title: Crossover from stretched to compressed exponential relaxations in a polymer-based sponge phase.
abstract: 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.
authors.affiliation: Department of Physics, Yale University, New Haven, Connecticut 06511, USA.
authors.forename: P
authors.initials: P
authors.lastname: Falus
authors.forename: M A
authors.initials: MA
authors.lastname: Borthwick
authors.forename: S
authors.initials: S
authors.lastname: Narayanan
authors.forename: A R
authors.initials: AR
authors.lastname: Sandy
authors.forename: S G J
authors.initials: SG
authors.lastname: Mochrie