Department of Chemistry, Key Lab of Organic Optoelectronics & Molecular Engineering, Tsinghua University, Beijing, 100084, P. R. China.
Department of Chemistry, Waterloo Institute for Nanotechnology (WIN), University of Waterloo, Waterloo, N2L 3G1, Canada.
Angew Chem Int Ed Engl. 2017 Dec 22;56(52):16541-16545. doi: 10.1002/anie.201709129. Epub 2017 Nov 30.
A one-step synthesis of nanotubes by RAFT dispersion polymerization of cyclodextrin/styrene (CD/St) complexes directly in water is presented. The resulted amphiphilic PEG-b-PS diblock copolymers self-assemble in situ into nanoparticles with various morphologies. Spheres, worms, lamellae, and nanotubes were controllably obtained. Because of the complexation, the swelling degree of polystyrene (PS) blocks by free St is limited, resulting in limited mobility of PS chains. Consequently, kinetically trapped lamellae and nanotubes were obtained instead of spherical vesicles. During the formation of nanotubes, small vesicles first formed at the ends of the tape-like lamellae, then grew and fused into nanotubes with a limited chain rearrangement. The introduction of a host-guest interaction based on CDs enables the aqueous dispersion polymerization of water-immiscible monomers, and produces kinetically trapped nanostructures, which could be a powerful technique for nanomaterials synthesis.
通过 RAFT 分散聚合直接在水中将环糊精/苯乙烯（CD/St）复合物一步合成纳米管。所得的两亲性 PEG-b-PS 嵌段共聚物在原位自组装成具有各种形态的纳米颗粒。可控地得到了球体、蠕虫、层状和纳米管。由于复合物的存在，自由 St 对聚苯乙烯（PS）链段的溶胀程度受到限制，导致 PS 链的迁移性有限。因此，得到的是动力学捕获的层状和纳米管，而不是球形囊泡。在纳米管的形成过程中，小囊泡首先在带状层状结构的两端形成，然后生长并融合成具有有限链重排的纳米管。基于 CD 的主体-客体相互作用的引入使得水不混溶单体的水分散聚合成为可能，并产生了动力学捕获的纳米结构，这可能是一种用于纳米材料合成的强大技术。
