Chemical-flooding schemes for recovering residual oil have been in general less than satisfactory due to loss of chemicals by adsorption on reservoir rocks, precipitation, and resultant changes in rock wettability. Adsorption and wettability changes are determined mainly by the chemical structure and mix of the surfactants, surface properties of the rock, composition of the oil and reservoir fl...

conclusions the most effective enhancer for aha and ha were liquid paraffin and glycerol, respectively. the most effective surfactant for both aha and ha was tween 80. the effects of the enhancers were increased by prolonging the exposure time. results after 1.5 and 12 hours, the maximum permeated amount of aha were 89.8 and 342.5 mg, respectively, which related to the formulations with liquid ...

Silicone surfactants are becoming increasingly important in the pharmaceutical and cosmetic industry, because of their versatility, low cost, and technological advantages. The present study was designed to measure the critical micellar concentration of three non-ionic silicone surfactants, one water-soluble and two lipid-soluble. We measured surface tension with a technique based on drop geomet...

There are new chemical substances that increase the strength of washing products such as surfactants. However, these products are not biodegradable and can all be found in surface water, groundwater. Cationic surfactants are one of the pollutants of greatest danger to man is his environment. Therefore, we have determined some parameters of three cationic surfactants by molecular modeling, using...

Surfactants are among the most versatile and widely used excipients in pharmaceuticals. This versatility, together with their pH-responsive membrane-disruptive activity and low toxicity, could also enable their potential application in drug delivery systems. Five anionic lysine-based surfactants which differ in the nature of their counterion were studied. Their capacity to disrupt the cell memb...

This laboratory study examined viability and infectivity of the entomopathogenic nematode (EPN) Heterorhabditis bacteriophora Poinar in solutions containing four different turfgrass soil surfactants: Revolution (Aquatrols Corp., Paulsboro, NJ), Aqueduct (Aquatrols Corp., Paulsboro, NJ), Cascade Plus (Precision Laboratories Inc., Waukegan, IL) and OARS (Aqua-Aid Inc., Rocky Mount, NC). Infective...

The interaction forces provided by silicone polyether (SPE) surfactants, adsorbed at the interface of octadecyltrichlorosilan monolayer and aqueous surfactant solution, were measured by atomic force microscopy. Changes in the forces in the presence of ethanol were examined for a series of comb-type SPE surfactants. It was found that the steric repulsion provided by the SPE molecules persisted u...

Membrane proteins play vital roles in every aspect of cellular activities. To study diverse membrane proteins, it is crucial to select the right surfactants to stabilize them for analysis. Despite much effort, little progress has been made in elucidating their structure and function, largely because of a lack of suitable surfactants. Here we report the stabilization of a G protein-coupled recep...

Surface tensiometry and small-angle neutron scattering have been used to characterize a new class of low-surface energy surfactants (LSESs), "hedgehog" surfactants. These surfactants are based on highly branched hydrocarbon (HC) chains as replacements for environmentally hazardous fluorocarbon surfactants and polymers. Tensiometric analyses indicate that a subtle structural modification in the ...

This paper describes our experimental testing of linear viscoelastic creep behaviours in HamiMelon. Experimental data shows that HamiMelon has complex viscoelastic property which cannot be well described by the standard model. Consequently, this study develops a fractional derivative model to describe such complex viscoelastic creep behaviours of Hami Melon. The analytical creep function of the...