Temperature-dependent aggregation of bio-surfactants in aqueous solutions of galactose and lactose: Volumetric and viscometric approach

Determination of Acoustical Parameters of Aqueous Solution of Kolliphors Binary Mixtures Using Density, Speed of Sound, Viscosity, and Surface Tension Measurements

“…Figure shows that MCE values increase for all solutions when C is higher than 10 −3 M due to formation of micelles. Values of MCE for RH40 molecules are larger consistent with smaller viscous relaxation time ( τ ) evaluated based on (Chauchan et al, ): …”

“…The synergetic effect between different surfactant molecules is evidenced by the smaller values of L f at a given concentration for all mixtures compared to that of single surfactants. Comparison of the distance between two molecules ( L f ) and available volume of surfactant molecule in the solution ( V a ) (Table ) with the values of free volume ( V f ), that is the average volume in which a single molecule can move inside a hypothetical shell due to surrounding molecules repulsion seemed worthwhile (Chauchan et al, ). The free volume also referred to as a void space between molecules caused by irregular molecular packing, and can be calculated using the formula (Chauchan et al, ; Chauhan and Sharma, ): where K ′ = 4.28 × 10 9 is a constant independent of liquid nature.…”

Interactional Behavior of Sodium Cholate and Sodium Deoxycholate in the Presence of Ceftriaxone Sodium: Volumetric, Compressibility, Viscometric, and Proton Nuclear Magnetic Resonance Studies

“…This reveal that at lower concentration, ionic and hydrophilic–hydrophilic interactions play their role, while at higher concentrations, these interactions are dominated by hydrophobic–hydrophobic interactions . The curvilinear nature of the variation in V φ has also been supported in earlier reports on bile salts ,, as well as for the conventional surfactant. , From V φ values, it can also be observed that the temperature and content of Cft-Na increases V φ values, signifying the manifestation of solute–solvent interactions with addition of drug, which enhances with temperature due to destructive overlap . Moreover, smaller V φ values in the case of NaDC as compared to NaC (within the experimental error) are obviously due to lack of one −OH group in NaDC, thereby causing more close packing of water molecules around the ionic center of NaDC, which strengthens the fact of its stronger structure-making ability than NaC.…”

“…This reveal that at lower concentration, ionic and hydrophilic− hydrophilic interactions play their role, while at higher concentrations, these interactions are dominated by hydrophobic−hydrophobic interactions. 29 The curvilinear nature of the variation in V φ has also been supported in earlier reports on bile salts 6,10,30 as well as for the conventional surfactant. 31,32 From V φ values, it can also be observed that the temperature and content of Cft-Na increases V φ values, signifying the manifestation of solute−solvent interactions with addition of drug, which enhances with temperature due to destructive overlap.…”