• Proceedings of the PSK Conference
• /
• 2002.04a
• /
• pp.182.1-182.1
• /
• 2002

• Proceedings of the KAIS Fall Conference
• /
• 2000.10a
• /
• pp.245-250
• /
• 2000

고습도 또는 결로시 내수성을 지니는 저항형 습도센서를 제조하기 위하여 vinylbenzyl tributyl phosphonium chloride를 포함하는 4원 공중합체를 합성하여 저습도와 고습도 범위에서 측정이 가능한 습도센서용 감습막을 제작하였다. 1,5-dibrompentane과 4차 염화 가교 반응을 통하여 최종 저항형 습도센서를 제작하였다. 감습막은 알루미나 기판에 한 쌍의 금 paste가 인쇄된 전극을 사용하였으며, 감습막은 다양한 비율의 vinylbenzyl tributyl phosphonium chloride, 2-(dimethlamino)ethyl methacrylate, 2-ethylhexyl acrylate, 그리고 [2-(methacryloyloxy)ethyl]trimethyl ammonium chloride 등을 이용하여 제조하였다. 감습막은 micro-syringe를 이용하여 도포하였으며 건조 oven에서 50℃에서 6시간 동안 가교반응을 진행하였다. 습도센서의 임피던스 특성은 2-(dimethylamino)ethyl methacrylate 또는 [2-(methacryloyloxy)ethyl]trimethyl ammonium chloride의 함량이 증가할수록 감소하였다. vinylbenzyl tributyl phosphonium chloride / 2-(dimethylamino)ethyl methacrylate / 2-ethylhexyl acrylate / [2-(methacryloyloxy)ethyl]trimethyl ammonium chloride의 조성비가 4/4/1/1인 공중합체의 경우 30-90%RH 범위에서 2.64 ㏁ - 3.11 ㏀의 임피던스 특성을 보였으며 우수한 직선성과 낮은 히스테리시스 나타내었다.

• Polymer(Korea)
• /
• v.27 no.2
• /
• pp.129-134
• /
• 2003

It has been known that the intercalation of long alkyl chains in montmorillonites (MMT) increased the hydrophobicity as well as gallery spacing of UT, which has influenced on the exfoliation behavior of various polymers. A series of organophilic MMTs were synthesized from the water/isopropyl alcohol solution of MMT with ammonium salts of various alkyl amines. The properties of obtained MMTs such as thermal decomposition temperature, gallery spacing as well as hydrophobic property were investigated. The X-ray diffraction experiments on organophilic montmorillonite demonstrated that the increase of length of alkyl substituent resulted in increase in the spacing between silicate layers, which was ranged from 13.1 to 29.4 $\AA$. On the other hand, introduction of (di-, tri-) alkyl substituents in ammonium salts decreased water absorption of organophiplic montmorillonite to 2.7%.

• Journal of Korean Society for Atmospheric Environment
• /
• v.11 no.2
• /
• pp.191-198
• /
• 1995

In order to evaluate the distribution and behaviour of atmospheric particulate metals in high-altitude area, we collected 22 aerosol samples using a high volume air sampler at Soback Mt. Meteorological Observation Station from Jan. to Nov. 1993 and analysed for metals (Al, Fe, Mg, Na, Ca, Mn, Co, Ni, Cu, Zn, Cd, and Pb) with ICP/AES and ICP/MS. Although sampling site is located in high-altitude and far from local sources of atmospheric pollutants, enrichments of metals are 2 times higher than those of western coastal reural area. This fact may imply that of metallic pollutants in the coastal rural site were came from further western side (e.g. China), atmospheric metals in this study area contain the signal of metropolitan cities located in the main wind direction (NNW). Sea salts are negligible in the aerosol particle population because reference elements of sea salts (Na, Mg) are all originated from soil particles. The contents of soil particles in aerosols are highest in spring and lowest in winter. Atmospheric enriched elements (Ni, Cu, Zn, Cd and Pb) are diluted with soil particles, especially during the yellow sand period. The results of factor analysis suggest possibility of interpreting their chemical significance in terms of sources (soil, pollutants) and gas-particle conversion processes (formation of ammonium sulfates, ammonium nitrates and/or their mixtures).

• Journal of the Korean Applied Science and Technology
• /
• v.32 no.1
• /
• pp.48-55
• /
• 2015

IMO to issue some restricted maritime legislation for reducing the adverse environmental impacts arising from such ship exhaust emissions. According to the IMO policy, every ship entering the Baltic SECAs has to equip the gas cleaning scrubber. The discharged waste solution by gas cleaning scrubber contains many types of salts, which to recover some valuable materials before disposal. This study try to achieve valuable salts including AN and AS throughout a few process such as selective organic solvents salting out, low temperature extraction and thermal evaporation. Amongst them, Thermal evaporation with repetition extraction using inorganic solvent was the most optimum to purify the extracted AN. This valuable salt was evaluated by Elemental analysis and Differential scanning calorimetry.

• Applied Chemistry for Engineering
• /
• v.17 no.3
• /
• pp.286-290
• /
• 2006

New quaternary ammonium chlorides, [alkyldimethyl-[5-(2-phenylthiazol-4-yl]-1,3,4-oxadizol-2-ylmethyl]quaternary ammonium chlorides (ADOQACs): 6] were obtained with high yields by the reaction of compound 5 with N,N-dimethylalkyl amines in isopropyl alcohol. The structures and physical properties of the synthesized compounds were investigated and those surface-active properties were measured. The surface tension ($\gamma_{cmc}$) and the minimal inhibitory concentration (MIC) of compound 6 were found to be influenced by the number of alkyl chain carbon. Especially, compounds 6c and 6d exhibited high anti-bacterial activities and good surface-active properties.

• Polymer(Korea)
• /
• v.39 no.1
• /
• pp.122-129
• /
• 2015

Recently, the development of a new class of anti-fouling paint resin which has excellent anti-fouling performance and no persistence in the marine ecology is necessary. In this study, we first polymerized polyurethanes (PUs) as the other type of matrix which have carboxylic acid groups by using poly(ethylene glycol) (PEG), 4,4'-diphenylmethane diisocyanate (MDI), and 2,2'-bis(hydroxyl methyl)-propionic acid (DMPA). And next, we synthesized final resins having quaternary ammonium salts on pendant acid groups of PUs. After synthesis, the physical self-polishing property of resin by the measurement of reduced thickness in sea water was tested. The mechanical property of antifouling paint resin was good when the molecular weight of PEG was 600 or less. It was confirmed that the adhesion of PU resin was deteriorated when the content of quaternary ammonium salt was incorporated over specific value.

• Journal of the Korean Chemical Society
• /
• v.20 no.3
• /
• pp.185-192
• /
• 1976

Equivalent conductances of ammonium salts such as $NH_4Cl,\;CH_3NH_3Cl,\;(CH_3)_2NH_2Cl,\;(CH_3)_3NHCl\;and\;(CH_3)_4NCl$ have been measured in methanol-water mixtures of various composition (0.0${\sim}$0.6-mole frcation: m. f.) in the concentration range from 0.01 to 0.04 M at $25^{\circ}C$, and limiting equivalent conductances (${\Lambda}_0$) are determined by the analysis of Fuoss Onsager's semiempirical equation.The experimental results are discussed in terms of varing the size of ${\Lambda}_0$ due to the salts species and solvent composition. It has been observed in quite common over all salts that ${\Lambda}_0$ decreases with the increase of m. f. methanol, and the maximum decrement in ${\Lambda}_0$ shows between water and 0.1 m. f., while the plot of ${\Lambda}_0$ vs. m. f. goes through a minimum at 0.4 m. f. and then turns slightly upward. On the other hand, the ${\Lambda}_0$ decrease with the increase of the size of ammonium cation and the larger values ${\Lambda}_0$ are showed in comparison with those of values observed for the corresponding $n-RNH_3Cl$ under the same experimental procedure. All these behaviors are considered to be closely correlated with the structures of solvents and solutes and the significant similarities are compared with the behaviors of partial molar volumes for amine salts in same solvent system.

• Textile Coloration and Finishing
• /
• v.20 no.3
• /
• pp.39-56
• /
• 2008

A wide variety of materials including aldehydes, cationic agents, alcohols, peroxygens, phenols and chlorinated phenols, metal ions are being employed as biocides. Among three levels for biocidal functions (sanitization, disinfection and sterilization), disinfection is an enough level for antimicrobial textiles. In terms of antimicrobial agents for textile applications, quaternary ammonium salts (QAS), chitosan, metal and metal salts, N-halamine based materials are developed with numerous research and the positive ions of those materials may result in disinfection of microorganisms. Photocatalysts, especially titanium dioxide (titania) produces the hydroxyl radical (${\cdot}\;OH$) which causes inactivation of microorganisms after UV radiation, have been used for antimicrobial applications.

• KSBB Journal
• /
• v.6 no.4
• /
• pp.337-344
• /
• 1991

The liquid-liquid extraction of lipase A from Candide cylindracea and lipase B from porcine pancrease was carried out using reversed micellar organic solvents. Effects of various factors such as ionic strength, pH, and species and concentration of surfactant, on lipase solubilization were studied. A cationic surfactant cetyl-trimethyl ammonium bromide (CTAB) in isooctane/nhexanol(1:1) was found to be an effective solvent and its optimum concentration was 50 mM. KCl among various salts tested was the most effective and the efficiency of solubilization of lipase increased with decreasing the ionic strength of salts. The maximum activity and solubiliz ation of protein were obtained at pH 8. The stripping efficiency has a maximum value at pH 4 and increases with KCl concentration in the range of 0.2∼1.0 M. After the solubilization and stripping, the overall recovery efficiency of mass and specific activity of lipases was 62% and 66%, respectively.