Studies of Ordered Monodisperse Polystyrene Latexes. I. Shear Ultrasonic Measurements
Abstract
The rigidity G and the viscosity η of monodisperse polystyrene latexes were measured by the torsional quartz crystal method at 70 kHz, and an abrupt change in G and η was found at the order-disorder transition of the latexes. The torsional quartz crystal method was improved for measurements with aqueous conductive samples, and a careful calibration showed that G and η are obtained if the dielectric constant of the sample is known. In the ordered state of latex with a volume concentration of 9.3%, the apparent rigidity G and the viscosity η were about 1.5× 103 dyne/cm2 and 0.6 cp, respectively, while in the disordered state G was small and η was 0.95 cp. Ordered latex is a “crystal” formed by the screened Coulomb repulsion and is a good model not only for crystals but also for ordered structures in some biological systems.
- Publication:
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Japanese Journal of Applied Physics
- Pub Date:
- February 1978
- DOI:
- 10.1143/JJAP.17.305
- Bibcode:
- 1978JaJAP..17..305M