A study of aggregation of sulphur particles in colloidal suspension of sulphur in water-methanol mixture using TEM and electron diffraction is reported. From the micrographs the aggregates formed have been found to be random and tenuous indicating a fractal structure. The electron diffraction patterns of the aggregates are used to study the mechanism of diffusion and reaction limited aggregation.

Acoustic non-linearity parameter B/A is calculated for five binary liquid mixtures using Tong and Dong equation along with the Flory’s statistical theory. Similar to other excess thermodynamical quantities an excess non-linearity parameter (B/A)^E is defined for binary liquid mixtures. The interactions in the liquid mixtures are explained on the basis of the excess non-linearity parameter.

The dielectric properties of nano-particles of ZnS have been studied over a temperature range from 300 to 525 K. The dielectric constant, dielectric loss and ac conductivity of the samples are larger than those of bulk ZnS crystals. Dielectric properties of composites consisting of nano-particles of Ag of different concentrations dispersed in nano-particles of ZnS have also been studied.