• Bulletin of the Korean Chemical Society
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• 제34권9호
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• pp.2597-2603
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• 2013

The reactions of hydrated $CdCl_2$, $MnCl_2$, and $NiCl_2$ with 2,2'-bipyidine-3,3',6,6'-tetracarboxylic acid ($H_4bptc$) afforded the mononuclear [$Cd^{II}(H_2bptc)(H_2O)_3]{\cdot}H_2O$ (1), linear $\{[Cd(H_2bptc)(H_2O)]{\cdot}3H_2O\}_n$ (2), 3-D heterobimetallic $[NaCd(Hbptc)(H_2O)]$ (3), layer $[Mn(H_2bptc)(H_2O)]_n$ (4) and a dinuclear compound $[Ni_2(H_2bptc)-(H_2O)_2]{\cdot}6H_2O$ (5). These compounds have been characterized by elemental analysis, IR, and their structures have been determined by X-ray crystallography. The thermal stabilities of 1-3 were measured by thermogravimetric analysis (TGA) and their solid state luminescence properties together with the free ligand $H_4bptc$ were investigated at room temperature.

• 한국세라믹학회지
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• 제25권2호
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• pp.136-142
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• 1988

β-Al2O3, which is used for solid electrolyte membrances in sodium-sulfur batteries, was prepared by sol-gel process. Sodium-n-propoxide NaOC3H7 and aluminum-isopropoxide Al(OC3H7)3 were hydrolyzated in the solution at pH 3, pH 7, pH 9 and pH 11, respectively. The sol-gel processed samples were calcined at several temperature steps, respectively and analysed by thermal analyser(DT-TGA), infrared spectrum analyser and X-ray diffraction analyser. The gelling rate of solution at pH 7 was much higher than that of the solution at pH 3. Thermal exchanging behavior of the gels at pH 3 were similar to Na2O·Al2O3·6H2O and, above pH 7, were similar to Na2O·Al2O3·3H2O. When samples' composition ratio was 9.13 : 90.87 [NaOC3H7:Al(OC3H7)3] at pH 7, β-Al2O3 was formed at 1100℃.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.1
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• pp.382-385
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• 2003

Chemical mechanical polishing(CMP) is an essential process in the production of copper-based chips. On this work, the stability of Hydrogen Peroxide($H_2O_2$) as oxidizer of Cu CMP slurry has been investigated. $H_2O_2$ is known as the most common oxidizer in Cu CMP slurry. Copper slowly dissolves in $H_2O_2$ solutions and the interaction of $H_2O_2$ with copper surface had been studied in the literature. Because hydrogen peroxide is a weak acid in aqueous solutions, a passivation-type slurry chemistry could be achieved only with pH buffered solution.[1] Moreover, $H_2O_2$ is so unstable that its stabilization is needed using as oxidizer. As adding KOH as pH buffering agent, stability of $H_2O_2$ decreased. However, stability went up with putting in small amount of BTA as film forming agent. There was no difference of $H_2O_2$ stability between KOH and TMAH at same pH. On the other hand, $H_2O_2$ dispersion of TMAH is lower than that of KOH. Furthermore, adding $H_2O_2$ in slurry in advance of bead milling lead to better stability than adding after bead milling. Generally, various solutions of phosphoric acids result in a higher stability. Using Alumina C as abrasive was good at stabilizing for $H_2O_2$; moreover, better stability was gotten by adding $H_3PO_4$.

• Environmental Engineering Research
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• 제16권3호
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• pp.131-136
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• 2011

The degradation of 30 pharmaceuticals and personal care products (PPCPs) subjected to $O_3$, $O_3$/UV, and $O_3/H_2O_2$ treatments were investigated using semi-batch tests and evaluated by their pseudo-first-order rate constants. The additional application of UV or $H_2O_2$ during $O_3$ treatment significantly improved the degradation rate of most of the PPCPs. At the same $O_3$ feed rate, $O_3$/UV treatment exhibited much higher PPCP degradation efficiency than that of $O_3$ treatment. This was probably due to degradation of the PPCPs by $O_3$, direct UV photodegradation, and OH radicals that formed from the photodegradation of $O_3$ during $O_3$/UV treatment. PPCP degradation by $O_3$ was also promoted by adding $H_2O_2$ during the $O_3$ treatment. However, when the initial $H_2O_2$ concentration was high during $O_3$ treatment, OH radicals were likely to be scavenged by excess $H_2O_2$, leading to low PPCP degradation. Therefore, it is important to determine the appropriate $H_2O_2$ dosage during $O_3$ treatment to improve PPCP degradation when adding $H_2O_2$ during $O_3$ treatment.

• Bulletin of the Korean Chemical Society
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• 제7권5호
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• pp.338-341
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• 1986

Hydrocarbon solution of $Ir(PPh_3)_2(CO)OClO_3$ reacts with $Ph_2PC_6H_4$-o-CHO and 3-methyl-2-aminopyridinyl aldimine to yield ${\bar{Ir(Ph_2PC_6H_4-o-CO)}}\;(PPh_3)_2(CO)(H)ClO_4$(1) and ${\bar{Ir(NC_6H_6NC}}C_6H_5)(PPh_3)_2(CO)(H)ClO_4$(2), respectively. The compound $Ir(PPh_3)_2N_2Cl$ also reacts with $Ph_2PC_6H_4$-o-CHO and 3-methyl-2-aminopyridinyl aldimine to give ${\bar{Ir(Ph_2PC_6H_4-o-C}}O)(PPh_3)_2(H)Cl(3)$ and $Ir(NC_6H_5NCC_6H_5(PPh_3)_2(H)Cl(4)$, respectively. Compounds 1, 2, 3, and 4 were characterized by infrared, $^1H$ NMR, $^{31}p$ NMR, UV spectra, and conductivity measurements.

• 대한화학회지
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• 제15권6호
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• pp.312-317
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• 1971

아닐린, o-톨루이딘, o-에틸아닐린, o-클로로아닐린등과 $I_2$사이의 상호작용을 자외선 분광광도법으로 조사한 결과 $CCl_4$ 용액내에서 아닐린 또는 상기 o-치환 아닐린과 $I_2$ 사이에 1:1 착물이 형성됨을알았다. 이들 착물의 실온에서의 형성상수를 구한 결과 다음과 같은값을 얻었다. $C_6H_5NH_2{\cdot}I_2,\;12.8lmole^{-1};\;o-CH_3C_6H_4NH_2{\cdot}I_2,\;9.31l mole^{-1};\;o-C_2H_5C_6H_4NH_2{\cdot}I_2,\;3.15l mole^{-1};\;o-ClC_6H_4NH_2{\cdot}I_2,\;0.576 l mole^{-1}$. 본 실험결과를 전 실험의 결과와 비교하면 $I_2{\cdot}$아민 착물의 안정도가 다음 순으로 감소함을 알 수 있다. $C_6H_5N(C_2H_5)_2 >C_6H_5N(CH_3)_2 >C_6H_5NH_2 >o-CH_3C_6H_4NH_2 >o-C_2H_5C_6H_4NH_2 >o-ClC_6H_4NH_2$ 이들 착물의 상대적 안정도는 치환기의 유발효과와 입체효과에 의하여 설명될 수 있다.

• 한국세라믹학회지
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• 제31권10호
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• pp.1231-1239
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• 1994

In this study, gel powder which had relatively high hydration reactivity in CaO and P2O5 rich composition of CaO-P2O5-SiO2-H2O system was prepared by sol-gel process and its hydrated specimen was manufactured. The it was investigated to appropriate calcination temperature in sol-gel process which hydrated specimen of gel powder have proven to strength and the effect of factors influenced strength in hydration process. The major product of before and after hydration reaction was hydroxyapatite, and crystalline phase of C-S-H was already formed during gelation process. After hydration reaction of pressed specimen, crystalline phase of C-S-P-H was formed. It was hydrated product of silicocarnotite (5CaO.P2O5.SiO2). Gel phases of C-S-H and C-S-P-H occured as a result of partial substitution of amorphous silica by P2O5 was formed. The strength of hydrated hardened body is developed by strong bonding and bridging between the gel phases of C-S-H or C-S-P-H and the crystalline products such as hydroxyapatite, Ca(OH)2 C-S-H and C-S-P-H. In addition, the ultrafine gel powder have an great effect on increase of hydration reaction.

• 공업화학
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• 제16권1호
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• pp.45-51
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• 2005

Aluminum nitrate 수용액을 원료로 사용하여 $K_2O-Li_2O-Al_2O_3$ 3성분계로부터 $K^+-{\beta}^{{\prime}{\prime}}-Al_2O_3$를 합성하였다. 순수한 $K^+-{\beta}^{{\prime}{\prime}}-Al_2O_3$의 합성을 위하여 원료물질은 $0.84K_2O{\cdot}0.082Li_2O{\cdot}5.2Al_2O_3$의 조성으로 액상상태에서 혼합되었다. 입자크기를 최소화하고 순수한 $K^+-{\beta}^{{\prime}{\prime}}-Al_2O_3$를 합성하는데 있어서 분산첨가제와 용액의 pH의 영향을 조사하였다. 분산첨가제로써 에탄올을 0.0~4.0 M 첨가하였고 용액의 pH는 $NH_4OH$ 수용액과 $HNO_3$를 이용하여 조절하였다. 시료는 pH 1.0에서 7.5까지 0.5 간격으로 수집하였다. 각 시료들은 $1200^{\circ}C$에서 2 h 동안 하소한 후 XRD와 PSA 분석을 하였다. 용액의 pH는 입자크기와 상형성에 모두 중요한 영향을 미친 반면, 에탄올의 첨가는 입자크기에만 영향을 주었다. pH 조절에 $HNO_3$를 사용하였을 경우, $HNO_3$를 사용하지 않았을 때 보다 순수한 $K^+-{\beta}^{{\prime}{\prime}}-Al_2O_3$ 상을 합성하는데 유리함을 알 수 있었다.

• 공업화학
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• 제7권4호
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• pp.645-652
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• 1996

본 연구는 $H_2S$를 $TiO_2/SiO_2$ 촉매상에서 산소와의 직접 산화 반응을 통해 원소 황의 형태로 제거하는 반응에 관한 것이다. 순수한 $TiS_2$와 $Ti(SO_4)_2$를 사용한 반응 실험과 순수한 $TiO_2$에 대한 주기적 온도 조작 실험 결과로부터 $TiO_2$는 황 회수 공정에서 사용되는 촉매의 비활성화의 주원인으로 알려진 sulfation이나 sulfidation에 대해 매우 안정한 것으로 나타났다. $TiO_2/SiO_2$촉매에서 $TiO_2$의 담지랑이 증가함에 따라 $H_2S$의 전화율이 증가하였고, 원소 황의 선택도는 아주 소폭으로 감소하였다. 반응 실험 결과 $O_2/H_2S$의 비가 증가할수록 원소 황의 선택도는 크게 감소하였다. 10 wt.% $TiO_2/SiO_2$ 촉매는 화학 양론비의 조성($H_2S$=5 vol.% $O_2$=2.5 vol.%)의 반응물에 10 vol.%의 수증기를 첨가한 경우 활성과 선택도가 감소하였으나 여전히 80% 이상의 원소 황 수율을 유지하고 있었다.

• 상하수도학회지
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• 제18권3호
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• pp.377-384
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• 2004

In the present study, a feasibility of an advanced oxidation process using UV/Hydrogen peroxide($H_2O_2$) system equipped with a medium pressure lamp for secondary effluent reclamation was investigated. Initial concentration of $H_2O_2$ and pH were changed to determine the optimum operation condition for the system. The removal efficiency of color was than 80% with 14.3mg/L of initial $H_2O_2$ and 5 minute of contact time in the UV/$H_2O_2$ system. The color removal was analyzed using first-order reaction equation. The dependence of rate constant (k) on initial $H_2O_2$ represented the rational relationship with maximum value. Residual $H_2O_2$ caused increase of effluent COD, since analyzing agent, dichromate, reacted with $H_2O_2$ in the sample. Therefore, excess initial concentration of $H_2O_2$ would significantly affect effluent COD measurement. At pH variation experiment, both residual $H_2O_2$ and color showed peak in the neutral pH range with the same pattern. Effect of $H_2O_2$ dose also enhanced color removal but raised residual $H_2O_2$ problem in the continuous operation UV system. In conclusion, these results indicated that medium pressure UV/$H_2O_2$ system could be used to control color in the secondary effluent for reclamation and reuse.