Shear- and Temperature-Dependent Viscosity Behavior of Two Phosphonium-Based Ionic Liquids and Surfactant Triton X-100 and Their Biocidal Activities

Abstract

The viscosity of ionic liquids triisobutyl(methyl)phosphonium tosylate (IL-1) and trihexyl(tetradecyl)phosphonium bis-2,4,4-(trimethylpentyl)phosphinate (IL-2) were studied along with the surfactant p-tertoctylphenoxypolyoxyethylene(9.5)ether (Triton X-100 or TX-100). These fluids are non-Newtonian and witnessed mostly shear thinning and thickening behavior studied over a wide range of shear rate ((0.12 to 5.63) s −1 ) in the temperature range of (293 to 333) K. The activation parameters ΔH* (enthalpy of activation), ΔG* (free energy of activation), ΔS* (entropy of activation), and ΔC p * (change in heat capacity) values for their viscous flow were evaluated and presented. The magnitudes of the parameters were fairly large. The values of ΔG* increased with temperature, whereas the rest decreased. The values of ΔH* and ΔS* nicely compensated each other. Microbiological activities of IL-1, IL-2, and TX-100 were examined against two bacterial strains Bacillus subtilis (gram positive) and Escherichia coli (gram negative) by measuring the diameter of the inhibition zone ("diz"); both the ILs exhibited greater antimicrobial activity than that of TX-100.

Rheological properties of {[bmim]PF6+methanol} mixtures at different temperatures, shear rates and compositions

“…[27] (for pure [bmim]PF 6 ) show, the amount of variation of the viscosity versus shear rate decreases from pure ionic liquid to pure alcohol. In fact, while pure ionic liquid shows moderate non-Newtonian behavior (similar to that of observed for pure ILs in some previous works [27,46,47]), adding alcohol causes a gradual change from non-Newtonian to Newtonian behavior. To give a better presentation of the sheardependent of these IL-alcohol mixtures, the variation of the viscosity versus shear rate has been shown in the figures at 30°C as an example.…”

“…It may be due to the orientation differences of the molecules of liquids under the influence of stress. The viscosity of these mixtures depends on their geometry (molecular size) in the form of ion-pairs and their packing and orientation in the bulk [46].…”

“…Mukherjee et al [46] showed that the activation parameters of fluids can be obtained via following relations. Considering the energy of activation (E a ) equivalent to the Gibbs free energy of activation (ΔG ⁎ ), the Arrhenius form of viscosity relations can be written as, where, ΔS*, h, N, and V are the activation entropy, Planck's constant, Avogadro's number, and the molar volume of the liquid, respectively.…”

Phase behavior of the surfactant ionic liquid trihexyltetradecylphosphonium bis(2,4,4-trimethylpentyl)phosphinate with water and dodecane

“…Exclusively at very low shear rates, a non-Newtonian character has been found. This behavior has been previously shown in the literature for other phosphonium ionic liquids [42]. Once it was proven that [P 6 6 6 14 ][(iOc) 2 PO 2 ] can be considered as a Newtonian liquid, all viscosities for pure liquids and mixtures in the ternary system (water + ionic liquid + n-dodecane) were measured using an Ubbelohde microviscometer.…”

Aggregation behavior of Triton X-114 and Tween 80 at various temperatures and concentrations studied by density and viscosity measurements

“…This confirms that above C = 10 -3 M water is loosely bound to Tween 80 molecules and/or its micelles. In the case of TX114, the situation is more complicated because this energy also decreases but only in the range of For better explanation viscosity influence on the rate of mass transport in the studied solutions, the activation thermodynamic parameters, i.e., DH * (enthalpy of activation) and DC p * (change in heat capacity of activation), were also calculated from the relationships proposed by Mukherjee et al [43]:…”