Статья

Light scattering and crossover critical phenomena in polymer solutions

Jaby JacobJ. Jacob, M. A. Anisimov, and J. V. Sengers ([email protected]) are with the Institute for Physical Science and Technology and the Department of Chemical Engineering, University of Maryland, College Park, Maryland 20742. ([email protected])М. А. АнисимовJ. Jacob, M. A. Anisimov, and J. V. Sengers ([email protected]) are with the Institute for Physical Science and Technology and the Department of Chemical Engineering, University of Maryland, College Park, Maryland 20742. ([email protected])J. V. SengersJ. Jacob, M. A. Anisimov, and J. V. Sengers ([email protected]) are with the Institute for Physical Science and Technology and the Department of Chemical Engineering, University of Maryland, College Park, Maryland 20742. ([email protected])V. A. DechaboJ. Jacob, M. A. Anisimov, and J. V. Sengers ([email protected]) are with the Institute for Physical Science and Technology and the Department of Chemical Engineering, University of Maryland, College Park, Maryland 20742. ([email protected])I. K. YudinJ. Jacob, M. A. Anisimov, and J. V. Sengers ([email protected]) are with the Institute for Physical Science and Technology and the Department of Chemical Engineering, University of Maryland, College Park, Maryland 20742. ([email protected])Robert W. GammonJ. Jacob, M. A. Anisimov, and J. V. Sengers ([email protected]) are with the Institute for Physical Science and Technology and the Department of Chemical Engineering, University of Maryland, College Park, Maryland 20742. ([email protected])

2001en

ABI

Аннотация

An accurate photon-correlation spectrometer capable of measuring scattered light at two fixed scattering angles simultaneously in the temperature range from 10 to 120 degrees C is described. For the detection of the correlation function of the scattered light both an original correlator (PhotoCor-SP) with a linear-time-scale channel spacing and an ALV GmbH correlator (Model ALV-5000) with a logarithmic-time-scale channel spacing are used. High-resolution static and dynamic light-scattering measurements near the critical point of a polystyrene solution were performed with this instrument. The static-intensity measurements reveal that the crossover from mean-field to Ising behavior occurs at a temperature at which the correlation length of the critical fluctuations becomes equal to the radius of gyration of the polymer molecule. We found that the wave-number dependence and the temperature dependence of the diffusion coefficient of the concentration fluctuations are not consistent with existing theory for critical dynamics in low-molecular-weight liquid mixtures.

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Идентификаторы

DOI: 10.1364/ao.40.004160

Цитирования и источники

Цитирований: 2Использованных источников: 0

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