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        검색결과 2,503

        1981.
        2002.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Oligomer type anionic surfactants(RmM-Na or RmD-Na were synthesized from C8~C16 long chain alkylvinylether and maleic anhydride (or maleic diethylether). And also their fluorescent anionic surfactants (RmF- Na) were obtained from alkali neutralization which opens the lactone ring of the condensing materials produced by maleic anhydride alkylvinylether copolymer and 3-aminophenol. The measurement results for the surface active properties of water soluble oligomer type anionic surfactants with fluorescent structure (RmF-Na) exhibited a remarkable surface tension lowing property, foam breaking property, and a ernulsing power.
        4,200원
        1982.
        2002.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The cutaneous tolerability of detergent formulations can be improved by means of suitable additives. They complex the surfactant molecules lowering the concentration of their free monomeric species. Proteins derivatives used as additives for detergency are usually prepared by partial hydrolysis of plant reserve proteins. The main purpose of the hydrolytic cleavage is to make them water soluble and suitable for liquid products. Water solubility and stability are obtained by means of complexation with surfactants which also increase their actual hydrophobicity, an important parameter affecting cosmetic properties of proteins. Transepidermal water loss (TEWL) and electric capacitance (EC) have been adopted as investigation technigues to evaluate the skin integrity/damage in vitro tests, The performance of native wheat protein / surfactant complexes has been compared with traditional protein hydrolysates as detergent additives. The results show a noticeable reduction of skin irritation in surfactant formulations with addition of native wheat protein.
        4,000원
        1983.
        2002.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The polyimide(PI) Langmuir-Blodgett(LB) ultra thin films were prepared by imidizing the PAAS LB films of PMDA and benzidine system with a thermal treatment at 250℃ for 30min, where the PAAS LB films were formed on substrates by using LB technique. The thicknesses of one layer of PAAS and PI LB film that deposited at the surface pressure of 27mN/m were 20.9 and 4A, respectively. At low electric field, ohmic conduction(I∝ V) was observed and the calculated electrical conductivity was about 4.23×10-15~9.81×10-15S/cm. The dielectric constant of LB film was about 7.0.
        4,000원
        1984.
        2002.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We have seen the effects of buffer layer in organic light-emitting diodes(OLEDs) using poly(N-vinylcarbazole)(PVK) depending on a concentration of PVK. Polymer PVK buffer layer was made using spin casting technique. Two device structures were fabricated; one is ITO/TPD/Alq3/Al as a reference, and the other is ITO/PVK/TPD/Alq3/Al to see the effects of buffer layer in organic light-emitting diodes. Current-voltage-luminance characteristics and an external quantum efficiency were measured with a variation of spin-casting rpm speeds and PVK concentration. We have obtained an improvement of external quantum efficiency by a factor of four when the PVK concentration is 0.1wt% is used. The improvement of efficiency is expected due to a function of hole-blocking of PVK in OLEDs.
        4,000원
        1985.
        2002.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Natto is a Japanese traditional food made from whole soybeans by the fermentation of Bacillus natto. The purpose of this study was to investigate the effect of Natto mucilage on lipid metabolism in rats. The levels of total cholesterol, LDL-cholesterol and triglyceride in serum of rats fed Natto mucilage diets were lower than those in control rats, but serum HDL-cholesterol and phospholipid were higher than those in control rats. The results indicate that Natto mucilage may have more beneficial roles in lipid metablism because it decreased serum cholesterol and increased bilirubin excretion.
        4,000원
        1986.
        2002.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Microemulsion is stable to aggregation, sedimentation, fusion and has 3nm~200nm of particle size which is transparent and semitransparent. The isoflavone as a derivatives of Flavone is colorless crystalline compounds. It has similar basic structure to steroid materials which is hormone that acts to skin physiological phenomenon. On this study, we tried to search and demonstrate system content rate of dermal translocation system for cosmetics using O/W type microemulsion containing isoflavone. We manufactured O/W microemulsions by phase inversion emulsification method. It's was found that POE(20) monostearate with HLB value 14 caused microemulsion to be formed, which had 4nm~18nm of average diameter and 3nm~33nm of particle size distribution. Apparent viscosities of the microemulsions have increased in proportion to add surfactant dose.
        4,000원
        1987.
        2002.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We carried out this experiment to observe electrochemical properties for LB films of phospholipid(Dilauroyl-L-α-Phosphayidylcholine) and 4-octyl-4'-(5-carboxypentamethylene-oxy)azobenzene mixture by the cyclic voltammetry. LB films of 8A5H and 8A5H-DLPC(1:1, 2:1) were deposited by using the Langmuir-Blodgett method on the ITO glass. We determined electrochemical measurement by using cyclic voltammetry with a three-electrode system, An Ag/AgCl reference elect rode, a platinum wire counter electrode and LB film-coated ITO working electrode measured in 0.1, 0.5, and 1.0 mol/L NaClO4 solution. A measuring range was reduced from initial potential to -1350 mV, continuously oxidized to 1650 mV and measured to the initial point. The scan rate were 50, 100, 150 and 200 mV/s. As a result, LB films of 8A5H 8A5H-DLPC appeared irreversible process caused by only the oxidation current from the cyclic voltammogram.
        4,000원
        1988.
        2002.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We carried out this subject to observe photoisomerization using 1,2-dioleoyl-sn- glycero-3-phosphocholine(DOPC) mixed with fatty acid containing azobenzene group which has reversible to cis-trans by light irradiation. Spreading solutions for the LB films were prepared in chloroform(5.0×10-5mol/L).We investigated the photoisomerization and property of the organic ultra thin film of fatty acid containing azobenzene was prepared on the hydrophilic ITO(idium tin oxide) glass plate by LB method. As a result, the absorption spectra of 8A5H and DOPC of mixture LB films was induced to photoisomerization by alternating irradiation of ultraviolet and visible light, because the condensation of pure azobenzene monolayers was loosened by the introduction of phospholipid into the monolayers, and the molecular high aggregation in pure azobenzene monolayers is also weakened by the introduction of phospholipid. We found that it was reversibly induced to cis-trans photoisomerization in several solvents and mixture LB films.
        4,000원
        1989.
        2002.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Copolymerization of α-Methylstyrene(AMS) with Acrylonitrile(AN) was carried out with benzoylperoxide(BPO) as an initiator in toluene at 80℃ in a continuous stirred tank reactor. Reaction volume and residence time were 0.6 liters and 3 hours, respectively. The monomer reactivity ratios, rAMS and rAN determined by both the Kelen-Tüdös method and the Fineman-Ross method were rAMS=0.16(0.14), rAN=0.04(0.06). The cross-termination factor Φ of the copolymer over the entire AMS composition ranged from 0.75 to 0.92. The Φ factors of poly(AMS-co-AN) were increased with increasing AMS content. The simulated conversions and copolymerization rates were compared with the experimental results. It was observed that the average time to reach dynamic steady-state was three times the residence time.
        4,000원
        1990.
        2002.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Two PU flame-retardant coatings, 2,3-DBPO/N-l00 (DBPON) and 2,3-DBPO/IL (DBPOI), were prepared by curing 2,3-dibromo modified polyester (2,3-DBPO) with isocyanate curing agent Desmodur N-l00 (or Desmodur IL) at room temperature. The physical properties and flame-retardancy of the two coatings were tested and compared. As a result, the pot-life, yellowness index, lightness index difference, 60˚ specular gloss, cross-hatch adhesion, viscosity, and accelerated weathering resistance of DBPON were better than those of DBPOI; the fineness of grind of the two coatings were the same; and the drying time, hardness, and abrasion resistance of DBPOI were better than those of DBPON. The flame retardancy of the flame-retardant coatings increased with the content of the flame retarding component, 2,3-dibromopropanoic acid (2,3-DBP); and the LOI values of the two coatings were in a range of 27~29% when the content of 2,3-DBP was 30wt%.
        4,000원
        1991.
        2002.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        It is a great role that the character of man or woman could be distinguished by hair on the aspect of ornament. Hair will be support of beautifulness of human being in various permanent wave by many kinds of its drugs. Hair is based upon the skin which enroll the body of high living animals and have multiple membrane structure. This study used rat and the effects of commercial permanent wave products to skin which are composed with thioglycolic acid and bases. Results are as follows. Permanent wave penetrated to 4 hours later with steady state in skins and was not significant changeable after 20hr later. In case of neutralizer with thioglycolic acid lag time and permeability coefficient in healthy skin is 3.38hr and 0.094μg/cm2 · hr, it old skin is 3.48hr and 0.129μg/cm2 · hr, and it wounded skin is 4.72hr and 0.158μg/cm2 · hr. In conclusion, lag time and permeability coefficient in old skin and wounded skin are faster than healthy skin. In vivo which was studied by general time and method of permanent wave. We notified that fine rinkle and rash of skin were changeable in the case of treating with permanent wave drugs than normal skin. We can see even rash and eruption by the naked eye.
        4,000원
        1992.
        2002.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, it should be mentioned that Lipid-LCG can be prepared with the main compound of hydrogenated lecithin in oil-in water emulsion. The results of its physical property and stability are as follows. First, the best suitable compositions of Lipid-LCG are made from 4.0wt% of the hydrogenated lecithin, 4.0wt% of cetostearyl alcohol as emulsifier and gelling agent, 3.0wt% of butylene glycol and 2.0wt% glycerin as moisturizers, 3.0wt% of cyclomethicone, 3.0wt% of isononyl-isononanoate, 3.0wt% of capric/caprylic triglycerides, 3.0wt% of macadamia oil as emollients. Second, As the optimum conditions to form Lipid-LCG, which figured out 6.0 ± 1.0 for pH level, 32kg/mm, min for hardness to make a .essence to be formed the ternary phase of liquid crystal(multi-lamellar type). Third, as the analytical result of this system, it obtained that particle size is 1~8μm level, and is certified with it at 400 and 1,000 magnifications by microscope. The stability of Lipid-LCG is very stable on condition of a low temperature (4℃), a room temperature (25℃) and a high temperature (40℃), which is not to be split in for a long time(for 3-month). We produced our own moisturizing essence, which has a good affinity to skin by means of this system.
        4,000원
        1994.
        2001.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The critical micelle concentration (CMC) at which micelles start to form from a surfactant solution is usually measured in terms of conventional concentration units. However, the thermodynamic potentials are expressed in terms of mole fraction XCMC and XCMC cannot be directly measured experimentally. The Gibbs free energy, δG*mic, in particular is related to XCMC through δG*mic = RTlnXCMC. When it comes to CMC, the molar CMC, CCMC, differs only by the proportionality C-1w with Cw being the molarity of water. Hence, CCMC is found to be a proper representation of CMC. However, in calculation of δG*mic and other thermodynamic potentials from the CMC, XCMC or CCMC/Cw should be used.
        4,000원
        1995.
        2001.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        To prepare an acrylic type pressure-sensitive adhesive, quarternary polymers were synthesized from butyl acrylate (BA), 2-ethyl hexyl acrylate (2-EHA), methyl methacrylate (MMA), and 2-hydroxy ethyl methacrylate (2-HEMA). The quarternary polymers were identified by FT-IR and Molecular weight was measured by Gel Pearmeation Chromatography. Also, viscosity, solid content and peel strength were examined. The peel strength was 160 gf/25 mm when the volume ratio of feed monomer to solvent was 1.3:1, and the ratio was relevant to commercial usage. The pot life of adhesive was 30 sec at the 50 m/min of heat treatment rate at, and it indicated that the minimum drying time was 30 sec. In weathering resistance test, peel strength of 160~180 gf/25 mm after 1000 h, with no residual remains on the adhesive surface.
        4,000원
        1996.
        2001.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Our study is aimed at proposal of systematic verification method of molecular structure using measuring method of selective ionic determination and spectrometry on 34 kinds of surfactants such as sodium dodecyl sulfate(SDS) which are most widely used today. In the IR spectrum, unsaturated fatty acids reveal themselves by HC= at 3000~3020cm-1, and intensity of 720cm-1 depends on carbon length of alkyl group. Also ethylene oxide(EO) adducts exhibit weak characteristic bands by -CH2-CH2-O at 1350, 1100 and 950cm-1. Isethionate can be distinguished from diester succinate by intensity ratio of 1740 and 1200cm-1 spectrums, the ratio of latter is close to 1 due to 2 carboxylate radical in diester succinate. Quaternary ammonium salts exhibit characteristic band of C4N+ at 1000-900㎝-1. In the case of dialkyl dimethyl ammonium salts in quaternary ammonium surfactants, the spectrum of 3000cm-1 by N-CH3 collapses to a very weak band at 3020cm-1. In ammonium heterocyclic derivatives, pyridinium salts show characteristic bands at 1640 and 1460cm-1, while imidazolinium salts exhibit characteristic band at 1620-1610cm-1. In the characteristic spectrum at 1080-1050cm-1 on OH radicals of the alkyl esters, primary alcohol appears as weak band and the 2 bands show in almost same intensity when primary and secondary alcohols exist together in one molecule. Also, alkyl ester of polyhydric alcohols appears as various broad band.
        4,000원
        1997.
        2001.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Emulsified transesterification of soybean oil into biodiesel was investigated using potassium hydroxide and sodium methoxide catalysts with methyl glucoside oleic polyester as a methanol-in-oil emulsifier. The transesterification reaction conditions were optimized to obtain high yields of fatty acid methyl esters of the quality defined by biodiesel standards. The developed process resulted in 95~96% of overall yield from soybean oil by alkali-catalyzed methanolysis at 45℃ of reaction temperature with 6:1 of methanol-to-oil molar ratio and 1(v/v)% methyl glucoside oleic polyester in the presense of 0.8wt% KOH and 1.2wt% NaOCH3.
        4,000원
        1998.
        2001.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Zinc complexes with Bis[2-(o-hydroxyphenyl) benzothiazolato ligands (ZnPBS-0) and Bis[2- (o-hydroxynaphthyl) benzothiazolato ligands (ZnPBS-05) were synthesized, and luminescent properties of these materials were investigated. The emission band found that it strongly depends on the molecular structure of introduced ligand and was tuned from 525 nm to 535 nm by changing the ligand structures. Spreading of the π-conjugation in 2-(o-hydroxyphenyl) group gives rise to a blue shift. On the other hand, spreading of the π-conjugation in benzothiazole groups leads to a red shift. The EL properties also showed good consistency with their differences of ligand structure. Bright-blue EL emission with a maximum luminance of 8300 cd/m2 at 11V was obtained from the organic light - emitting diodes (OLEDs) using ZnPBS-0 as emitting layer. It was also found that the newly synthesized materials were suitable to be used as emitting materials in organic EL device.
        4,000원
        1999.
        2001.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The liquid body foam which added the garlic extract, differs for clothes and kitchen detergent, industrial and domestic detergent, and it has various characteristics as a soft detergent for bath and hair product. The contents of various characteristics in this experiment have tested for the foam formation force, the moisture force and the antimicrobial force. In case of this product adding garlic extrat, we could know the three characteristics. In first case to increase the concentration of Sunfom-S, we could know that the foam formation force increases following to it. In second case to increase the concentration of propylene glycol, we could know that the moisture force increases following to moisturing agent. In third case to increase the concentration of garlic extract, we could know that the antibiosis and preservation efficacy appears between 3.0-4.0wt% and the sterilization efficacy appears more than 5.0wt%. According to the result of this experiment, we could recognize the characteristics concerning to quality of this product.
        4,000원
        2000.
        2001.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A series of microcapsule were synthesized by using several PCM(Phase Change Material) as a core material and gelatin/arabic gum, melamine/formaldehyde as a shell material. Coacervation technique and in situ polymerization were adopted in synthesizing microcapsules. In the microencapsulation by coacervation, tetradecane and octadecane were used as core materials. In the microencapsulation by situ polymerization tetradecane, pentadecane, hexadecane, heptadecane, octadecane, and nonadecane were used as core material. The synthesized microcapsule was examined to observe the shape of the microcapsule. The particle size analysis was performed by particle size analyzer. The thermal properties(e.g. melting point, heat of melting, crystallization temperature, heat of crystallization, differences between melting point and crystallization temperature) were obtained by DSC(Differential Scanning Calorimeter). The stirring rate effect was investigated during the microencapsulation. It was found that with increasing the stirring rate much smaller microcapule was produced. However, this did not necessarily lead to formation of spherical microcapsule.
        4,300원