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Formation of homogeneous gel‐like phases by mixed triblock copolymer micelles in aqueous solution: FCC to BCC phase transition
Author(s) -
Liu T.,
Chu B.
Publication year - 2000
Publication title -
journal of applied crystallography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.429
H-Index - 162
ISSN - 1600-5767
DOI - 10.1107/s0021889899013369
Subject(s) - small angle x ray scattering , copolymer , micelle , aqueous solution , homogeneous , materials science , phase (matter) , hexagonal crystal system , polymer , crystallography , hexagonal phase , scattering , polymer chemistry , chemistry , thermodynamics , organic chemistry , physics , optics , composite material
The phase behavior of mixed block copolymers E 99 P 69 E 99 and E 45 B 14 E 45 (with E, P and B being oxyethylene, oxypropylene and oxybutylene, respectively) in aqueous solution is reported for the first time. Homogeneous gel‐like structures, formed by the ordered packing of mixed block copolymer micelles, were studied by small‐angle X‐ray scattering (SAXS). Four different single phases could be identified: mixed solution, body‐centered cubic (bcc), face‐centered cubic (fcc) and hexagonal. Two fcc to bcc transitions occurred by increasing 99 P 69 E 99 concentration or by adding a small amount of E 45 B 14 E 45 chains to the 99 P 69 E 99 /water system while keeping the total polymer concentration constant at around 30 wt%.