writer：Congguang Zheng, Yan Zhou, Huiqi Zhang*
keywords：Hairy hollow particles, Polymer micro- and nanoparticles
source：期刊
specific source：ACS APPLIED POLYMER MATERIALS 2020, 2(2), 220-233.
Issue time：2020年
A facile, general, and highly efficient strategy for preparing well-defined uniform hydrophilic hairy hollow functional polymer micro- and nanoparticles by combining RAFT polymerization techniques and the sacrificial template method is described. Two synthetic routes have been developed for this purpose. The first route involves one-pot synthesis of uniform "living" poly(methacrylic acid) (PMAA) micro/nanospheres with surface-bound dithioester groups via RAFT precipitation polymerization (RAFTPP), their successive grafting of cross-linked functional polymer layers and hydrophilic polymer brushes via surface-initiated RAFT (SI-RAFT) polymerization, and rapid etching of the PMAA core by simply washing the resulting core-shell-corona-structured particles with methanol. Alternatively, such hairy hollow polymer particles can also be prepared by synthesis of uniform "living" hollow polymer particles (through controlled grafting of cross-linked functional polymer layers onto "living" PMAA particles prepared via RAFTPP and selective etching of the PMAA core by methanol washing) and their grafting of hydrophilic polymer brushes via SI-RAFT polymerization. Uniform hairy hollow polymer particles with different hydrophilic polymer brushes and hydrodynamic diameters between 0.230 and 1.524 mu m were successfully prepared via above routes. In particular, they could be easily imparted with pH-/thermoresponsivity, glutathione-induced degradability, and fluorescence by simply incorporating corresponding stimuli-responsive or functional units into their shells or polymer brushes, and well-defined uniform multiple stimuli-responsive fluorescent and degradable hydrophilic hairy hollow polymer nanoparticles were readily obtained. The above strategy opens a versatile avenue for developing various advanced hierarchical hollow polymer particles of tailor-made structures and desired properties, which hold much promise in such applications as drug delivery and theranostics.