多功能智能材料开辟了一条新途径。
