Aggregation behavior and thermodynamic properties of the mixture of sodium carboxymethyl cellulose and cetyltrimethylammonium bromide in numerous temperatures and mixed solvents

Interaction of sodium carboxymethylcellulose (SCMC) with cetyltrimethylammonium bromide (CTAB; cationic in nature) in H2O and additives (alcohols and diols) media has been investigated using conductivity technique. The micellar parameters such as critical micelle concentration (cmc), fraction of counter ion binding (β), thermodynamic parameters, transfer properties, and enthalpy-entropy compensation parameters of CTAB + SCMC mixture have been assessed in water and aq. alcohols/diols media. One cmc value was achieved for CTAB + SCMC mixtures in the entire circumstances and the attendance of SCMC disfavors the CTAB micellization. The cmc values were obtained to be greater in alcohols and diols media compared to H2O medium. The cmc values also exhibit a dependency on the solvent composition and temperature variation. In all the cases, the ΔG 0 m values were achieved to be negative which signifying the spontaneous formation of micelles while the extent of spontaneity is decreased in alcohols and diols media. Both the ΔH 0 m and ΔS 0 m reveal that hydrophobic, ion-dipole as well as electrostatic interactions are the proposed binding forces between CTAB and SCMC. The compensation parameters (ΔH 0* m and T c ) are in decent agreement with the biological fluid.

Ionic effects on Supramolecular Hosts: Solvation and Counter-ion Binding in Polar Media

For the progress of synthetic supramolecular chemistry in aqueous solution the design of host molecules soluble in this medium is essential. A possible route is the introduction of ionic residues,...

Aggregation Behaviours of Surface-Active Ionic Liquids 1-Alkyl-3-methylimidazolium Bis(2-ethylhexyl)sulfosuccinate

The systematic investigation of the aggregation behaviours of newly synthesised surface-active ionic liquids 1-alkyl-3-methylimidazolium bis(2-ethylhexyl)sulfosuccinate ([Cnmim][AOT], n = 2, 3, 5, 6, 7) by various techniques is reported. The critical aggregation concentrations (CACs) and the standard Gibbs free energies of aggregation () were determined from measurements on conductivity, fluorescence, and surface tension, which suggested a stronger self-assembly ability in the bulk solution for [Cnmim][AOT] surfactants with longer alkyl chain cations. An interesting structure transition driven by the penetration of the imidazolium cation into the aggregate when n > 4 was found by analysis of the variations of the values of CAC, , the degree of counter ion binding (β), and the micropolarity (I1/I3) immediately after the CAC with changing alkyl chain length of the imidazolium cation, which was further confirmed by 1H NMR measurements.

Optical properties of prodigiosin and obatoclax: action spectroscopy and theoretical calculations

Action spectroscopy and first principles calculations are performed to characterize the optical properties of prodigiosin, and its sensibility to protonation, counter-ion binding, and isomerization.

Effect of Biologically Significant Metal Complex Additives on the Micellar Properties of SDS

The effect of some biologically significant transition metal complexes such as [Fe(bpy)Cl4] [bpy-H], [Co(bpy)(phen)2](NO3)2·2H2O, [Fe(PDCl4][PD-H], [Cu(L)(NO3)2], [Cu(phen)2] Cl2·2H2O and [Cu(PD)(phen)2](NO3)2·2H2O (L=3,14-diethyl-2,6,13,17-tetraazatricyclo (16,4,07,12)docosane, bpy=2,2?-bipyridine, PD =1,10-phenanthroline-5,6-dione, phen=1,10-phenanthroline) on the critical micelle concentration (CMC) of an anionic surfactant, sodium dodecyl sulfate (SDS) were studied by conductance measurement method. The investigation was performed in the additives concentration ranging from 2.0 × 10-4 M to 8.0 × 10-4 M and at temperature ranging from 20°C to 35°C with an interval of 5°C. Different micellar parameters such as CMC, degree of counter ion dissociation (?), degrees of counter ion binding (f), binding constant (Kb) as well as thermodynamic parameters were determined using the conductivity data. © 2014 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved. doi: http://dx.doi.org/10.3329/jsr.v6i3.17761 J. Sci. Res. 6 (3), 497-508 (2014)