Evaluation of viscosity measurements of dilute solutions of ionic surfactants forming rod-shaped micelles

Colloid & Polymer Science

1998

The physicochemical properties of a mixed surfactant system were studied under various conditions. The surfactants were anionic sodium dodecyl benzene sulfonate and nonionic Triton X 100. Variation of specific conductivity with concentration was used to determine the critical micelle concentration of anionic as well as the mixed surfactants. Iodine solubilization method was used to determine the CMC of the nonionic surfactant. The interaction parameter between the surfactant molecules were calculated.The wetting, foaming and detergent properties of mixed surfactant systems were studied. The variation of contact angle of the solution with teflon surface as a function of surfactant concentration was found to be a reasonably good method to determine the critical micelle concentration. Viscosity and cloud points were also determined. All these quantities are discussed.

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Physicochemical properties of mixed surfacant systems: sodium dodecyl benzene sulfonate with triton X 100

Saiyad

Bhat

Colloid & Polymer Science

1998

“…The values the macromolecules in the solution. 32 The values of the shape factors obtained are given in Table are listed in Table VII. The shape factor n was calculated from the equation VII.…”

Section: 28mentioning

confidence: 99%

Terpolymerization of acrylamide, acrylic acid, and acrylonitrile: Synthesis and properties

Mathakiya

Vangani

1998

J. Appl. Polym. Sci.

Free-radical solution terpolymerization of acrylamide, acrylic acid, and acrylonitrile was carried out in a mixture of dimethylformamide and water (60 : 40, v/v) at 85ЊC using benzoyl peroxide as the initiator. The polymers were characterized by elemental analysis, IR, 1 H-NMR, TGA, and viscosity measurements. Elemental analysis data were used to evaluate the terpolymer composition. The reactivity ratios were determined by Fineman-Ross and Kelen-Tudos methods. The reactivity ratios (r) for the copolymerization of (1) acrylic acid / acrylonitrile with (2) acrylamide was found to be r 1 Å 0.86 { 0.09 and r 2 Å 1.93 { 0.03, respectively, by the Kelen-Tudos method. The Fineman-Ross method yielded a value of r 1 Å 0.86 { 0.05 and r 2 Å 1.94 { 0.09, respectively. The activation energy values for various stages of decomposition were calculated from TGA analysis. Voluminosity (V E ) and the shape factor (n) were also computed from the viscosity measurements in different ratios of the solvent mixture.

“…Some researchers (19,20) have taken η to be equal to (η r -1)/C without the condition of limiting concentration. η has been defined as the shape factor and is expected to have a value between 2.5 and 4 cm 3 g −1 for globular particles; it becomes very large for elongated particles (21). In this article we calculated η without taking the zero concentration limit as we did earlier (14).…”

Section: Methodsmentioning

confidence: 99%

α‐Sulfonato palmitic acid methyl ester‐hexaoxyethylene monododecyl ether mixed surfactant system: Interfacial, thermodynamic, and performance property study

Patil

Mukaiyama

2004

J Surfact & Detergents

Interfacial, thermodynamic, and performance properties of aqueous binary mixtures of α-sulfonato palmitic acid methyl ester, C 14 H 29 CH(SO 3 Na)COOCH 3 (PES), and hexaoxyethylene monododecyl ether, CH 3 (CH 2 ) 11 (OCH 2 CH 2 ) 6 OH (C 12 E 6 ), were investigated with tensiometric, conductometric, fluorimetric, and viscometric techniques. The critical micelle concentration (CMC), maximum surface excess, minimum area per molecule of surfactant at the air/water interface, and the thermodynamics of micellization and adsorption were determined. The CMC was very low for mixed systems, indicating probable use as a detergent with less effect on the environment because of surfactant biodegradability and less amount in the environment. The interaction parameter β m , computed by using the theory of Rubingh and Maeda, indicated an attractive interaction (synergism) between the surfactant molecules, which was also confirmed by proton nuclear magnetic resonance studies in the mixed micelle. The micellar aggregation number (N agg ), determined by using a steady-state fluorescence quenching method at a total surfactant concentration of about ~10 mM at 25°C, was almost independent of the surfactant mixture composition. The micropolarity and the binding constant (K sv ) for the C 12 E 6 /PES mixed system were determined by the ratio of the intensities (I 1 /I 3 ) of the pyrene fluorescence emission spectrum, and the local microenvironment inside the micelle was found to be polar. The viscosity of the mixed system at all mole fractions suggested that mixed micelles are nonspherical in nature. The cloud point of oxyethylene group-containing surfactants was increased by the addition of PES. Foaming was temperature dependent, and a 1:1 mixed system showed minimum foaming. All performance properties were composition dependent.Paper no. S1349 in JSD 7, 87-96 (January 2004).KEY WORDS: Foaming, interaction parameter, micellization, mixed surfactant, viscosity.The association of surfactant molecules into finite-sized molecular aggregates such as micelles in aqueous solution is significant for their use in solubilization, catalysis, dispersion, and technological, biochemical, and pharmaceutical formulations (1,2). Mixed surfactants exhibit performance superior to that of single surfactants, and composition as well as concentration can be optimized for a particular application (3). Synergistic interactions between surfactant molecules in mixed surfactant systems may be exploited to reduce the total amount of surfactant used in a particular application, which ultimately can lead to a reduction in cost and environmental impact (4). Because of their distinctive behavior compared to single surfactants, mixed surfactant systems, such as nonionic-nonionic (5,6), nonionic-anionic (7,8), nonionic-cationic (9), and anioniczwitterionic (10) combinations, have attracted attention in both theoretical studies and practical applications (11). Determination of various physicochemical properties of surfactant mixtures can provide a means to optimize the...