title: "Cross" Supermicelles via the Hierarchical Assembly of Amphiphilic Cylindrical Triblock Comicelles.
abstract: Self-assembled "cross" architectures are well-known in biological systems (as illustrated by chromosomes, for example); however, comparable synthetic structures are extremely rare. Herein we report an in depth study of the hierarchical assembly of the amphiphilic cylindrical P-H-P triblock comicelles with polar (P) coronal ends and a hydrophobic (H) central periphery in a selective solvent for the terminal segments which allows access to "cross" supermicelles under certain conditions. Well-defined P-H-P triblock comicelles M(PFS-b-PtBA)-b-M(PFS-b-PDMS)-b-M(PFS-b-PtBA) (M = micelle segment, PFS = polyferrocenyldimethylsilane, PtBA = poly(tert-butyl acrylate), and PDMS = polydimethylsiloxane) were created by the living crystallization-driven self-assembly (CDSA) method. By manipulating two factors in the supermicelles, namely the H segment-solvent interfacial energy (through the central H segment length, L1) and coronal steric effects (via the PtBA corona chain length in the P segment, L2 related to the degree of polymerization DP2) the aggregation of the triblock comicelles could be finely tuned. This allowed a phase-diagram to be constructed that can be extended to other triblock comicelles with different coronas on the central or end segment where "cross" supermicelles were exclusively formed under predicted conditions. Laser scanning confocal microscopy (LSCM) analysis of dye-labeled "cross" supermicelles, and block "cross" supermicelles formed by addition of a different unimer to the arm termini, provided complementary characterization to transmission electron microscopy (TEM) and dynamic light scattering (DLS) and confirmed the existence of these "cross" supermicelles as kinetically stable, micron-size colloidally stable structures in solution.
authors.affiliation: School of Chemistry, University of Bristol , Bristol BS8 1TS, United Kingdom.
authors.forename: Xiaoyu
authors.initials: X
authors.lastname: Li
authors.affiliation: School of Chemistry, University of Bristol , Bristol BS8 1TS, United Kingdom.
authors.forename: Yang
authors.initials: Y
authors.lastname: Gao
authors.affiliation: School of Chemistry, University of Bristol , Bristol BS8 1TS, United Kingdom.
authors.forename: Charlotte E
authors.initials: CE
authors.lastname: Boott
authors.affiliation: School of Chemistry, University of Bristol , Bristol BS8 1TS, United Kingdom.
authors.forename: Dominic W
authors.initials: DW
authors.lastname: Hayward
authors.affiliation: School of Chemistry, University of Bristol , Bristol BS8 1TS, United Kingdom.
authors.forename: Robert
authors.initials: R
authors.lastname: Harniman
authors.affiliation: School of Chemistry, University of Bristol , Bristol BS8 1TS, United Kingdom.
authors.forename: George R
authors.initials: GR
authors.lastname: Whittell
authors.affiliation: School of Physics, University of Bristol , Bristol BS8 1TS, United Kingdom.
authors.forename: Robert M
authors.initials: RM
authors.lastname: Richardson
authors.affiliation: Department of Chemistry, University of Toronto , Toronto, Ontario M5S 3H6, Canada.
authors.forename: Mitchell A
authors.initials: MA
authors.lastname: Winnik
authors.affiliation: School of Chemistry, University of Bristol , Bristol BS8 1TS, United Kingdom.
authors.forename: Ian
authors.initials: I
authors.lastname: Manners