title: Phase transition and phase transformation in block copolymer nanoparticles.
abstract: Block copolymer nanopaticles were prepared from the mixture solutions containing good/poor solvents by a simple evaporation process. The block copolymers formed disorder, unidirectionally stacked lamellar, and onion-like structures in nanoparticles depending on preparation temperatures. Thermal annealing induced the disorder-order phase transition and order-order phase transformation in the block copolymer nanoparticles, even though the annealing temperature is lower than the of one polymer segment. The unusual thermal behaviors suggest that the glass transition temperature of the block copolymer is decreased by the effect of nanoparticle, whose surface areas are larger than their volumes.
authors.affiliation: WPI Research Center, Advanced Institute for Materials Research (WPI-AIMR), Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan. higuchi@mail.tagen.tohoku.ac.jp.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Higuchi
authors.forename: Kiwamu
authors.initials: K
authors.lastname: Motoyoshi
authors.forename: Hidekazu
authors.initials: H
authors.lastname: Sugimori
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Jinnai
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yabu
authors.forename: Masatsugu
authors.initials: M
authors.lastname: Shimomura