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Title: Pressure-Induced Phase Transitions of Hydrophobically Solvated Block-Copolymer Solutions

Abstract

The structures of poly(2-(2-ethoxy)ethoxyethyl vinyl ether)-block-poly(2-methoxyethyl vinyl ether) in D{sub 2}O have been investigated with small-angle neutron scattering (SANS) as a function of temperature T and pressure P. At ambient pressure, the solution underwent a two-step transition at 40 and 65 deg. C, both of which were convex-upward functions of P having a maximum around P{sub 0}{approx_equal}150 MPa. The first transition was assigned to a microphase separation to form a bcc structure, and the second was to a macrophase separation. Pressurizing at 28 deg. C resulted in a macrophase separation with divergence at 350 MPa. At 45 deg. C, a reentrant microphase separation was observed by increasing P. Differences in the states of hydrophobic solvation in the low (P<P{sub 0}) and high pressure regions (P>P{sub 0}) are discussed based on the SANS structure factors.

Authors:
;  [1]
  1. Neutron Science Laboratory, Institute for Solid State Physics, University of Tokyo, Tokai, Ibaraki 319-1106 (Japan)
Publication Date:
OSTI Identifier:
20777013
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review Letters; Journal Volume: 96; Journal Issue: 4; Other Information: DOI: 10.1103/PhysRevLett.96.048303; (c) 2006 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; BCC LATTICES; COPOLYMERS; ETHERS; HEAVY WATER; NEUTRON DIFFRACTION; PHASE TRANSFORMATIONS; PRECIPITATION; PRESSURE DEPENDENCE; PRESSURE RANGE MEGA PA 100-1000; PRESSURIZATION; SMALL ANGLE SCATTERING; SOLUTIONS; SOLVATION; STRUCTURE FACTORS; TEMPERATURE DEPENDENCE; TEMPERATURE RANGE 0273-0400 K

Citation Formats

Osaka, Noboru, and Shibayama, Mitsuhiro. Pressure-Induced Phase Transitions of Hydrophobically Solvated Block-Copolymer Solutions. United States: N. p., 2006. Web. doi:10.1103/PhysRevLett.96.048303.
Osaka, Noboru, & Shibayama, Mitsuhiro. Pressure-Induced Phase Transitions of Hydrophobically Solvated Block-Copolymer Solutions. United States. doi:10.1103/PhysRevLett.96.048303.
Osaka, Noboru, and Shibayama, Mitsuhiro. Fri . "Pressure-Induced Phase Transitions of Hydrophobically Solvated Block-Copolymer Solutions". United States. doi:10.1103/PhysRevLett.96.048303.
@article{osti_20777013,
title = {Pressure-Induced Phase Transitions of Hydrophobically Solvated Block-Copolymer Solutions},
author = {Osaka, Noboru and Shibayama, Mitsuhiro},
abstractNote = {The structures of poly(2-(2-ethoxy)ethoxyethyl vinyl ether)-block-poly(2-methoxyethyl vinyl ether) in D{sub 2}O have been investigated with small-angle neutron scattering (SANS) as a function of temperature T and pressure P. At ambient pressure, the solution underwent a two-step transition at 40 and 65 deg. C, both of which were convex-upward functions of P having a maximum around P{sub 0}{approx_equal}150 MPa. The first transition was assigned to a microphase separation to form a bcc structure, and the second was to a macrophase separation. Pressurizing at 28 deg. C resulted in a macrophase separation with divergence at 350 MPa. At 45 deg. C, a reentrant microphase separation was observed by increasing P. Differences in the states of hydrophobic solvation in the low (P<P{sub 0}) and high pressure regions (P>P{sub 0}) are discussed based on the SANS structure factors.},
doi = {10.1103/PhysRevLett.96.048303},
journal = {Physical Review Letters},
number = 4,
volume = 96,
place = {United States},
year = {Fri Feb 03 00:00:00 EST 2006},
month = {Fri Feb 03 00:00:00 EST 2006}
}