title: Pathway toward large two-dimensional hexagonally patterned colloidal nanosheets in solution.
abstract: We report the solution self-assembly of an ABC block terpolymer consisting of a polystyrene-block-poly(ethylene oxide) (PS-b-PEO) diblock copolymer tail tethered to a fluorinated polyhedral oligomeric silsesquioxane (FPOSS) cage in 1,4-dioxane/water. With increasing water content, abundant unconventional morphologies, including circular cylinders, two-dimensional hexagonally patterned colloidal nanosheets, and laterally patterned vesicles, are sequentially observed. The formation of toroids is dominated by two competing free energies: the end-cap energy of cylinders and the bending energy to form the circular structures. Incorporating the superhydrophobic FPOSS cages enhances the end-cap energy and promotes toroid formation. Lateral aggregation and fusion of the cylinders results in primitive nanosheets that are stabilized by the thicker rims to partially release the rim-cap energy. Rearrangement of the parallel-aligned FPOSS cylindrical cores generates hexagonally patterned nanosheets. Further increasing the water content induces the formation of vesicles with nanopatterned walls.
authors.affiliation: Department of Polymer Science, The University of Akron , Akron, Ohio 44325-3909, United States.
authors.forename: Bo
authors.initials: B
authors.lastname: Ni
authors.forename: Mingjun
authors.initials: M
authors.lastname: Huang
authors.forename: Ziran
authors.initials: Z
authors.lastname: Chen
authors.forename: Yingchao
authors.initials: Y
authors.lastname: Chen
authors.forename: Chih-Hao
authors.initials: CH
authors.lastname: Hsu
authors.forename: Yiwen
authors.initials: Y
authors.lastname: Li
authors.forename: Darrin
authors.initials: D
authors.lastname: Pochan
authors.forename: Wen-Bin
authors.initials: WB
authors.lastname: Zhang
authors.forename: Stephen Z D
authors.initials: SZ
authors.lastname: Cheng
authors.forename: Xue-Hui
authors.initials: XH
authors.lastname: Dong
mesh_terms: D003102:Colloids / Q000737:chemistry*; D004146:Dioxanes / Q000737:chemistry; D054879:Halogenation; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D017646:Organosilicon Compounds / Q000737:chemistry*; D011092:Polyethylene Glycols / Q000737:chemistry*; D011137:Polystyrenes / Q000737:chemistry*; D012996:Solutions; D014867:Water / Q000737:chemistry
chemical_list: D003102:Colloids; D004146:Dioxanes; D017646:Organosilicon Compounds; D011137:Polystyrenes; D012996:Solutions; C521417:polyhedraloligosilsesquioxane; C541965:polystyrene-b-poly(ethylene oxide); D014867:Water; D011092:Polyethylene Glycols; C025223:1,4-dioxane