• Journal of the Korean Chemical Society
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• v.55 no.2
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• pp.163-168
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• 2011

The variations of molar conductivity of various surfactants such as sodium caprylate, sodium laurate, sodium palmitate, sodium stearate, sodium oleate, sodium dodecyl sulphate, and lithium dodecyl sulphate with concentrations of the surfactants for each of the solutions consisting of mixtures of varying concentrations of N-methyl acetamide in water at constant temperature of $30{\pm}0.2^{\circ}C$ were studied. The critical micelle concentration (CMC) for each surfactant is measured. It is found that the CMC values in mixtures of N-methyl acetamide and water solutions of various surfactants are lower than the CMC values in water, and the driving force for micelle formation correlates with solvophobicity. The surfactant-solvent interactions that drive amphiphilic self-organization in N-methyl acetamide in water are discussed. Thermodynamic parameters were evaluated for micellar system to explain the results.

• Food Engineering Progress
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• v.14 no.1
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• pp.27-34
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• 2010

Multilayer edible coatings was applied to lemon with beeswax-hydroxypropyl methylcellulose (BW-HPMC), soybean oil-carboxymethyl cellulose (SBO-CMC), and carnaubawax-shellac-locust bean gum (CW-SL-LBG), respectively. The multilayer was composed of two layers of the same material, but the outer layer only contained vitamins C and E as antioxidants. Coating amounts built on lemon peel were measured to be large in the order of CW-SLLBG> BW-HPMC> SBO-CMC. The coated lemons were stored at 30${^{\circ}C}$ for 12 days. CW-SL-LBG showed the least change during the storage in weight loss, rotten rate, firmness, and browning. Whereas SBO-CMC had the least change in pH, soluble solid amount, and titratable acidity. In a sensory test, CW-SL-LBG was evaluated to be the best in the attributes such as spoilage, glossiness, color, firmness, and flavor. Overall CW-SL-LBG was judged to be the best for multilayerd coating with vitamin C and E on lemon.

• Journal of the Korean Applied Science and Technology
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• v.29 no.1
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• pp.47-53
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• 2012

This study is concerned with coemulsifier which is better emulsifiable properties than emulsifier itselves' use only. It's compound was synthesized by esterification of propylene glycol and succinic acid. The structure of them was comfirmed with FT-IR and $^1H$-NMR. Surface active properties with surface tension, cmc, emulsing power were tested respectively at given conditions. Their surface tensions in the aqueous solution was decreased to 33-35 dyne/cm and their cmc was evaluated by surface tension method. And it's emulsifying power was excellent in jojoba oil. As results, the synthesized dipropylene glycol succinate is expected to apply as O/W coemulsifier.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.19 no.4
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• pp.303-311
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• 1986

This work was designed as basic studies on the development of diet for the treatment of obesity. The effect of alginic acid which is the major component of brown algae was investigated by comparing with agar, cellulose, carboxymethylcellulose (CMC), chitin, and lignin as dietary fibers. These dietary fibers ($10\%$) supplemented to basic diet were fed ad libitum to Sprague Dawley rat for 4 weeks, and the inhibitory effects on obesity were evaluated by measuring body weight gain and feed efficiency, the content of glucose and cholesterol in serum, lipase activity in serum, lipid content in liver, adipose tissue around epididymis and ovarium, and Lee index etc. Among the inhibitory effect of these dietary fibers on obesity, lignin was the most effective (p<0.001), followed by Na-alginate (p<0.01) for body weight gain, but lignin was the most effective, followed by CMC, and followed by Na-alginate for feed efficiency (p<0.001). In the inhibitory effects on lipid accumulation in liver and adipose tissue around epididymis and ovarium, lignin and Na-alginate group among these dietary fibers were more effective than others, but there was no significant difference between male and female. The inhibitory effect on obesity evaluated by Lee index was effective in the order of Na-alginate>lignin>CMC>chitin>cellulose (p<0.001). The decreasing effects of lipid content in liver by dietary fibers were found in the order of agar>CMC>cellulose>Na-alginate>chitin>lignin (p<0.001). Glucose content in serum was significantly decreased in cases of CMC, lignin and Na-alginate, whereas a slight difference was found in chitin, but cholesterol content in serum was decreased for all dietary fibers examined except cellulose group. The increasing effect of lipase activity in plasma was found in cases of Na-alginate and chitin, while cellulose, CMC and lignin groups were decreased.

• Membrane Journal
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• v.15 no.3
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• pp.213-223
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• 2005

We prepared an anti-adhesion membrane made of sodium hyaluronate/sodium carboxymethylcellulose (HA/CMC) and evaluated its effectiveness for adhesion prevention in a rat model. The anti-adhesion membrane was prepared by lyophilizing HA/CMC solution and cross-linking properly with 1-Ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDAC). In a cecum/abdominal wall abrasion model of Sprague-Dawley rat, cecal serosa and abdominal wall were abraded in $1\times2\;(cm^2)$ with a bone burr after peritoneal midline incision and sutured at 3 points around the injured surface. The denuded cecum was covered with HA/CMC membrane (experimental group), or nothing (control group) and apposed to the abdominal wall. Most of the control group represented 3 or more of adhesion grade at POD 7, 14, 21, and 28, whereas $60\~70\%$ of the experimental group was 2 or less of adhesion grade at 14, 21, and 28. It was similar in the adhesion strength. In a general manner, the adhesion grade and strength showed gradual increasing until POD 14, almost same or a little increasing POD 21, but decreasing POD 28. Also the control group was much higher in adhesion grade, strength, and area than the experimental group. It is expected that the anti-adhesion membrane will have a good clinical result in postoperative adhesion prevention.

• Journal of the Korean Electrochemical Society
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• v.22 no.4
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• pp.155-163
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• 2019

Mixture electrodes of a graphite having a good cycle performance and a silicon monoxide (SiO) having a high capacity are fabricated and their cycle performances are evaluated as negative electrodes for lithium-ion batteries. The electrode prepared by mixing the natural graphite and carbon-coated SiO in a mass ratio of 9:1 shows a reversible capacity of $480mAh\;g^{-1}$, 33% higher than that of graphite. However, the capacity deteriorates continuously upon cycling due to the volume change of silicon monoxide. In this study, the factors that can improve the cycle performance have been discussed through the change in the configurations of the electrode and the electrolyte. The electrode using the carboxymethyl cellulose (CMC) binder shows the best cycle performance compared to the conventional binders. The electrode sing the CMC and styrene-butadiene rubber (SBR) binder not only has almost the similar cycle characteristics with the electrode using the CMC binder but also has the better rate capability. When the fluoroethylene carbonate (FEC) is used as an electrolyte additive, the cycle life is improved. However, the electrolyte with 5 wt% of FEC is appropriate because the rate capability decreases when the content of FEC is increased to 10 wt%. In addition, when the mass loading of the electrode is lowered, the cycle performance is greatly improved. Also, enhanced cycle performance is achieved using the roughened Cu current collector polished by abrasive paper.

• Journal of the Korean Applied Science and Technology
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• v.27 no.3
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• pp.257-265
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• 2010

This study concerned about "Gemini type co-surfactant" which has very interesting properties with new components. They were synthesized by reaction of diethylene glycol monoethyl ether and dicarboxylic acid. The structure could be comfirmed with FT-IR and $^1H$-NMR. Surface active properties such as surface tension, evaluated cmc, cloud point, emulsing power were measured respectively at given conditions. Their surface tensions in the aqueous solution were decreased to 33~35 dyne/cm, which was lower than 39 dyne/cm of SDS, and their cmc values evaluated by surface tension method were $5.0{\times}10^{-1}\sim7.5{\times}10^{-1}$ mol/L. And the emulsifying power was excellent in jojoba oil. All of the synthesized Gemini surfactants possessed good water solubility and their cloud point were $48\sim58^{\circ}C$. As results, Gemini surfactants which were synthesized are expected to be applied as O/W emulsifiers.

• Applied Biological Chemistry
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• v.36 no.4
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• pp.296-303
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• 1993

Response surface methodology was employed to investigate the conditions for separating water-soluble proteins from egg yolk using sodium alginate, propylene glycol alginate (PGA), sodium carboxymethylcellulose (CMC) and pectin which are approved as food additives. Effects of plysaccharide concentration and pH of the reaction system on protein and lipid contents in the supernatant were evaluated at respectively five and three levels of concentration and pH using rotatable hexagon design. Statistical analysis showed that pH of the system was a more important factor than polysaccharide concentration as it significantly affected all two responses. Separating conditions established by a graphical optimization technique were $0.23{\sim}0.25%$ of sodium alginate at $pH\;5.9{\sim}6.0$, $0.15{\sim}0.17%$ of PGA at $pH\;4.3{\sim}4.5$, $0.30{\sim}0.25%$ of CMC at pH 3.0, and $0.09{\sim}0.10%$ of pectin at $pH\;5.6{\sim}5.8%$.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.11a
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• pp.46-50
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• 1996

Die sinking Electrical Discharge Machining(EDM) of TiC/Al$_2$O$_3$Ceramic Matrix Composite(CMC) was conducted for positive and negative polarity according to the change of current and Duty Factor(DF). Also FEM analysis about temperature distribution of workpiece by one spark was executed. Maximum surface roughness( R$_{max}$ ) and SEM photographs of the EDMed surface for different conditions were evaluated. Higher Material Removal Rate(MRR) was obtained for negative polarity than positive one. Better surface morphology was found as the current is decreased, but the MRR was also decreased. From the SEM photographs, the size of melt cavity due to one spark is about 100 to 150${\mu}{\textrm}{m}$ in diameterer

• Journal of the Korean Applied Science and Technology
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• v.15 no.2
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• pp.11-24
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• 1998

All the surface activities including surface tension, foaming power, foam stability, emulsifying power, dispersion effect, and detergency were measured and critical micelle concentration(cmc) was evaluated in dilute aqueous solution. The cmc evaluated by the Ring method was $10^{-3}{\sim}10^{-4}mol/L$ in case of monoesters, and $10^{-3}{\sim}5.0{\times}10^{-5}mol/L$ in case of diesters, respectively. Surface tension of the aqueous solution was decreased to $45{\sim}50dyne/cm$, showing the tendency that the ability of lowering the surface tension was dependent on increasing of carbon atom number in alkyl chain. Foaming power of all the monoesters was better than that of diesters. while foam stability of diesters was to the contrary. Emulsifying power of soybean oil or benzene was specially expected to be good for emulsifiers in industrial application fields. HLB values of monoesters and diesters evaluated by Griffin's method were in the range of 8 to 12. Dispersion property of ferric oxide was stable in the range of $4.5{\times}10^{-5}{\sim}5.0{\times}^{-4}mol/L$ in case of monoesters, and $10^{-5}{\sim}10^{-4}mol/L$ in case of diesters.