|Budget Amount *help
¥1,000,000 (Direct Cost : ¥1,000,000)
Fiscal Year 1999 : ¥500,000 (Direct Cost : ¥500,000)
Fiscal Year 1998 : ¥500,000 (Direct Cost : ¥500,000)
Since a polydisperse colloidal fluid is a complex system, it is inevitable to introduce an appropriate model which makes it possible to work essential properties of the system. Moreover, in order to improve understanding of the system it is important to obtain available expressions of physical quantities. In the present project, we employed the hard sphere Yukawa model for the system, and using the analytical MSA solution of the Ornstein-Zernike equation we succeeded to obtain analytical expressions for the static structure factor, the neutron (or light) scattering cross section and the thermodynamical quantities. The expressions obtained is useful and compact, and they prompt us to apply to the polydisperse fluids. Using the expressions, we actually worked the size and interaction polydispersity effects on observable quantities. The abstract of the work is as follows:
1. The interaction polydispersity effect on the structure factor describing the density fluctuation in the colloidal pa
rticle numbers is qualitatively the same effect as the size polydispersity has, but the former effect is weaker than the latter.
2. The interaction polydispersity has a characteristic effect on the isotherm of the equation of state near the critical point of the gas-liquid transition, and the directions of the size and interaction polydispersity-effects are opposite.
3. The measurable structure factor was investigated for the binary-pecies polydisperse fluid of colloidal hard spheres. It was found that the factor has a peculiar peak. The peak is very sensitive to the size polydispersity and changes gradually to the hump already known as the polydispersity increases. It was discussed that the peculiar structure is closely related to material distribution inside colloidal particles.
The interaction between colloidal particles in a solvent was worked. It was discussed that the solvent-mediated interaction could be longer-range and more important than the van der Waals interaction. However, this work needs further investigation and improvement.