Abstract:

Crystallization mechanism and morphology control is a critical concern for the crystal engineering study and relevant application. For example, urate crystallization is important for the study of gout induced by hyperuricemia. Herein, using PP membrane as a base membrane, 8 kinds of hydrogel composite membranes (HCMs) with different polymer composition were prepared by ultraviolet cross-linking method, and PEGDA-NIPAM hydrogel materials with excellent interface induced crystallization performance were selected for continuous optimization. Based on the comprehensive analysis of the reproducibility of the hydrogel preparation process and the results of NaCl droplet evaporation experiments, PEGDA-NIPAM (molar ratio is 2∶1) material was used to prepare hydrogel slices (HGS). This type of HGS had a uniform surface, vertical structure and thickness, and the slice quality can be quantified by the surface area. Studies on the NaCl salt dissolution adsorption-crystallization experiment illustrated that the prepared HGS possesses hybrid pH-temperature responsibility for high-efficiency interfacial nucleation and concentration regulation functions, which can be used as a functional micro-platform to control solution crystallization. HGS was introduced into the mixed crystal slurry of uric acid dihydrate crystals (UAD) and simulated body fluids (SBF) to adjust the crystallization process and crystal morphology of sodium urate monohydrate crystals (MSUM). Studies showed that the addition of HGS can strengthen the crystal conversion process, and the crystallization duration was shortened from 72h to 20h. At the same time, HGS can also promote crystal growth and crystal agglomeration. Diverse crystal morphologies can be obtained in an efficient manner, which entirely distinguished from the one prepared via no-HGS. This work explored a new path for further revealing and developing crystal morphology control with hydrogel interfacial materials.

Key words: urate crystals, morphology selectivity, hydrogel, nucleation, crystal habit, crystallization regulation

摘要：

结晶机理和晶习调控是结晶工程研究和应用的关键。例如，尿酸盐结晶对高尿酸血症引起的痛风的研究有重要意义。使用制造的仿生水凝胶材料控制结晶是一种新颖的方法，本文以聚丙烯（PP）膜作为基膜，使用紫外光交联法制备了8种不同聚合结构的水凝胶复合膜，优选了界面诱导结晶性能优异的聚乙二醇二甲基丙烯酸酯-N-异丙基丙烯酰胺（PEGDA-NIPAM）水凝胶材料继续优化。综合分析NaCl液滴蒸发实验和水凝胶制备的可重复性，选用PEGDA-NIPAM（物质的量比2∶1）制备水凝胶切片（HGS）。该种HGS具有均匀表面、垂直结构，厚度、切片质量可通过面积进行直接量化制备。研究NaCl盐溶解吸附-结晶实验，表明制备的HGS拥有pH-温度混合的高效界面成核和浓度调控功能，可作为调控溶液结晶的功能微平台。将HGS引入二水合尿酸晶体与模拟体液的混合晶浆中，调控尿酸钠一水合物晶体（MSUM）的结晶过程和晶体形貌。结果表明，HGS的加入可以强化晶体转化过程，结晶时间由传统方法的72h缩短为水凝胶片层法的20h。同时，HGS还能促进晶体生长和晶体间团聚，能快速获得不同层级多尺度结构的晶体，形成与无HGS条件制备的晶体完全不同的全新晶习。本工作为揭示发展相关晶体的形貌控制方法提供了新的思路。

关键词: 尿酸盐晶体, 形态选择性, 水凝胶, 成核, 晶习, 结晶调控