Practical considerations for the injection and separation of nitroaromatic explosives in seawater sample matrices are discussed. The use of high surfactant concentrations and long electrokinetic injections allows for improved detection limits. Sensitivity was enhanced by two mechanisms, improved stacking at the detector-side of the sample plug and desorption of analyte from the capillary wall b...

The photoresponsive interaction of light-sensitive azobenzene surfactants with bovine serum albumin (BSA) at neutral pH has been investigated as a means to control protein folding with light irradiation. The cationic azobenzene surfactant undergoes a reversible photoisomerization upon exposure to the appropriate wavelength of light, with the visible-light (trans) form of the surfactant being mo...

The size and shape of a surfactant aggregate could be altered by using supersaturation like in crystal growth, rather than applying common laws that drive surfactant aggregate formation.

In this investigation, curcumin niosomal nanoparticles were prepared via a simple, efficient and eco-friendly route, thin film hydration (TFH), in the presence of different mixture of the surfactants (tween 60 and span 60). Cholesterol ratio to surfactant, as effective factor, was altered to obtain the optimal nanoparticles. The size, zeta potential, size distribution, entrapment efficiency of ...

Acid phosphatase activity in tape-strip biopsies of human stratum corneum was determined using p-nitrophenyl phosphate as substrate following skin treatment of healthy volunteers with different surfactants at various concentrations. As a short-term effect, enhanced reduction of acid phosphatase activity with stronger surfactants and higher surfactant concentrations was detected. When the skin o...

The esterification activity of microbial lipase (triacyl glycerol hydrolase, E.C. 3.1.1.3) in water-organic biphasic solvent system has been investigated. The lipase produced from Rhizopus arrhizus NCM997 strain by solid-state fermentation, using rice bran as substrate, exhibited novel capability of catalyzing esterification reaction. The partially purified lipase was coated with nonionic surfa...

The effect of different concentrations of the anionic surfactant sodium dodecyl sulfate (SDS) on biodegradation of diesel oil was assessed during 32 days at 10 degrees C, under simulated environmental conditions, in liquid culture and in an alpine soil. Low SDS concentrations (50-100 mg l-1) significantly enhanced oil biodegradation by a psychrotrophic inoculum in liquid culture, whereas higher...

L-Proline and their derivatives are among the most important class of organic catalysts. Three prolinamide surfactants were designed and synthesized. Although the surfactants carried identical catalytic groups, their headgroups contained different functionalities that affected their ability to self-assemble under reverse micelle conditions and hydrogen-bond with the reactants. The surfactant wi...

The successful formulation of particulate dispersions is often hindered by the presence of charged species dissolved in solution. If present at high enough concentrations, these species can reduce the screening length between particles to near zero, allowing rapid coagulation and destabilization. The addition of a mixture of ionic and nonionic surfactants has been shown in a previous publicatio...