Hunter Saul J, Armes Steven P
Department of Chemistry, Dainton Building, University of Sheffield, Brook Hill, Sheffield, South Yorkshire S3 7HF, U.K.
Langmuir. 2020 Dec 29;36(51):15463-15484. doi: 10.1021/acs.langmuir.0c02595. Epub 2020 Dec 16.
Block copolymer nanoparticles prepared via polymerization-induced self-assembly (PISA) represent an emerging class of organic Pickering emulsifiers. Such nanoparticles are readily prepared by chain-extending a soluble homopolymer precursor using a carefully selected second monomer that forms an insoluble block in the chosen solvent. As the second block grows, it undergoes phase separation that drives in situ self-assembly to form sterically stabilized nanoparticles. Conducting such PISA syntheses in aqueous solution leads to hydrophilic nanoparticles that enable the formation of oil-in-water emulsions. Alternatively, hydrophobic nanoparticles can be prepared in non-polar media (e.g., -alkanes), which enables water-in-oil emulsions to be produced. In this review, the specific advantages of using PISA to prepare such bespoke Pickering emulsifiers are highlighted, which include fine control over particle size, copolymer morphology, and surface wettability. This has enabled various fundamental scientific questions regarding Pickering emulsions to be addressed. Moreover, block copolymer nanoparticles can be used to prepare Pickering emulsions over various length scales, with mean droplet diameters ranging from millimeters to less than 200 nm.
通过聚合诱导自组装（PISA）制备的嵌段共聚物纳米颗粒是一类新兴的有机皮克林乳化剂。此类纳米颗粒可通过使用精心挑选的第二单体对可溶性均聚物前体进行扩链来轻松制备，该第二单体在所选溶剂中形成不溶性嵌段。随着第二嵌段的增长，它会发生相分离，从而驱动原位自组装形成空间稳定的纳米颗粒。在水溶液中进行此类PISA合成会产生亲水性纳米颗粒，从而能够形成水包油乳液。或者，可以在非极性介质（如正构烷烃）中制备疏水性纳米颗粒，进而能够生产油包水乳液。在这篇综述中，强调了使用PISA制备此类定制皮克林乳化剂的具体优势，其中包括对粒径、共聚物形态和表面润湿性的精确控制。这使得关于皮克林乳液的各种基础科学问题得以解决。此外，嵌段共聚物纳米颗粒可用于在各种长度尺度上制备皮克林乳液，平均液滴直径范围从毫米到小于200纳米。
