Arun Kumar Sharma*, Meenakshi Saxena and Rashmi Sharma Pages 123 - 137 ( 15 )
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.
CMC, Cu(II) surfactant, edible oils, soap-solvent interaction, urea, viscosity.
Department of Chemistry, Govt. P.G. College, Jhalawar-326001, Rajasthan, Department of Chemistry, S.D. Govt. College, Beawar - 305901, Rajasthan, Department of Chemistry, S.P.C. Govt. College, Ajmer - 305001, Rajasthan