간행물

한국응용과학기술학회지 KCI 등재 The Korean Society of Applied Science and Technology

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Vol.18 No.1 (2001년 3월) 10

1.
2001.03 구독 인증기관 무료, 개인회원 유료
Theoretical model has been studied for the transport phenomena of molecules in the system where an electric potential is applied to the system in the axial direction. The effect of electrophoretic convection in the polymeric media is significantly contributed to separate large ionic-molecules because the conformation of large ionic-molecule quickly orients in the field direction. The dependence of the transport in the polymeric media upon field intensity and molecular size aids in understanding the transport of large ionic-molecule in the system, since the convective velocity of large ionic-molecule is accelerated inside a porous material. The transport distance of individual large ionic-molecule can be predicted using the reptation theories.
4,000원
2.
2001.03 구독 인증기관 무료, 개인회원 유료
White emission is important for applying organic EL devices to full-color flat panel display and backlight for liquid crystal display. In order to obtain white emission, the use of a light-emitting material which shows the white emission by itself is advantageous for these applications because of its high reliability and productivity. A chelate-metal complex such as zinc bis(2-(2-hydroxyphenyl) benzothiazolate) (Zn(BTZ)2 was known to emit white light with a broad electroluminescence. In this study, the electroluminescent characteristics of Be(BTZ)2 and Mg(BTZ)2, as well as Zn(BTS)2 were investigated using organic electroluminescent devices with the structure of ITO/TPD/ Be(BTZ)2, Mg(BTZ)2, or Zn(BTZ)2/Al. It was found that the device containing Be(BTZ)2 showed the highest power efficiency.
4,000원
3.
2001.03 구독 인증기관 무료, 개인회원 유료
Eu(III) exhibits one electron-transfer reduction at E1/2 = -0.564 V(vs. Ag/AgCl) and the hypersensitive peak at 615 ㎚ corresponding to 5D0→7F2 transition in 0.1 M LiClO4 aqueous solution. Upon the addition of 2,6-pyridine dicarboxylic acid(PDA) to the Eu(III) aqueous soultion, the reduction potential shifts negatively and the PDA, and the Eu(III)-PDA complex emits great fluorescence than free-Eu(III) ion at 615 nm. The results are interpreted in term of the electrochemical and spectrofluorometric studies.
4,000원
4.
2001.03 구독 인증기관 무료, 개인회원 유료
Acrylic quarternary polymers were synthesized to prepare high-solid coatings. Acrylic resins were synthesized by the radical polymerization of n-butyl acrylate, methyl methacrylate, 2-hydroxyethyl methacrylate and acetoacetoxyethyl methacrylate. From the results of experiment on reaction condition to get high-solid acrylic resins with 70% solid content and viscosity of 1200cps, it was found that di-tert-amyl peroxide among the four types of initiators have lower viscosity and higher degree of conversion. The optinum initiator amount, chain transfer agent, reaction temperature and the dropping time were 5wt%, 4wt%, 150℃ and 5hrs, respectively.
4,000원
5.
2001.03 구독 인증기관 무료, 개인회원 유료
An acrylic resin was synthesized with several monomers, styrene(St), 2-hydroxyethyl methacrylate(2-HEMA), n-butyl acrylate, methyl methacrylate, and acetoacetoxyethl methacrylate(AAEM) to prepare a high-solid coatings. Then, a high-solid acryl/melamine coatings was prepared by curing the acrylic resin with a curing agent, hexamethoxymethylmelamine(HMMM). The curing behavior of the acrylic resin with HMMM was investigated by the Ozawa method using DSC. For AAEM/HMMM and 2-HEMA/HMMM curing reactions, activation energies were 33.01 and 27.12 kcal/mol and frequency factors were 9.54×1015 and 1.53×1013 min-1, respectively. From the results, it was found out that 2-HEMA showed higher reactivity with the curing agent than AAEM.
4,200원
6.
2001.03 구독 인증기관 무료, 개인회원 유료
Curing reaction was carried out with the acrylic resin (ACR) [n-butyl acrylate/atyrene/2-hydroxyethyl methacrylate/acetoacetoxyethyl methacrylate (AAEM)] synthesized before and a curing agent, hexamethoxymethylmelamine (HMMM). With rotational rheometer, the effect of catalysts on curing rate of acrylic resin/melamine was examined. Among the four catalysts used, p-toluene sulfonic acid showed the highest reactivity, and the optimum amount of catalyst was 0.5 phr. It was observed that in the ACR/HMMM curing reaction, gelation point was lowered with the increasing the amount of AAEM and HMMM in the ACR.
4,000원
7.
2001.03 구독 인증기관 무료, 개인회원 유료
Ultra-thin films of organic charge transfer complex were prepared on a hydrophilic substrate by Langmuir-Blodgett(LB) technique. In this study, the photoelectric properties of a LB film consisting of (N-docosyl quinolinium)-TCNQ(1:2) complex was investigated. The visible light(λ : 700 nm) of xenon lamp was illuminated on the LB films and light absorptivity and photoconductivity were observed. The photocurrent increased linearly and was saturated at the light intensity of 23 μW/cm2.
4,000원
8.
2001.03 구독 인증기관 무료, 개인회원 유료
These N-acyl amino acid surfactants is normally produced by reaction of acid anhydride with sodium l-glutamate hydrolysates under Schotten-Baumann condition i.e., in alkaline aqueous medium. To avoid using fatty acid chlorides, acylations were also carried out with the fatty acids themselves or with their methyl esters, but unfortunately these methods cannot be used in practice, dodecenyl succinic anhydride, was to be studied for their suitability as acylating agents the production if acylated glutamine hydrolysates. The surface activities including surface tension forming power, forming stability and emulsifying power were measured. The experimental results revealed that the products have a good emulsifying power. Thus, there derivatives will be expected to be used an emulsifying agent for O/W type cosmetic emulsion.
4,000원
9.
2001.03 구독 인증기관 무료, 개인회원 유료
Allylaliphatic carboxylate oligomers were prepared from polymerization giving allyl aliphatic carboxylates in the presence of potassium persulfate in methanol and the α-sulfonation of these allyl aliphatic carboxylates oligomers were carried by direct addition of dry sulfur trioxide. The dispersing performance of oligomer type anionic surfactants and SDS in the aqueous suspension of Fe2O3 and Tio2 particles were evaluated by particle size distribution and ξ-potential measurement. As results, the particles of Fe2O3 and Tio2 were flocculated by addition of small amount of oligomer type anionic surfactants and SDS, then the flocks redispersed by more addition oligomer type anionic surfactants and SDS. The dispersion and flocculation were observed in lower concentration range of oligomer type anionic surfactants than SDS.
4,000원
10.
2001.03 구독 인증기관 무료, 개인회원 유료
In search for several fatty acid with unusual structure in vegetable oils, we have found that unknown peaks were shown on GLC in the analysis of fatty acids of the lipids from the pulp of ripened jujube (Zizypus jujuba var. inermis) fruits. These fatty acids were identified as a series of cis-monoenoic acids with Ω-5 double bond system such as C14:1Ω5, C16:1Ω5 and C18:1Ω5, including Ω-7 fatty acid as C16:1Ω7 and C18:1Ω7, by GLC, solid-phase extraction silver ion-column chromatographic, GLC-mass spectrometric and IR techniques. First of all, total fatty acid methyl esters were resolved into saturated and branched fatty acid, monoenoic acid, dienoic acid, and trienoic acid fraction, respectively, with 100% dichloromethane (DCM), DCM/acetone (9:1, v/v) 100% acetone, and acetone/ acetonitrile (97:3, v/v) solvent system. Unknown fatty acids were included in the monoenoic fraction and were confirmed to have cis-configuration by IR. Picolinyl esters of monoenoic fatty acids gave distinct molecular ion peak and dominant diagnostic peaks, for example, m/z 317, 220 and 260 fragment for cis-C14:1Ω5, m/z 345, m/z 248 and 288 fragment for cis-C16:1Ω5 and m/z 373, m/z 276 and 316 fragment for cis-C18:1Ω5. In this way the occurrence of cis-C16:1Ω7 and cis-C18:1Ω7 could be deduced from the appearance of prominent fragments as m/z 345, 220 and 260, and m/z 373, 248 and 280. Level of total Ω-5 fatty acids amounted to about 30% in the fatty acid composition with the predominance of C16:1Ω5 (18.7~25.0%), in the semi-ripened and/or ripened samples collected in September 14 (C16:1Ω5 ; 18.7%, C14:1Ω5 ; 3.6% and C18:1Ω5 ; 3.0%), September 22 (C16:1Ω5 ; 25.0%, C14:1Ω5 ; 1.4% and C18:1Ω5 ; 2.6%), and October 7 (C16:1Ω5 ; 24.7%, C14:1Ω5 ; 7.7% and C18:1Ω5 ; 2.5%). However, the lipids extracted from unripened jujube in July and August contain these unusual fatty acids as low as negligible. It could be observed that the level of Ω-5 fatty acids in the pulps increased sharply with an elapse of ripening time of jujube fruits. Other monoenoic fatty acids with Ω-7 series, C16:1Ω7 (palmitoleic acid) and C18:1Ω7 (cis-vaccenic acid) could be detected. And in the lipids of the kernel and leaf of jujube, none of Ω-5 fatty acids could be detected.
4,200원