title: Control of the optical properties of a star copolymer with a hyperbranched conjugated polymer core and poly(ethylene glycol) arms by self-assembly.
abstract: A self-assembly approach to tuning the optical properties of a star copolymer is reported herein. The star copolymer HCP-star-PEG with a hyperbranched conjugated polymer (HCP) core and many linear poly(ethylene glycol) (PEG) arms has been prepared successfully. The HCP core was synthesized by Wittig coupling of N-(n-hexyl)-3,6-diformylcarbazole and 1,3,5-bis[(triphenylphosphonio)methyl]benzene tribromide. Subsequently, the linear PEG arms were grafted onto the HCP core by acylhydrazone connection. It was found that the optical properties of HCP-star-PEG in chloroform solution changed on addition of acid. Both (1)H NMR and UV/Vis spectroscopic investigations confirmed that the variation of the optical properties was related to the complexation of the acid and the imine bond in the acylhydrazone group. HCP-star-PEG self-assembled into core-shell micelles in the mixed solvent of chloroform and acetonitrile, which affected the protonation of the imine bond. Therefore the optical properties of HCP-star-PEG can be readily controlled by self-assembly.
authors.affiliation: School of Chemistry and Chemical Engineering, State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, PR China.
authors.forename: Feng
authors.initials: F
authors.lastname: Qiu
authors.forename: Chunlai
authors.initials: C
authors.lastname: Tu
authors.forename: Yan
authors.initials: Y
authors.lastname: Chen
authors.forename: Yunfeng
authors.initials: Y
authors.lastname: Shi
authors.forename: Liang
authors.initials: L
authors.lastname: Song
authors.forename: Ruibing
authors.initials: R
authors.lastname: Wang
authors.forename: Xinyuan
authors.initials: X
authors.lastname: Zhu
authors.forename: Bangshang
authors.initials: B
authors.lastname: Zhu
authors.forename: Deyue
authors.initials: D
authors.lastname: Yan
authors.forename: Tao
authors.initials: T
authors.lastname: Han