Next Article in Journal
Surface Roughening of Polystyrene and Poly(methyl methacrylate) in Ar/O2 Plasma Etching
Previous Article in Journal
Phase-Segregated Dendrigraft Copolymer Architectures
Previous Article in Special Issue
New Biocompatible Polyesters Derived from α-Amino Acids: Hydrolytic Degradation Behavior
Polymers 2010, 2(4), 623-648; doi:10.3390/polym2040623
Review

Photo-Induced Micellization of Block Copolymers

1,*  and 2
1 Department of Environmental and Life Sciences, Toyohashi University of Technology, 1-1 Hibarigaoka, Tempaku-cho, Toyohashi 441-8580, Japan 2 Department of Materials Science, Toyohashi University of Technology, 1-1 Hibarigaoka, Tempaku-cho, Toyohashi 441-8580, Japan
* Author to whom correspondence should be addressed.
Received: 30 September 2010 / Revised: 16 November 2010 / Accepted: 25 November 2010 / Published: 26 November 2010
(This article belongs to the Special Issue Advanced Polymer Architectures)
View Full-Text   |   Download PDF [448 KB, uploaded 26 November 2010]   |   Browse Figures
SciFeed

Abstract

We found novel photo-induced micellizations through photolysis, photoelectron transfer, and photo-Claisen rearrangement. The photolysis-induced micellization was attained using poly(4-tert-butoxystyrene)-block-polystyrene diblock copolymer (PBSt-b-PSt). BSt-b-PSt showed no self-assembly in dichloromethane and existed as isolated copolymers. Dynamic light scattering demonstrated that the copolymer produced spherical micelles in this solvent due to irradiation with a high-pressure mercury lamp in the presence of photo-acid generators, such as bis(alkylphenyl)iodonium hexafluorophosphate, diphenyliodonium hexafluorophosphate, and triphenylsulfonium triflate. The 1H NMR analysis confirmed that PBSt-b-PSt was converted into poly(4-vinylphenol)-block-PSt by the irradiation, resulting in self-assembly into micelles. The irradiation in the presence of the photo-acid generator also induced the micellization of poly(4-pyridinemethoxymethylstyrene)-block-polystyrene diblock copolymer (PPySt-b-PSt). Micellization occurred by electron transfer from the pyridine to the photo-acid generator in their excited states and provided monodispersed spherical micelles with cores of PPySt blocks. Further, the photo-Claisen rearrangement caused the micellization of poly(4-allyloxystyrene)-block-polystyrene diblock copolymer (PASt-b-PSt). Micellization was promoted in cyclohexane at room temperature without a catalyst. During micellization, the elimination of the allyl groups competitively occurred along with the photorearrangement of the 4-allyloxystyrene units into the 3-allyl-4-hydroxystyrene units.
Keywords: micellization; photolysis; photoelectron transfer; photo-claisen rearrangement; self-assembly; micelles; photo-acid generators; block copolymers micellization; photolysis; photoelectron transfer; photo-claisen rearrangement; self-assembly; micelles; photo-acid generators; block copolymers
This is an open access article distributed under the Creative Commons Attribution License (CC BY 3.0).

Share & Cite This Article

Further Mendeley | CiteULike
Export to BibTeX |
EndNote |
RIS
MDPI and ACS Style

Yoshida, E.; Kuwayama, S. Photo-Induced Micellization of Block Copolymers. Polymers 2010, 2, 623-648.

View more citation formats

Related Articles

Article Metrics

For more information on the journal, click here

Comments

[Return to top]
Polymers EISSN 2073-4360 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert