Background: Of-late researches in colloid chemistry are becoming increasingly
important in various branches of chemistry, industry, medicine and allied fields. Copper
surfactants derived from various edible oils provide an interesting area of investigation pertaining
to its fundamental information regarding their colloid-chemical behaviour. Copper
(II) soaps and their urea complexes in polar and non-polar solvents have gained considerable
popularity due to their immense use and widespread applications such as wood preservation,
foaming, wetting, biocidal, pesticidal activities, fungicidal, detergency, emulsification,
paints, lubrication etc.
Objective: Present work has been initiated with a view to obtain a profile due to the nature
and structure of copper soap and their urea complexes with long chain fatty acids in polar
and non-polar solvent, which have great significance in explaining their characteristics under
different conditions. The objective of the present work is study of micellar characterizations
of copper soap and their urea complexes in polar (methanol) and non-polar (benzene)
solvents of varying composition and subsequent determinations of CMC using physical
properties such as, viscosity. This will provide fundamental information regarding
their colloid chemical behavior.
Methods: The density, molar volume, viscosity, specific viscosity, and fluidity of Cu (II)
soap- urea complexes derived from various edible oils in a benzene-methanol solvent system
have been determined at a constant temperature of 303.15 K.
Results: The results were used to determine the critical micelle concentration (CMC), soap
complex-solvent interactions and the effect of chain length of the surfactant molecules on
various parameters. The values of the CMC in the higher volume percent of methanol are
higher than those of the lower volume percent of methanol. The values of CMC for these
complexes are following the order:
CSoU>CSeU> CGU > CMU
This shows that there is a decrease in the CMC values with an increase of the average molecular
weight of the complex. The conclusions with regard to solute-solute and solutesolvent
interactions have been discussed in terms of the well-known Moulik’s and Jones-
Dole equations. The effect of surfactant concentration on the viscosity of the solution in
the solvent mixtures has been discussed. The observations suggested that the solvent structure
breaking effect by the solute on the solvent molecules is more prominent above the
CMC as compared to below the CMC.
Conclusion: The vital information about the micellar behavior of synthesized molecules as
a solute and their interactions with different solvents will plays an important role in various
industrial and biological applications.