12 research outputs found
Diffusive motion in aqueous solutions
857-861The interest
in diffusion phenomena arises from both applied and fundamental points of view
and in recent years, there has been some spectacular development in this study both
theoretically and experimentally. Inelastic neutron scattering, NMR, optical
and above all radioactive tracer techniques have accumulated important information about the
migration of ions, or molecules through a maze of molecules. The difficulty in
the study of liquids lies in the fact that, kinetic energy and potential energy
of the constituent particles in a liquid are comparable and both must be taken
into account to calculate any property, which is to be compared with observed
results. In general, by employing techniques which increase the thermal motion of the constituent
particles or by varying the composition of the binary and ternary systems, much
information can be gathered about liquids and, in this respect, diffusion study
in liquids is an important tool. It is very interesting and very
important to
observe the change in diffusion coefficient in some aqueous solution with the
introduction of known amounts of some other salts or acids. This study of
coupled flow has been undertaken by several groups of workers. A sliding cell
method based on radioactive tracer technique has been developed in the
laboratory of the author and it has been used to measure diffusion coefficient
in H3PO4-H2O system containing different
amount of salts of this weak acid. Different radioactive isotopes like Na-22, Na-24,
Hg-203, Ga-72, Cs-134, Cs-137, TI-204, P-32 etc., have been used in the laboratory
for diffusion measurements in different systems. Irreversible thermodynamical
principles have been applied to explain the observed results. Both H2O
and D2O have been employed as solvents and the breaking of their
structures with the
introduction of salts have
been explained.</span