Ajaya Bhattarai

Effect of Methanol on Viscosity of Aqueous Solutions of Cationic Surfactants at 298.15 to 323.15 K

Viscosity measurements have been made to the solutions of dodecyltrimethylammonium bromide (DTAB) and cetyltrimethylammonium bromide (CTAB) in 0.10, 0.20, 0.30, and 0.40 volume fractions of methanol in methanol-water mixed solvent media at 298.15, 308.15, 318.15, and 323.25 K. Critical micelle concentration (CMC) values have been determined. From relative viscosity for surfactant solutions, related viscosity B coefficients are calculated and the values are interpreted in terms of solute-solvent interactions.

Microscopic Structure of NaCd Compound Forming Binary Molten Alloys

A simple statistical mechanical theory based on compound formation model (compound Aμ Bv formed by the preferential arrangement of A and B constituent atoms of the alloy AB, μA + νB ≒ Aμ Bv) has been used to investigate the phenomena of compound formation in NaCd liquid alloys through the study of concentration fluctuation in the long wavelength region [Scc(0)] and chemical short range order parameter (α1). The study explains the observed asymmetry successfully and suggest the existence of Cd2Na complex in the melt. The tendency of compound has been found to be weak. A tendency of inversion from segregation to order although very small, has been observed, in NaCd liquid alloys.