Department of Earth and Planetary Sciences and Origins of Life Initiative, Harvard University, 100 Edwin H. Land Bvld., Cambridge, MA 02138, USA.
Department of Chemical Engineering, Biotechnology and Materials. FCFM, Universidad de Chile, Beauchef 851, Santiago 8370456, Chile.
Biomolecules. 2019 Aug 8;9(8):352. doi: 10.3390/biom9080352.
Giant vesicles with several-micrometer diameters were prepared by the self-assembly of an amphiphilic block copolymer in the presence of the Belousov-Zhabotinsky (BZ) reaction. The vesicle is composed of a non-uniform triblock copolymer synthesized by multi-step reactions in the presence of air at room temperature. The triblock copolymer contains poly(glycerol monomethacrylate) (PGMA) as the hydrophilic block copolymerized with tris(2,2'-bipyridyl)ruthenium(II) (Ru(bpy)), which catalyzes the BZ reaction, and 2-hydroxypropyl methacrylate (HPMA) as the hydrophobic block. In this new approach, the radicals generated in the BZ reaction can activate a reversible addition-fragmentation chain transfer (RAFT) polymerization to self-assemble the polymer into vesicles with diameters of approximately 3 µm. X-ray photoelectron spectroscopy (XPS) measurements demonstrated that the PGMA--Ru(bpy)--PHPMA triblock copolymer is brominated and increases the osmotic pressure inside the vesicle, leading to micrometer-sized features. The effect of solvent on the morphological transitions are also discussed briefly. This BZ strategy, offers a new perspective to prepare giant vesicles as a platform for promising applications in the areas of microencapsulation and catalyst support, due to their significant sizes and large microcavities.
通过两亲嵌段共聚物在 Belousov-Zhabotinsky（BZ）反应存在下的自组装，制备了具有数微米直径的巨大囊泡。囊泡由在室温下空气中存在的多步反应合成的非均相三嵌段共聚物组成。三嵌段共聚物含有聚（甲基丙烯酸甘油酯）（PGMA）作为亲水嵌段与三（2,2'-联吡啶）钌（II）（Ru(bpy)）共聚，Ru(bpy) 催化 BZ 反应，以及 2-羟丙基甲基丙烯酸酯（HPMA）作为疏水嵌段。在这种新方法中，BZ 反应中产生的自由基可以激活可逆加成-断裂链转移（RAFT）聚合，将聚合物自组装成直径约 3 µm 的囊泡。X 射线光电子能谱（XPS）测量表明，PGMA--Ru(bpy)--PHPMA 三嵌段共聚物被溴化，增加了囊泡内的渗透压，导致出现微米级特征。还简要讨论了溶剂对形态转变的影响。由于其显著的尺寸和大微腔，这种 BZ 策略为制备巨大囊泡提供了一个新视角，作为微封装和催化剂载体领域有前途的应用的平台。
