• YAKHAK HOEJI
• /
• v.20 no.3
• /
• pp.156-161
• /
• 1976

The salting in and salting out of Octoxynol, N.F., a nonionic polyoxyethylated surfactant by n-alkylamine hydrochlorides ws investigated by measuring their effect on the cloud point of the surfactant at various salt concentrations. The carbon number of the alkyl chain was varied from zero to twelve. Ammonium chloride, methylamine hydrochloride and ethylamine hydrochloride tended to salt out the surfactant, lowering its cloud point in proportion to the salt concentration. n-Ankylamine and n-butylamine hydrochlorides showed salting-out effect at low concentrations of the electrolyte, while their effects were leveled off and showed rather salting-in trend at higher concentrations of the electrolyte. These salting-in effect was ascribed to the formation of a hydrotropy of the n-alky lammonium cations with the surfactant. The higher homolog compounds of n-alkylamine hydrochlorides showed extraordinarily high salting-in effect at very low oncentrations of the electrolyte. These large salting-in effects were more drastic as the chain length was getting longer. These large increases of the cloud point of the surfactant were attributed to the formation of mixed micelles of n-alkylammonium cations with the polyoxyethylated surfactant.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2002.09a
• /
• pp.187-190
• /
• 2002

Reductive dechlorination of endosulfans was studied with zero valent metals (ZVMs) and bimetals in aqueous batch reactors. The effect of surfactants was evaluated. Endosulfan was successfully dechlorinated with zero valent iron. However, a bimetal, palladium coated iron (Pd/Fe) showed a highly enhanced reactivity for both endosulfan I and II indicating palladium act as a dechlorination catalyst on the iron. The effect of surfactants on degradation with ZVM has been very controvertible. Variable concentration of a nonionic surfactant, Triton X-100 and an anionic surfactant, SDS were added into the reactor with ZVM. The reaction rates of endosulfan were increased with both surfactants. In the case of Triton X-100, the reaction rate was increased with the increasing surfactant concentration up to 400 mg/L. Addition of small amount of surfactant under the CMC, the reaction rate was increased. However, the enhancing effect was diminished when a higher concentration of surfactant (1,000 mg/L) was used. Current study implicate that the surfactant adsorbed on the metal surface might increase the surface concentration of endosulfan resulting in the increased reaction rate. However, partitioning of endosulfan into the micelle formed at the high concentration of surfactant diminish the enhancing effect by reducing the contact chance between target compound and the metal surface.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.43 no.5
• /
• pp.49-54
• /
• 2011

Curtain coating has been considered as the best coating technology because it is a coating technology that forms contour coating layer with better coverage. To increase the curtain stability surfactants are being used. In this study, the effect of a surfactant on the stability of curtain coating colors was examined by evaluating dynamic surface tension with a bubble surface tensiometer. Di-2-ethylhexyl sodium sulfosuccinate was used as a surfactant since it showed low dynamic surface tension at low surface age. And we evaluated the influence of surfactant on coating color properties including surface tension, viscosity and curtain stability. The surface tension of coating color was decreased when surfactant addition was increased up to 0.5 pph, but it was leveled off at 0.3 pph of surfactant addition. With the increase of surfactant addition rate, viscosity of coating color were increased. Micelles formed by surfactant contributed to the increase of the viscosity. Curtain stability was improved with the addition of surfactant until it reached up to 0.5 pph. Excessive addition of surfactant (> 0.5 pph) didn't improve curtain stability. This was attributed to Marangoni effect(self-healing) and decreasing of curtain thickness.

• Korea-Australia Rheology Journal
• /
• v.15 no.4
• /
• pp.179-185
• /
• 2003

Associating polymers act as flocculants in colloidal suspensions, because the hydrophobic groups (hydrophobes) can adsorb onto particle surfaces and create intermolecular cross-linking. The steady-shear viscosity and dynamic viscoelasticity were measured for suspensions flocculated by multichain bridging of associating polymers. The effects of surfactant on the suspension rheology are studied in relation to the bridging conformation. The surfactant molecule behaves as a displacer and the polymer chains are forced to desorb from the particle surfaces. The overall effect of surfactant is the reduction of suspension viscosity. However, the additions of a small amount of surfactant to suspensions, in which the degree of bridging is low, cause a viscosity increase, although the number of chains forming one bridge is decreased by the forced desorption of associating polymer. Since the polymer chains desorbed from one bridge can form another bridge between bare particles, the bridging density over the system is increased. Therefore, the surfactant adsorption leads to a viscosity increase. The surfactant influences the viscosity in two opposing ways depending on the degree of bridging.

• Korea-Australia Rheology Journal
• /
• v.17 no.4
• /
• pp.157-164
• /
• 2005

Hydrodynamic characteristic of surfactant drag-reducing flows is still not fully understood. This work investigated the temperature and diameter effect on hydrodynamic characteristic of cationic surfactant drag reducing flows in pipes. Solution of oleyl bishydroxyethyl methyl ammonium chloride (Ethoquad O/12), 900 ppm, as a cationic surfactant and sodium salicylate (NaSal), 540 ppm, as a counter-ion was tested at 12, 25, 40, and $50^{\circ}C$ in pipes with diameter of 13, 25, and 40 mm. Drag reduction effectiveness of this surfactant solution was evaluated in 25 mm pipe from 6 to $75^{\circ}C$. Rheological characteristic of this solution was measured by stress control type rheometer with cone-and-plate geometry. Scale-up laws proposed by previous investigators were used to evaluate the flow characteristic of the solution. It was found that this surfactant solution has clear DR capability until $70^{\circ}C$. Result of this work suggested that temperature has a significant influence in changing the hydrodynamic entrance length of surfactant drag reducing flows. From rheological measurement, it was found that the solution exhibits Shear Induced Structure at all temperatures with different degree of peak viscosity and critical shear rate.

• Preventive Nutrition and Food Science
• /
• v.3 no.2
• /
• pp.143-151
• /
• 1998

Protein -surfactant interactions have been investigate by measuring ζ-potential of $\beta$-lactoglobulin-coated emulsion droplets and $\beta$-lactoglobulin in solution in the rpesenceof surfactant, with particular emphasis on the effect of protein heat treatment(7$0^{\circ}C$, 30min). When ionic surfactant (SDS or DATEM) is added to the protein solution, the ζ-potential of the mixture is found to increase with increasing surfactant concentration, indicating surfactant binding to the protein molecules. For heat-denatured protein,it has been observed that the ζ-potential tends to be lower than that of the native protein. The effect of surfactant on emulsions is rather complicated .With SDS, small amounts of surfactant addition induce a sharp increase in zeta potential arising from the specific interaction of surfactant with protein. With further surfacant addition, there is a gradual reductio in the ζ-potential, presumably caused by the displacement of adsorped protein (and protein-surfactant complex) from the emulsion droplet surfac by the excess of SDS molecules. At even higher surfactant concentrations, the measured zeta potential appears to increase slightly, possibly due to the formation of a surfactant measured zeta potential appears to increase slightly, possibly due to the formation of surfactant micellar structure at the oil droplet surface. This behaviour contrastswith the results of the corresponding systems containing the anionic emulsifier DATEM, in which the ζ-potential of the system is found to increase continuously with R, particularly at very low surfactant concentration. Overall, such behaviour is consisten with a combination of complexation and competitive displacement between surfactant and protein occurring at the oil-water interface. In addition, it has also been found that above the CMC, there is a time-dependent increase in the negative ζ-potential of emulsion droplets in solutions of SDS, possibly due to the solublization of oil droplets into surfactant micelles in the aqueous bulk phase.

• The Korean Journal of Physiology and Pharmacology
• /
• v.1 no.1
• /
• pp.65-70
• /
• 1997

In order to investigate the effect of ANP on surfactant secretion from alveolar type II cell(AT II cell) during circulatory derangement in adult respiratory distress syndrome (ARDS), the secretion of surfactant from AT II cells was evaluated in purely isolated AT II cultures from rat lungs. For the simulation of sympathetic stimulation during circulatory derangement, primary AT II cultures were incubatedwith isoproterenol and IBMX. In this isoproterenol stimulated AT II cells, ANP were added in the media for the investigation of effect of ANP on surfactant secretion from AT II cells. For the evaluation of surfactant secretion, $[^3H]-methylcholine$ was incorporated and the level of radiolabelled choline chloride secreted from the cells was determined. As previously reported, isoproterenol and IBMX stimulated surfactant secretion from AT II cells. Isoproterenol showed synergistic increase of surfactant secretion with IBMX in AT II cells. In isoproterenol stimulated AT II cells, physiological level of ANP inhibited the secretion of surfactant in primary cultures of AT II cells. On the basis of these experimental it is suggested that, in association with ciculatory change during ARDS, increased secretion of ANP by the pulmonary edema, hypoxia and congestive heart heart failure might aggravate the symptoms of ARDS by reduction of surfactant secretion from AT II cells.

• Journal of Life Science
• /
• v.20 no.11
• /
• pp.1611-1616
• /
• 2010

The purpose of this research was to determine the effect of surfactant micelles on lipid oxidation in W/O/W multiple emulsions. The content of ferric irons and hydroperoxide in the continuous phase in W/O/W multiple emulsions was measured as a function of Brij micelle. The concentration of ferric iron and hydroperoxide in the continuous phase increased with increased storage time (1~6 days). Lipid oxidation rates, as determined by the formation of lipid hydroperoxides, TBARs and headspace hexanal, in the W/O/W multiple emulsions containing ferric iron decreased when 3% surfactant micelles were exceeded. These results indicate that excess surfactant micelles could alter the physical location and prooxidant activity of iron in W/O/W multiple emulsions.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2004.04a
• /
• pp.47-51
• /
• 2004

The purpose of this research was to evaluate the effect of mixed surfactant solution for removal of perchloroethylene (PCE) in soil. Ten different surfactant solutions were used in column studies. Mixed surfactant solutions (anionic and nonionic) were most effectively worked in the sandy soil for removal of PCE as a result of synergism between the two types of surfactants. The effectiveness of the mixture of surfactants was 35 % greater than that for the anionic or nonionic surfactant alone. The results indicate that mixed surfactant solution leaching is a promising candidate for the remediation of PCE contaminated sandy soil.

• Applied Chemistry for Engineering
• /
• v.35 no.3
• /
• pp.230-238
• /
• 2024

In the present work, the interaction of lipid-based zwitterionic surfactant CDP-W with the vesicle membrane of phospholipids was investigated. For this purpose, interfacial properties such as critical micelle concentration (CMC) and surface tension were measured for the zwitterionic surfactant CDP-W and lecithin S100-3. The zeta potential of 1 wt% aqueous surfactant solutions was also measured as a function of pH to determine the iso-electric point of CDP-W surfactant, where the characteristic of CDP-W surfactant changes from a cationic surfactant to an anionic surfactant. Based on the iso-electric point measurement of CDP-W surfactant, the effects of pH change and CDP-W addition on the stability of S100-3 liposome systems were studied, such as average particle size, polydispersity index (PDI), and zeta potential. The effect of CDP-W on the fluidity characteristics of liposome membranes such as fluorescence anisotropy ratio, deformability, and melting point was investigated at pH 6 where the most stable liposomes were prepared to understand the effect of the fluidity of the liposome membrane on the encapsulation efficiency of active materials and the stability of liposome systems.