Rymaruk Matthew J, O'Brien Cate T, György Csilla, Darmau Bastien, Jennings James, Mykhaylyk Oleksandr O, Armes Steven P
Dainton Building, Department of Chemistry, The University of Sheffield, Sheffield, S3 7HF, UK.
Present address: Syngenta, Jealott's Hill, Bracknell, Berkshire, RG42 6EY, UK.
Angew Chem Int Ed Engl. 2021 Jun 1;60(23):12955-12963. doi: 10.1002/anie.202101851. Epub 2021 May 1.
We report that polymerization-induced self-assembly (PISA) can be used to prepare lyotropic phases comprising diblock copolymer nano-objects in non-polar media. RAFT dispersion polymerization of benzyl methacrylate (BzMA) at 90 °C using a trithiocarbonate-capped hydrogenated polybutadiene (PhBD) steric stabilizer block in n-dodecane produces either spheres or worms that exhibit long-range order at 40 % w/w solids. NMR studies enable calculation of instantaneous copolymer compositions for each phase during the BzMA polymerization. As the PBzMA chains grow longer when targeting PhBD -PBzMA , time-resolved small-angle X-ray scattering reveals intermediate body-centered cubic (BCC) and hexagonally close-packed (HCP) sphere phases prior to formation of a final hexagonal cylinder phase (HEX). The HEX phase is lost on serial dilution and the aligned cylinders eventually form disordered flexible worms. The HEX phase undergoes an order-disorder transition on heating to 150 °C and a pure HCP phase forms on cooling to 20 °C.
我们报道，聚合诱导自组装（PISA）可用于在非极性介质中制备包含二嵌段共聚物纳米物体的溶致相。在90°C下，使用三硫代碳酸酯封端的氢化聚丁二烯（PhBD）空间稳定剂嵌段，在正十二烷中进行甲基丙烯酸苄酯（BzMA）的RAFT分散聚合，可产生球体或蠕虫状物体，在40% w/w固体含量下呈现长程有序。核磁共振研究能够计算BzMA聚合过程中各相的瞬时共聚物组成。当以PhBD -PBzMA为目标时，随着PBzMA链变长，时间分辨小角X射线散射显示，在最终的六方柱相（HEX）形成之前，会出现中间的体心立方（BCC）和六方密堆积（HCP）球体相。HEX相在连续稀释时消失，排列的圆柱体最终形成无序的柔性蠕虫状物体。HEX相在加热到150°C时会发生有序-无序转变，冷却到20°C时会形成纯HCP相。
