title: Light scattering and luminescence studies on self-aggregation behavior of amphiphilic copolymer micelles.
abstract: The self-aggregation behavior of three amphiphilic graft copolymers, oligo(9,9-dihexyl)fluorence-graft-poly(ethylene oxide) (OHF-g-PEO), with different architectures was studied by dynamic and static light scattering (DLS and SLS) in combination with fluorescence spectroscopy and transmission electron microscopy (TEM). The formation of self-assembled polymeric micelles was confirmed by SLS and TEM. DLS and SLS analyses showed that the architecture of graft copolymers has a dramatic effect on critical aggregation concentration (CAC), micelle size distribution, apparent aggregation number (Nagg app), and apparent molecular weight of polymer aggregates (Mw,agg app). An architecture-dependent excimer emission, resulting from the pi-pi stacking of the oligofluorene backbones, was also observed from the photoluminescence spectra of the micelle aqueous solutions, which indicated a strong intermolecular interaction among the polymeric molecules. The excimer emission was further investigated by time-resolved fluorescence spectroscopy.
authors.affiliation: Institute of Materials Research & Engineering, 3 Research Link, Singapore 117602, Singapore.
authors.forename: Jun Hong
authors.initials: JH
authors.lastname: Yao
authors.forename: Khine Yi
authors.initials: KY
authors.lastname: Mya
authors.forename: Xu
authors.initials: X
authors.lastname: Li
authors.forename: Manoj
authors.initials: M
authors.lastname: Parameswaran
authors.forename: Qing-Hua
authors.initials: QH
authors.lastname: Xu
authors.forename: Kian Ping
authors.initials: KP
authors.lastname: Loh
authors.forename: Zhi-Kuan
authors.initials: ZK
authors.lastname: Chen
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry*; D005449:Fluorenes / Q000737:chemistry*; D049449:Luminescence; D008823:Micelles; D046529:Microscopy, Electron, Transmission; D011092:Polyethylene Glycols / Q000737:chemistry*; D012542:Scattering, Radiation; D012996:Solutions / Q000737:chemistry; D013050:Spectrometry, Fluorescence; D013499:Surface Properties; D014867:Water / Q000737:chemistry
chemical_list: D001672:Biocompatible Materials; D005449:Fluorenes; D008823:Micelles; D012996:Solutions; D014867:Water; D011092:Polyethylene Glycols