title: Spherical polymer brushes in solvents of variable quality: an experimental insight by TEM imaging.
abstract: The spherical micelle and vesicle composed of [PW12O40](3-) and poly(styrene-b-4-vinylpyridinium methyl iodide) are regarded as a model system to study spherical polymer brushes (SPBs) in solvents of various quality. The pure repulsions occur for the brush chains in the chloroform solution and chloroform/methanol mixture with a methanol volume ratio of 9.1%, where the grafted polystyrene chains have a relatively extended conformation. Further increase in the methanol concentrations leads to the presence of the intra/inter-brush van der Waals attractions. Transmission electron microscopy studies show that there is a coexistence of isolated and oligomeric SPBs and multi-SPB aggregates (MSAs) with the methanol content from 17% to 23%. Only MSAs are detected with the increasing methanol content. Both the corona and core shrink significantly in the isolated and oligomeric SPBs and MSAs. The full interpenetration of the grafted chains is observed between the cores in the oligomeric SPBs and MSAs.
authors.affiliation: Key Laboratory of Nonferrous Metals Chemistry and Resources Utilization of Gansu Province, State Key Laboratory of Applied Organic Chemistry, and College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou City, Gansu Province, China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Zhang
authors.forename: Yin
authors.initials: Y
authors.lastname: Liao
authors.forename: Lipeng
authors.initials: L
authors.lastname: He
authors.forename: Weifeng
authors.initials: W
authors.lastname: Bu
mesh_terms: D002725:Chloroform / Q000737:chemistry*; D000432:Methanol / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission; D010316:Particle Size; D011108:Polymers / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry; D013499:Surface Properties
chemical_list: D011108:Polymers; D012997:Solvents; D002725:Chloroform; D000432:Methanol