• Title/Summary/Keyword: metal salts

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Synthesis of Hydroxy-terminated Poly(propylene carbonate) (Hydroxy-terminated Poly(propylene carbonate)의 합성)

  • Jung, S.M.;Moon, J.Y.;Park, D.W.;Park, S.W.;Lee, J.K.
    • Applied Chemistry for Engineering
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    • v.9 no.2
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    • pp.273-277
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    • 1998
  • The synthesis of hydroxy-terminated poly(propylene carbonate)(HTPPC) was performed by the reaction of propylene carbonate(PC) with alcohol initiator using metal alkoxides, crown ethers and quaternary onium salts as catalysts. The effects of catalyst structure, types and concentration of alcohol, and solvent were investigated. Among the alkoxide catalysts tested, the ones with higher Lewis acidity and with more nucleophilic alkoxide anion showed higher catalytic activity. Mixed catalysts of metal alkoxied and crown ether showed higher conversion of PC than metal alkoxide alone. Quaternary onium salts of bulky cation exhibited higher catalytic activity. High polar solvent showed higher yield of HTPPC and the yield increased with the decrease of [PC]/[Initiator] ratio.

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Preparation and Chrominance of Metal Oxide Coated Titania/Mica Pearlescent Pigment (금속산화물이 코팅된 마이카 티타니아 진주광택 안료의 제조 및 색차변화)

  • Lee, Kwan-Sik;Kang, Kuk-Hyoun;Lee, Jin-Hee;Lee, Dong-Kyu
    • Journal of the Korean Applied Science and Technology
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    • v.30 no.2
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    • pp.233-243
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    • 2013
  • The inorganic pearlescent pigment have high physical and chemical stability, thus it is used in a variety field, which has better light stability, solvent resistance and thermostability. In this paper, we were synthesized the pearlescent pigment for cosmetics which was coated cobalt chloride for base of blue color metal oxide on mica titania substrate using hydrothermal synthesis method. To complement the color of the pigment by cobalt, pearl pigment were coated by different metal salt and cobalt ratio, to implement a variety of color value, depending on the kind of metal salts were synthesized. Synthesized pearlescent pigments appear various color as kind of added metal salt precursor and molar ration of cobalt and other metals. We controlled coating and color by composition of metal salt and type of metal salts, and that confirm the pigment characteristics of color changes through the analysis of color difference meter. Synthesized pigment was characterized by SPM, SEM, XRD, and EDS.

Preparation of Polymer-Metal Complexed Membranes using Ethylcellulose and Metal salts, and Their Characteristics of Gas Separation. (Ethylcellulose와 금속염을 이용한 고분자-금속 착체막의 제조 및 기체투과특성)

  • 변홍식;서성호;박병규;홍병표;백승욱;박영규
    • Membrane Journal
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    • v.13 no.3
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    • pp.200-209
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    • 2003
  • Polymer-metal complexed membranes were prepared by solvent evaporation method using ethylcellulose, platinum(II)acetylacetonate, and rhodium(III)acetylacetonate. The various composition of metal salt(0.3-4.0 wt%) were employed to obtain the optimum performance of final membrane. EC-metal complexed membranes were characterized by FTIR and scanning electron microscopy(SEM) to observe the morphology and the performance of oxygen, nitrogen, carbon dioxide, and methane gases was tested. It was shown that the metal salts enhanced the permeability of all gases without decrease of selectivity. However, it was found that Pt had more effects on the permeability of oxygen and nitrogen gases while Rh had more effects on the permeability of carbon dioxide and methane gases. EC-Pt complexed membrane(Pt 1.0 wt%) even showed the enhanced selectivity of oxygen/nitrogen(37%) due to the affinity characteristic of Pt to oxygen.

Salinity and Heavy Metal Contents of Solar Salts Produced in Jeollanamdo Province of Korea (전라남도 지역에서 생산된 천일염의 염도 및 중금속 함량)

  • Lee, Kang-Deok;Park, Jeong-Wook;Choi, Cha-Ran;Song, Hyun-Woo;Yun, Su-Kyoung;Yang, Ho-Chul;Ham, Kyung-Sik
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.36 no.6
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    • pp.753-758
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    • 2007
  • To assess the safety of solar salts of Jeollanamdo province where most of Korean solar salts are produced, 433 samples of solar salts in total were collected and analyzed for their contents of sodium chloride and heavy metals (lead, cadmium, arsenic and mercury). Sodium chloride contents ranged from 80 to 85% in 63% of solar salts analyzed. Lead was not detected in 77% of solar salt samples and showed a value of below the maximum permissible limit (2 ppm) in other samples. Cadmium was not detected in most samples (78%), and the other samples where cadmium was detected showed a value far below the maximum permissible limit (0.5 ppm) except for three ones. Arsenic was detected in only four samples, but their concentrations were far below the permissible limit (0.1 ppm). Mercury was not detected in all samples. There were some differences between producing areas in the levels of sodium chloride and lead of solar salts, but the contents of cadmium, arsenic and mercury did not show significant regional differences. These results clearly indicate that solar salts produced from Jeollanamdo province are safe in the aspects of lead, cadmium, arsenic and mercury contents.

Heavy Metal Contents of Marketing Salts and Bay Salts by Heating (시판 소금의 중금속 함량과 천일염의 온도변화에 따른 중금속 함량)

  • 홍광택;이종영;장봉기
    • Journal of environmental and Sanitary engineering
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    • v.11 no.3
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    • pp.79-84
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    • 1996
  • In order to determine the content of heavy metal in common salts, 35 bay salt samples, 7 refined salt samples, 7 fine salt samples, 5 bake salt samples and 5 bamboo bake salt samples were collected from old market in major cities. Heating bay salt 35 samples, it made heating bay salt of $500^{\circ}C$, /TEX>(34 samples), heating bay salt of $1000^{\circ}C$(35 samples). These were analysed for contents of lead(Pb), cadmium(Cd), iron(Fe) and zinc(Zn) by atomic absorption spectrophotometer. The results were as follows : Mean content of lead in bay salts was $0.124{\pm}0.035ppm$ refined salt was $0.130{\pm}0.019ppm$, fine salt was $0.073{\pm}0.036ppm$ bake salt was $0.097{\pm}0.023ppm$, bamboo bake salt was $0.117{\pm}0.020ppm$, heating bay salt was $0.063{\pm} 0.021ppm$ in $500^{\circ}C$, heating bay salt was $0.063{\pm}0.039ppm$ in $1000^{\circ}C$. And bay salt refined salt bamboo bake salt were not significant one another. Mean content of cadmium in bay salts was $0.031{\pm}0.008ppm$ refined salt was $0.032{\pm}0.003ppm$, fine salt was $0.037{\pm}0.005ppm$, bake salt was $0.169{\pm}0.117ppm$ bamboo bake salt was $0.079{\pm}0.052ppm$, heating bay salt of $500^{\circ}C$ was $0.030{\pm}0.029ppm$ heating bay salt of $1000^{\circ}C$ was $0.017{\pm}0.013ppm$. And bay salt refined salt, fine salt were not significant one another. Mean content of iron in bay salts was $1.025{\pm}0, 634ppm$, refined salt was $0.359{\pm}0.163ppm$ fine salt was $0.267{\pm}0.068ppm$, bake salt was $2.929{\pm}1.963ppm$, bamboo bake salt was $5.378{\pm}3.676ppm$, heating bay salt of $500^{\circ}C$ was $0.847{\pm}0.315ppm$ heating bay salt of $1000^{\circ}C$ was $0.991{\pm}0.868ppm$. And bay salt refined salt, fine salt, bake salt, bamboo bake salt were significant one another(p<0, 01). Mean content of zinc in bay salts was $0.253{\pm}0.154ppm$, refined salt was $0.263{\pm}0.091ppm$ fine salt was $0.187{\pm}0.015ppm$, bake salt was $0.166{\pm}0.034ppm$, bamboo bake salt was $0.282{\pm}0.064ppm$, heating bay salt of $500^{\circ}C$ was $0.253{\pm}0.085ppm$, heating bay salt of $1000^{\circ} C$ was $0.242{\pm}0.179ppm$. And bay salt refined salt fine salt, bake salt, bamboo bake salt were not significant one another.

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Accelerating Effect of Neutral Salts on Alkaline Hydrolysis of Poly(ethylene terephthalate) (I) - Cationic Effect - (중성염의 폴리에틸렌 텔레프탈레이트의 알칼리 가수분해 촉진효과에 관한 연구(I) - 양이온의 영향 -)

  • Do, Sung-Guk;Cho, Hwan
    • Textile Coloration and Finishing
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    • v.6 no.1
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    • pp.33-43
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    • 1994
  • In the present work, to clarify the mechanism of the neutral salt effect on the alkaline hydrolysis of PET, many salts with different cations like LiCl, NaCl, KCl, CsCl were added to the aqueous alkaline solutions. Then PET was hydrolyzed with aqueous solutions of many salts in alkali metal hydroxides under various conditions. Some conclusions obtained from the experimental results were summarized as follows. The reaction rate of the alkaline hydrolysis of PET was increased by the addition of neutral salts and In k was increased nearly linearly with the square root of ionic strength of reaction medium. This fact suggested that the ionic strength effect by Debye-Huckel and Bronsted theory was exerted on the reaction. The specific salt effect was also observed. The reaction rate was increased with the increase in the electrophilicity of cations of neutral salts, i. e., in the order of $Cs^+$/ < $K^+$/ $a^+$/ $i^$^+$. It was considered that the reaction rate was increased in the order of C $s^+$. < $K^+$. $a^+$. $i^+$. because the lowering effect of the cations on the negative charge of PET surface was increased with the electrophilicity of cations. It was thought that $E_{a}$ was increased because the cations of neutral salts decreased the negative charge of PET surface. It, however, was inferred from the increase in ${\Delta}$S* and the decrease in the ${\Delta}$G* that the cations of neutral salts associated with PET increased the collision frequency between carbonyl carbon and OH- ion and then accelerated the reaction rate.te.

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On Formation of Residual Carbon Layer in CuInSe2 Thin Films Formed via direct Solution Coating Process (직접 용액 코팅법에 의해 제조한 CuInSe2 에 잔존하는 탄소 불순물층 형성에 관한 연구)

  • Ahn, SeJin;Rehan, Shanza;Eo, Young-Joo;Gwak, Jihye;Yoon, Kyunghoon;Cho, Ara
    • Current Photovoltaic Research
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    • v.2 no.1
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    • pp.36-39
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    • 2014
  • Formation mechanism of residual carbon layer, frequently observed in the $CuInSe_2$ (CIS) thin film prepared by direct solution coating routes, was investigated in order to find a way to eliminate it. As a model system, a methanol solution with dissolved Cu and In salts, whose viscosity was adjusted by adding ethylcellulose (EC), was chosen. It was found that a double layer, a top metal ion-derived film and bottom EC-derived layer, formed during an air drying step presumably due to different solubility between metal salts and EC in methanol. Consequently, the top metal ion-derived film acts as a barrier layer inhibiting further thermal decomposition of underlying EC, resulting a formation of bottom carbon residue layer.