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Pressure‐ and Temperature‐Induced Phase Separation Transition in Homopolymer, Block Copolymer, and Protein in Water
Author(s) -
Shibayama Mitsuhiro,
Osaka Noboru
Publication year - 2010
Publication title -
macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 1022-1360
DOI - 10.1002/masy.201050514
Subject(s) - copolymer , materials science , phase transition , polymer chemistry , transition temperature , phase diagram , chemical engineering , small angle neutron scattering , neutron scattering , phase (matter) , polymer , chemistry , scattering , thermodynamics , organic chemistry , composite material , physics , superconductivity , optics , quantum mechanics , engineering
Effects of temperature, T , and pressure, P , on phase behavior and structure are discussed on three types of polymeric systems, i.e., a homopolymer (HP), a block copolymer (BC), and a protein (PR) in water. Due to the presence of hydrophobic groups, each system underwent a T ‐induced and P ‐induced phase separation by increasing T and P , respectively. However, these transitions are different from each other depending on their molecular structures. Small‐angle neutron scattering investigations revealed that HP showed a macrophase separation transition (MaST) with respect to both T and P . BC underwent a microphase separation transition (MiST) followed by a MaST with increasing T , while only a MaST was observed with increasing P . In the case of PR, on the other hand, T ‐induced and P ‐induced denaturations led to densely‐packed aggregates of oligomers and fractal‐aggregates of primary particles, respectively. The results from all systems indicated that hydrophobic interactions become insignificant at high pressures.