• Journal of the Korean Applied Science and Technology
• /
• v.9 no.1
• /
• pp.63-71
• /
• 1992

Four novel amphoteric surfactants of N-alkoxyethylcarboxybetaine series were synthesized via Schotten-Baurnman reaction between four alkyl chlorides contaning 10, 12, 14 and 16 carbon atoms in their N-alkyl group and dimethylaminoethanol to give the intermediate products, alkoxyethyldimethylamine, Quaternization of these intermediates was permitted to form 2-(alkoxyethyldimethylarnmonio) acetates, whose structures were identified by elemental analysis. IR spectrophotometry and $^1$Hnmr spectrometry. The yield of the final products was shown in the range of $74{\sim}77%$ based on the yield of the intermediate products, Surface tension of the aqueous solution of the final products was measured. and the critical micelle concentrations(cmc) were shown in the range of $2.82{\times}10^{-3}{\sim}2.67{\times}10^{-6}$mol/l, and the surface thension at erne was 35${\sim}$43dyne/cm. Cmc was lowered gradually by the increase of carbon numbers in N-alkyl ether containing group. The isoelectric point was shown in the range of 4.08${\sim}$6.03. It showed a tendency to lean toward the acidic site and its range was broadened as increase of the hydrophobic group length. A linear relationship between log erne and the number of carbon atoms(N) in the hydrophobic alkyl chain was shown in the relative equation of log cmc=2.49-0.50N.

• Bulletin of the Korean Chemical Society
• /
• v.30 no.3
• /
• pp.613-617
• /
• 2009

3D-QSARs for the inhibition activities against protox by herbicidal 2-N-phenylisoindolin-1-one derivatives were studied quantitatively using CoMFA and CoMSIA methods. The result of the statistical quality of optimized CoMSIA model 2 ($FF:\;{r^2}_{cv.};\;0.973\;&\;{r^2}_{ncv.};\;0.612$) was higher than that of CoMFA model 1 ($AF:\;{r^2}_{cv.};\;0.414\;&\;{r^2}_{ncv.};\;0.909$). Also, the relative contribution of the optimized CoMSIA model 2 showed the steric (24.6%), electrostatic (31.0%), hydrophobic (ClogP, 23.4%) and H-bond acceptor field (21.0%), respectively. From the results of the contour maps, the protox inhibition activities are expected to increase when steric favor and H-bond acceptor favor groups are substituted on $R_2$ position and positive favor group are substituted on $C_2,\;C_3,\;and\;C_5$ atom in phenyl ring of $R_2$ position. And the inhibition activities are expected to increase when hydrophobic favor group is substituted on $C_1,\;C_3$ atom in phenyl ring of $R_2$ position and $C_1$ atom of $R_2$ position and hydrophilic favor groups are substituted on $C_4$ atom in phenyl ring of $R_1$ position and the terminal group of $R_1$ position.

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

• Membrane Journal
• /
• v.26 no.3
• /
• pp.197-204
• /
• 2016

The objective of this work was to investigate the performance of pervaporation process for recovery of ester compounds from model aqueous solutions and how the fluxes of esters and water were affected by changes in feed concentration and temperature. The flux of ethyl acetate (EA), propyl acetate (PA), ethyl propionate (EP), butyl acetate (BA), and ethyl butyrate (EB) increased with an increase in feed concentration from 0.15 wt% to 0.60 wt%, and increased with temperature change from $30^{\circ}C$ to $50^{\circ}C$. The flux of esters (EA, PA, EP, BA, and EB) was in order of (EA) < (PA, EP) < (BA, EB). This result meant that the flux strongly depended on affinity between esters and membrane surface; EA is the least hydrophobic because it has one hydrophobic function group ($-CH_2-$), (PA, EP) have two ($-CH_2-$), and (BA, EB) are the most hydrophobic because these have three ($-CH_2-$). As well as such an influence of hydrophobicity of ester molecules on ester flux, the influence of hydrophobicity of membrane surface on ester flux needs further investigation. With increase in temperature, water flux of aqueous EA, PA, EP, BA, and EB solution increased. However, water flux of aqueous ester solutions did not change appreciably with increase in concentration. This experimental results may be used as fundamental data for pervaporation (PV) to improve the aroma recovery process as an alternative to thermal evaporation and distillation processes.

• Journal of Korean Society of Environmental Engineers
• /
• v.27 no.12
• /
• pp.1321-1326
• /
• 2005

As a results of this research, the Nakdong River consisted of 43% of hydrophobic fraction, 39% of hydrophilic fraction, and 18% of transphilic fraction. The hydrophobic fraction in this raw water was mostly fulvic acid. Fulvic acid comprised of 62% and the rest was humic acid(38%). There was more carboxylic acid functional roup(64%) than phenolic group(36%). HPI-N and HPI-C comprised of 17% and 22% in the hydrophilic portion, respectively. The results of the membrane fouling test using UF membrane according to NOM fractions. HPI-N caused more fouling than HPI-C. Humic acid caused more fouling than fulvic acid probably due to higher adsorption capacity. Since humic acid has higher adsorption capacity than fulvic acid, it would be more adsorbed onto the membrane pores. The carboxylic acid functional group caused more fouling than the phenolic group.

• Archives of Plastic Surgery
• /
• v.38 no.4
• /
• pp.359-368
• /
• 2011

Purpose: Aquacel Ag$^{(R)}$ is a hydrofiber wound dressing integrated with ionic silver. Sorbact$^{(R)}$ is a hydrophobiccoated dressing that uses the hydrophobic interaction with microbes. In this study, we compared the wound healing effects and the antibacterial effects of Medifoam$^{(R)}$, Betadine soaked, Aquacel Ag$^{(R)}$ and Sorbact$^{(R)}$ dressings against MRSA-infected wounds. Methods: Eighty rats were divided into four groups: Medifoam$^{(R)}$; Betadine soaked; Aquacel Ag$^{(R)}$; and Sorbact$^{(R)}$. A $1.5{\times}1.5cm$ square full-thickness wound was made on the dorsum of each rat and infected with MRSA. Twenty-four hours thereafter, each dressing was applied to the wound and changed every other day. One, 3, 7, 11 and 15 days after the wound infection, swab culture grade, wound bed appearance score, and wound defect size change were evaluated, and 7 and 15 days after, histologic evaluation was compared between the groups. Results: The bacteria load of wounds in the Sorbact$^{(R)}$ group decreased earlier than in the other groups. The wound bed appearance score of the Sorbact$^{(R)}$ group also increased quicker, compared with the other groups. However, the size of wounds of the Aquacel Ag$^{(R)}$ group decreased more rapidly, compared with other groups. From the histologic point of view, there was no significant difference between Betadine soaked, Aquacel Ag$^{(R)}$ and Sorbact groups. Conclusion: The hydrophobic dressing using Sorbact$^{(R)}$ showed a more rapid reduction in the MRSA load and an elevation in the wound bed appearance score, but a slower decrease in wound size change due to detachment of wound bed tissue when the dressing was eliminated in the low exudate wound. The silver-containing hydrofiber dressing using Aquacel Ag$^{(R)}$ was more effective in ultimate wound size reduction, but some debris was trapped in the wound tissue and induced foreign body reaction in the high exudate wound. Thus, ongoing selection process of treatment based on the evaluation of the infectious wound state will be very important.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.42 no.1
• /
• pp.64-73
• /
• 2010

This study was conducted to modify the surface properties of papers by formation of hydrophobic self-assembled monolayer(SAM) on paper surface with silanes. A base paper I(0.5% AKD) and base paper II(1.0-1.5% AKD) were reacted with silanes(PFDTES, DMDCS, MODDCS) by immersion method and vapor deposition method. Hydrophobic SAMs(contact angle value>$120^{\circ}C$) were obtained on all papers after treatment with $10^{\mu}l$ PFDTES for 15min, with $50^{\mu}l$ DMDCS for 30min, with $50^{\mu}l$ MODDCS for 300min. When applying PFDTES to paper surface, lower silane concentration and shorter reaction time were required, whereas MODDCS with long alkyl chain required the longest reaction time of 300min. The st$\ddot{o}$ckight sizing degree of silane treated papers were increased between 105sec(base paper I) and 130sec(base paper II). The wet tensile strength of PFDTES-treated base papers(I, II) increased by 10-34% after SAM formation. However, the wet tensile strength of the DMDCS-treated base paper(I) was found to decrease from 0.067kN/m to 0.038kN/m; this may due to the cellulose degrading as a result of generated hydrogen chloride when hydroxyl group of cellulose were reacted with DMDCS. No apparent changes of PPS roughness on silane-treated papers are observed. The ATR-IR spectrum showed absorption peak located at 465 and 1200cm-1 which can be assigned to the Si-O-C asymmetric stretching and Si-O-C bonds, respectively.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
• /
• v.15 no.1
• /
• pp.27-34
• /
• 2017

In this study, desorption characteristics of Cs from clay according to the hydrophobic alkyl chain length of the cationic surfactant were investigated. Alkyltrimethylammonium bromide was used as a cationic surfactant, and the length of the hydrophobic alkyl chain of the cationic surfactant was varied from -octyl to -cetyl. The adsorbed amount of the cationic surfactant on montmorillonite increased with the length of the hydrophobic alkyl chain, and intercalation of the cationic surfactant into the clay interlayer increased the interlayer distances. The Cs removal efficiency was also enhanced with increasing alkyl chain length, and the cationic surfactant with the cetyl group showed a maximum Cs removal efficiency of $992{\pm}2.9%$.

• Asian Journal of Atmospheric Environment
• /
• v.6 no.1
• /
• pp.67-72
• /
• 2012

The chemical characterization of water-soluble organic carbon in ash emitted from a coal combustion boiler has not been reported yet. A total of 5 ash samples were collected from the outlet of an electrostatic precipitator in a commercial 500 MW coal-fired power plant, with their chemical characteristics investigated. XAD7HP resin was used to quantify the hydrophilic and hydrophobic water-soluble organic carbons (WSOC), which are the fractions of WSOC that penetrate and remain on the resin column, respectively. Calibration results indicate that the hydrophilic fraction includes aliphatic dicarboxylic acids and carbonyls (<4 carbons), amines and saccharides, while the hydrophobic fraction includes aliphatic dicarboxylic acids (>4-5 carbons), phenols, aromatic acids, cyclic acid and humic acid. The average mass of the WSOC in the ash samples was found to depend on the bituminous coal type being burned, and ranged from 163 to 259 ${\mu}g$ C/g of ash, which corresponds to 59-96 mg C of WSOC/kg of coal combusted. The WSOC mass accounted for 0.02-0.03 wt% of the used ash sample mass. Based on the flow rate of flue gas produced from the combustion of the blended coals in the 500 MW coal combustion boiler, it was estimated that the WSOC particles were emitted to the atmosphere at flow rates of 4.6-7.2 g C/hr. The results also indicated that the hydrophilic WSOC fraction in the coal burned accounted for 64-82% of the total WSOC, which was 2-4 times greater than the mass of the hydrophobic WSOC fraction.

• Journal of the Korean Applied Science and Technology
• /
• v.32 no.3
• /
• pp.546-567
• /
• 2015

Silicone-based surfactants consist of a hydrophobic organosilicone group coupled to one or more hydrophilic polar groups, while the hydrophobic groups of hydrocarbon surfactants are hydrocarbons. Silicone surfactants have been widely used in many industrial fields starting from polyurethane foam to construction materials, cosmetics, paints & inks, agrochemicals, etc., because of their low surface tension, lubricity, spreading, water repellency and thermal and chemical stability. A wide range of silicone surfactant structures are required to provide the functional diversity for reflecting the necessities in the various applications. This review covers the basic properties and the synthetic schemes of polydimethylsiloxane and reactive polysiloxanes as hydrophobic siloxane backbones, the main reaction schemes, such as hydrosilylation reaction, for coupling reactive polysiloxanes to hydrophilic groups, and the synthetic schemes of the main polysiloxane surfactants including polyether-, ionic-, carbohydrate-type surfactants.