• Journal of the Korean Applied Science and Technology
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• v.15 no.3
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• pp.55-60
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• 1998

The sodium ${\alpha}-sulfo$ fatty acid vinyl ester oligomers, which are oligomer type surfactants were prepared by polymerization with fatty acid vinyl acetate. The ${\alpha}-sulfonation$ of fatty acid vinyl ester oligomers were carried by direct addition of sulfur trioxide. The dispersing performance of oligomer type anionic surfactants and sodium dodecyl sulfate(SDS) in the aqueous suspension of iron oxide and titanium dioxide particles was evaluated by particle size distribution and zeta-potential measurement. As results, the particles of iron oxide and titanium dioxide were flocculated by addition of small amount of oligomer type anionic surfactants and sodium dodecyl sulfate(SDS), then the flocks redispersed by more addition of oligomer type anionic surfactants and SDS. The flocculation, redispersion process was observed in lower concentration range of oligomer type anionic surfactants than SDS. Especially, the dispersing action of sodium ${\alpha}-sulfo$ palmitic acid vinyl ester oligomer was better than sodium ${\alpha}-sulfo$ lauric acid vinyl ester oligomer.

• Membrane Journal
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• v.4 no.2
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• pp.106-112
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• 1994

The ultrafiltration(UF) and reverse osmosis(RO) tests for a model metal plating wastewater prepared with zinc sulfate, showed the zinc ion rejection coefficient of over 99% and the permeate flux of $1.49 {\times} 10^{-3}cm/sec$ at pH = 8.3. The effect of cyanide on the zinc removal was investigated. When the amount of cyanide addition was same the zinc content, the zinc was removed over 99% and the cyanide was excluded about 93%. The addition of the surfactants such a LAS-Na and EDTA-Na was found to reduce the permeate flux down to $0.76 {\times} 10^{-3}cm/sec$ at the RO membrane.

• Korean Chemical Engineering Research
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• v.47 no.2
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• pp.190-194
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• 2009

In this study sodium dodecyl sulfate (SDS), which was anionic surfactant, was added for forming micelles to remove iron ion that could be contained with small amount in industrial water. Then aggregates binding between iron ions and micelles were rejected by a ceramic microfiltration membrane. As result of SDS concentration effect on removal rates of iron and SDS in modified iron solution, the removal rate of iron was the highest value of 92.26% and the removal rate of SDS was 61.10% a little higher than the result of calcium ion at 8 mM which was CMC (Critical micelle concentration) of SDS. As final resistance of membrane fouling $R_f$ increased the more at the higher SDS concentration, it showed the highest value at 4 mM and the lowest at 10 mM of SDS. The final permeate flux $J_{180}$ had the highest value and the largest total permeate volume could be finally acquired at SDS 10 mM. In case of CMC 8 mM, low $R_f$ was shown as same as that of 10 mM until 80 minutes of operation, and tended to increase dramatically to 120 minutes and increase slowly again until 180 minutes.

• Journal of the Korean Applied Science and Technology
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• v.34 no.1
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• pp.116-124
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• 2017

A plate-type inorganic pigment complex was manufactured in a manner that treats the surface of the complex by adjusting zeta potential between talc, an inorganic pigment used as a material for color cosmetics, and hydrophobic silica. Talc, which is usually used in the prescription of color cosmetics, is a plate-type, white-colored inorganic substance with good application and spreadability to skin. Furthermore, it features excellent dispersibility and extensibility as well as outstanding heat tolerance, light stability, and chemical resistance. In general, silica contributes to durable makeup and stabilized formulation. This paper covers a process of manufacturing an inorganic pigment complex, where hydrophobic silica was applied to the surface of talc by using differences in zeta potential after the surface charges of talc and hydrophobic silica had been adjusted with cationic and anionic surfactants, respectively. The resulting inorganic pigment complex was composed of talc whose surface is coated hydrophobic silica to the thickness of $1{\mu}m$ or less, which developed an effective hydrophobic property. Zeta potential was measured to analyze the surface charge of an inorganic pigment, and FT-IR, used to check the functional group of a surfactant, was applied to treat the surface of the pigment. The surface of the inorganic pigment complex was observed employing SEM, EDS, and FIB, while its structure was confirmed with XRD and FT-IR.

• Applied Chemistry for Engineering
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• v.8 no.5
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• pp.830-836
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• 1997

The surface modification of iron oxide particle produced from steel-pickled acid by sodium-contained materials was studied. The molar ratio of $SiO_2$ to $Na_2O$ of sodium silicate was 1, 2, 3.5, respectively. The dispersion stability of iron oxide suspension as functions of amount of silica and pH was evaluated by surface charge and sedimentation velocity of iron oxide particle. Then the amount of sodium silicate was determined to provide a dispersion stability of iron oxide particle above pH 7. Finally, the surface modification of iron oxide particle with sodium silicate as silica-contained materials was done by wet ball milling. In the results of study, the dispersion stability of silica modified iron oxide particle was largely depended on amount of silica and pH together. The untreated iron oxide was unstable at pH 8, i.e. isoelectric point, but, the surface modified iron oxide particle with 0.8wt% silica was stable above pH 5. The dispersion stability was enhanced with 0.2wt% of anionic polyelectrolyte.

• Applied Chemistry for Engineering
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• v.10 no.7
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• pp.974-978
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• 1999

This study was concerned with the scouring effect of anionic surfactants, PAPE(sodium polyoxyethylene alkyl phosphoric ester) for cotton fibres. Sodium polyoxyethylene(7) nonylphenyl phosphoric ester(CPB-1) and the sodium polyoxyethylene(7) tridecyl phosphoric ester(CPB-2) were synthesized by the phosphoric esterification reaction from NP-7(polyoxyethylene(7) nonylphenyl ether) and TDA-7(polyoxyethylene(7) tridecyl ether) as scouring agents. Defoaming ability, fibre wetting time and absorbency rate of scouring agents were investigated. Being compared with the conventional scouring agent(Ultravon GP; Ciba-guyge Co.), CPB-1 and CPB-2 showed a higher defoaming ability in the cotton scouring process at room temperature. And CPB-1 has a higher wetting effect than the agents, CPB-2 or GP in distilled water bath but CPB-2 showed more scouring effect in 1.2 wt % NaOH solution bath.

• Membrane Journal
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• v.18 no.1
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• pp.7-25
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• 2008

Sodium dodecyl sulfate, which was anionic surfactant, at a concentration higher than its critical micellar concentration was added to calcium solution for forming micelles. Then aggregates were formed by adsorption or binding of calcium ions on the surface of micelles, and gathering between them, and then rejected by two kinds of ceramic membranes to remove calcium ions. As result, rejection rates of calcium were higher than 99.98%. And in our experimental range the higher TMP trended to increase the resistance of membrane fouling ($R_f$), total permeate volume ($V_T$), dimensionless permeate flux ($J/J_o$) and permeate flux (J) because TMP was driving force. And we investigated effects of $N_2$-back-flushing time and filtration time, that was back-flushing period, during periodic $N_2$-back-flushing on ceramic membranes. As result, optimal BTs for NCMT-623l ($0.07{\mu}m$ pore size) and NCMT-7231 membrane ($0.10{\mu}m$) were 10 sec and 15 sec, respectively. Also, optimal FT was 5 min for both membranes, and the frequent $N_2$-back-flushing could decrease membrane fouling effectively. Then, the optimal conditions resulting from our experiments for synthetic calcium solution were applied to groundwater using as washing process of soymilk package. As result, rejection rates of calcium were higher than 99.98%.

• Journal of the Korea institute for structural maintenance and inspection
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• v.15 no.1
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• pp.263-270
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• 2011

In this study, the performance of Poly-Naphthalene Sulfonate (PNS) type-admixture used widely in South Korea and Polycarboxilic type-admixture(i.e., WF2000) developed in the J company of the domestic, for precast concrete products produced in the factories, was evaluated. With the 20% reduced usage of WF2000 compared to PNS type-admixture, workability was considerably improved due to high water-reducing ratio, accelerating effect of concrete setting and accelerant dispersant action, which the product has, under the high temperature. In addition, the development of initial and long-term strengths of PHC plies was predominant. For WF2000, it is also possible to correspond with the change of original materials and environmental conditions since the control of water-reducing and supporting forces is feasible. Accordingly, it was noted that WF2000 is superior for deterioration of production & workability and bad casting problems in summer and the solution of initial strength reduction problem due to the delay of setting in winter.

• Journal of the Korean Chemical Society
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• v.34 no.6
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• pp.629-636
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• 1990

Dephosphorylation of p-nitrophenyldiphenylphosphate(p-NPDPP) mediated by anions of sodium 2-alkylbenzimidazole-5-sulfonate(R-BI-SO$_3$Na) in CTABr micellar solutions are obviously slower than that by anion of sodium benzimidazole-5-sulfonate(BI-SO$_3$Na), and the reation rates were decreased with increase of lengths of alkyl groups. This presents a striking contrast to the reactions in aqueous solutions without added CTABr, of which the reaction rates are on approximately same levels. It seems due to steric effect of alkyl groups of R-BI$^-$SO$_3$Na in the Stern layer of micelle, and it is supported by measured activation parameters(△H$^\neq$/TEX>, △G$^\neq$/TEX> and △S$^\neq$/TEX>) of the reactions in aqueous and micellar solutions. In addition to nucleophilic ability of benzimidazole moiety of R-BI$^-$SO$_3$Na on the reactions, these compounds with long alkyl groups(nonyl to pentadecyl) are micellized for themseleves, and increase the reaction rates due to their micellar catalyses in aqueous solutions, not including CTABr.

• Applied Chemistry for Engineering
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• v.7 no.2
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• pp.289-298
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• 1996

Eight kinds of poly(oxyethylene, oxyisopropylene) dodecyl ethers were synthesized by adding ethylene oxide and isopropylene oxide with each 5 and 10 moles alternatively on dodecanol. The addition of EO and PO for eight kinds of sodium poly(oxyethylene, oxyisopropylene) dodecyl ether sulfates was identified with HPLC, $^1H$ NMR, hydroxy value, and IR spectrum. In order to verify the sulfation the number of EO and PO molecules was obtained by spectra and Epton method. The yields of products sulfated by chlorosulfonic acid were 90~96%.