荷兰埃因霍温理工大学Albert P. H. J. Schenning团队报道了氧化还原响应型液晶沉淀聚合的花状胶体粒子制备方法。相关研究成果于2021年10月21日发表在国际顶尖学术期刊《德国应用化学》。

尽管存在大量各向异性无机粒子，但制备非球形聚合物粒子仍然具有挑战性，尤其是具有角度特征的聚合物粒子。

该文中，研究人员报告了通过沉淀聚合由苯甲酸官能化丙烯酸酯和二硫化物官能化二丙烯酸酯组成的液晶单体混合物来合成单分散、花状液晶（LC）聚合物粒子。少量二硫键功能化二丙烯酸酯的引入(≤ 10%（wt%）诱导形成花状。通过提高聚合温度，粒子的形状可以从花状到圆盘状再到球形。溶剂环境对颗粒大小也有显著影响。时间分辨TEM表明，最终的粒子形态是在聚合的早期阶段形成的，随后的聚合导致粒子继续生长，而不影响形态。最后，花状颗粒在还原条件下的降解速度比球形颗粒快得多，这是因为它们具有更高的表面体积比。

该研究工作介绍了一种简便且可扩展的非球形各向异性有机粒子的制备方法，可能会产生从智能涂层到氧化还原响应载体系统的潜在应用。

附：英文原文

Title: Flower-like colloidal particles through precipitation polymerization of redox responsive liquid crystals

Author: Xiaohong Liu, Mohammad-Amin Moradi, Tom Bus, Michael G. Debije, Stefan A. F. Bon, Johan P.A. Heuts, Albert P. H. J. Schenning

Issue&Volume: 2021-10-21

Abstract: Despite the plethora of available anisotropic inorganic particles, it remains challenging to fabricate non-spherical polymer particles, especially with angular features. Here we report on the synthesis of monodisperse, flower-like, liquid crystalline (LC) polymer particles by precipitation polymerization of an LC monomer mixture consisting of benzoic acid-functionalized acrylates and disulfide-functionalized diacrylates. Introduction of a minor amount of disulfide-functionalized diacrylates (≤ 10 wt%) induced the formation of flower-like shapes. The shape of the particles can be tuned from flower- to disk-like to spherical by elevating the polymerization temperature. The solvent environment also has a pronounced effect on the particle size. Time-resolved TEM reveals that the final particle morphology was formed in the early stages of the polymerization and that subsequent polymerization resulted in continued particle growth without affecting the morphology. Finally, the degradation of the particles under reducing conditions was much faster for flower-like particles than for spherical particles, a result of their higher surface-to-volume ratio. This work introduces a facile and scalable preparation of non-spherical anisotropic organic particles which may lead to potential applications ranging from smart coatings to redox responsive carrier systems..

DOI: 10.1002/anie.202111521

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202111521