Publikace detail

Time-resolved Small-angle X-ray Scattering Study of the Kinetics of Disorder-order Transition in a Triblock Copolymer in a Selective Solvent for the Middle Block

Autoři: Nie H. | Bansil Rama | Ludwig Karl | Steinhart Miloš

Rok: 2003

Druh publikace: článek v odborném periodiku

Název zdroje: Macromolecules

Název nakladatele: American Chemical Society

Místo vydání: Washington

Strana od-do: 8097-8106

Tituly:

Jazyk	Název	Abstrakt	Klíčová slova
cze	Time-resolved Small-angle X-ray Scattering Study of the Kinetics of Disorder-order Transition in a Triblock Copolymer in a Selective Solvent for the Middle Block	The kinetics of the disorder-order transition (ODT) in a triblock of polystyrene (PS) and poly(ethylene-co-butylene) (PEB), in mineral oil, a selective solvent for the middle PEB block, was followed by time-resolved SAXS using both temperature ramp and rapid temperature quench techniques. Data analysis, using the Percus-Yevick interacting hard-sphere model plus Gaussians for the Bragg peaks in the ordered body-centered-cubic (bcc) state, shows that the core radius R-c, the hard-sphere volume fraction phi, and their interaction radius R-hs increased with decreasing temperature in the disordered state. At the ODT, phi reaches a maximum and R-c and phi change on ordering. The kinetics exhibits two stages corresponding to temperature equilibration and supercooling of the micellar fluid followed by nucleation and growth of the ordered state. The induction time for the onset of the second stage shows a minimum around the glass transition of the polystyrene cores.	asymetrické diblokové kopolymery;fázové chování;nukleace;gely;¨morfologie
eng	Time-resolved Small-angle X-ray Scattering Study of the Kinetics of Disorder-order Transition in a Triblock Copolymer in a Selective Solvent for the Middle Block	The kinetics of the disorder-order transition (ODT) in a triblock of polystyrene (PS) and poly(ethylene-co-butylene) (PEB), in mineral oil, a selective solvent for the middle PEB block, was followed by time-resolved SAXS using both temperature ramp and rapid temperature quench techniques. Data analysis, using the Percus-Yevick interacting hard-sphere model plus Gaussians for the Bragg peaks in the ordered body-centered-cubic (bcc) state, shows that the core radius R-c, the hard-sphere volume fraction phi, and their interaction radius R-hs increased with decreasing temperature in the disordered state. At the ODT, phi reaches a maximum and R-c and phi change on ordering. The kinetics exhibits two stages corresponding to temperature equilibration and supercooling of the micellar fluid followed by nucleation and growth of the ordered state. The induction time for the onset of the second stage shows a minimum around the glass transition of the polystyrene cores.	ASYMMETRIC DIBLOCK COPOLYMERS;PHASE-BEHAVIOR;CONCENTRATED-SOLUTIONS;VARYING SELECTIVITY;DYNAMICS;STYRENE;NUCLEATION;MORPHOLOGY;GELS;MICRODOMAINS

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