Crossover from stretched to compressed exponential relaxations in a polymer-based sponge phase.
X-ray photon correlation spectroscopy was used to characterize the wave vector- and temperature-dependent dynamics of spontaneous thermal fluctuations in a sponge (L3) phase that occurs in a blend of a symmetric poly(styrene-ethylene/butylene-styrene) triblock copolymer with a polystyrene homopolymer. Measurements of the intermediate scattering function reveal a crossover from stretched- to compressed-exponential relaxations as the temperature is lowered from 180 to 120 degrees C.
Falus
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Department of Physics, Yale University, New Haven, Connecticut 06511, USA.
Borthwick
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Narayanan
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Sandy
A R
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Mochrie
S G J
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