experimental-measurement-settling-velocity-spherical-particles

Experimental Measurement of Settling Velocity of Spherical Particles in Unconfined and Confined Surfactant-based Shear Thinning Viscoelastic Fluids

An experimental study is performed to measure the terminal settling velocities of spherical particles in surfactant based shear thinning viscoelastic ...

The University of Texas at Austin

The fundamental aqueous and surface properties of a family of sulfate gemini surfactants have been characterized. The critical micelle concentrations (cmc) were determined by both electrical conductivity and surface tension methods. The cmc values were found to be two orders of magnitude lower than those measured for single tail surfactants. The cmc values depend primarily on the surfactant tail length, and relatively little on the spacer length and solution temperature. The surface tension measurements suggest that current family of gemini surfactants have higher tendency to spontaneously adsorb at the air-water interface and thus are much more efficient in reducing surface tension than conventional single-chain surfactants. Thermodynamic calculations of Gibbs free energies for micellization and adsorption indicate surface adsorption is promoted more than micellization for these sulfate gemini surfactants. This type of molecules may therefore be very efficient and cost-effective in applications that require ultra-low interfacial tensions and high interfacial activities.

A family of alkyl sulfate gemini surfactants. 1. Characterization of surface properties.

A family of sulfate gemini surfactants that has great potential for various industrial applications was previously prepared and characterized in our lab. The unique and versatile structure of these surfactants has endowed them with properties that are attractive for enhanced oil recovery (EOR). A detailed experimental study was carried out and is presented here on the water-oil interfacial properties of these novel molecules. This series of seven sulfate gemini surfactants of different hydrophobic tail and spacer group lengths shows systematic trends in interfacial tension (IFT) reduction with changing solution conditions. These molecules exhibit extraordinary aqueous stability even in high salinity and hard brines. Ultra-low interfacial tension values were measured with low surfactant concentrations. The results from this study showed the potential of utilizing these surfactants at low concentrations and in harsh reservoir environments.

Article	Year
A family of alkyl sulfate gemini surfactants. 1. Characterization of surface properties. Journal of colloid and interface science\| PubMed ID: 23692916	2013
A family of alkyl sulfate gemini surfactants. 2. Water-oil interfacial tension reduction. Journal of colloid and interface science\| PubMed ID: 23895947	2013

Mukul M. Sharma

Biography

JoVE Journal Publications

Other Publications