• Bulletin of the Korean Chemical Society
• /
• 제26권2호
• /
• pp.265-267
• /
• 2005

An efficient method of addition of trimethylsilyl cyanide to aldehydes by employing a zirconium complex as the catalyst has been described. A variety of aromatic, aliphatic, cyclic and heterocyclic aldehydes has been converted into corresponding trimethylsilyl ethers in excellent yield within short reaction time.

• 대한화학회지
• /
• 제54권3호
• /
• pp.283-286
• /
• 2010

지르코늄의 부유-분광 광도의 측정에 대한 감도가 좋고 재현성 있는 방법이 기록되었다. 그 방법은 지르코늄과 자일렌오렌지(XO)착물 형성에 기초하였고 그것은 격렬한 진탕에 의해 수용액 상과 n-헥산의 표면에 떠있게 된다. 수용액과 n-헥산을 폐기함에 따라 분리된 깔대기의 벽에 있던 흡착된 착물은 작은 부피의 메탄올 용액으로 해리되어진다. 그리고 그것의 흡광도는 429 nm에서 측정되었다. PH, HCl, XO의 농도, n-헥산 부유 용매의 부피, 지속시간과 진탕시간과 같은 다른 변수의 효과가 연구되었다. 보정곡선은 0.9991의 상관계수를 갖는 지르코늄의 7 ~ 120 ng/mL의 범위에서 선형이었다. 검출한계(LOD)는 58 ng/mL이었다. 지르코늄의 50과 110 ng/mL 의 7개의 분할척정에 대한 상대표준편차(RSD)는 4.4와 3.0%였다. 이 방법은 물샘플에서 지르코늄의 측정에 성공적으로 적용되었다.

• Bulletin of the Korean Chemical Society
• /
• 제26권5호
• /
• pp.852-854
• /
• 2005

• Journal of Pharmaceutical Investigation
• /
• 제18권3호
• /
• pp.107-111
• /
• 1988

Zr, Cu, Zn and Fe-pyrithione complexes were prepared in aqueous medium and their antimicrobial activities were evaluated by MIC and cylinder plate methods against Bacillus subtilis, Sarcina lutea, Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumoniae, Trichophyton mentagrophytes, Candida albicans, Asperillus niger and Saccharomyces cerevisiae. Zr-pyrithione possessed most potent activities among the metal complexes against a wide range of microorganisms, especially Gram positive, B. subtilis, S. aureus and fungus, C. albicans. And all of the metal complexes synthesized were more active than pyrithione base. Fe(III)-pyrithione complex has an equal potency to Zn-pyrithione in general but it showed potent activity against B. subtilis microorganism than Zn-pyrithione.

• 상하수도학회지
• /
• 제19권4호
• /
• pp.455-461
• /
• 2005

This study was designed to investigate the fundamental aspects of a possible recovery of phosphorus strategy from wastewater by using the zirconium mesoporous structured materials as a new type of ion exchangers. Zirconium mesoporous structure material was synthesized by hydro-thermal synthesis. The synthesized zirconium mesoporous structure was examined by X-ray diffraction (XRD) and Transmission electron micrograph (TEM). From the results of XRD and TEM, it was found out that hexagonal mesoporous structure, pore size was about $47{\AA}$, was synthesized. Experimental results showed that the complex of zirconium sulfate tetrahydrate and surfactant micelles had very high ability for capture of phosphorus. The amount of phosphate ions exchanged into the solid was as great as 3.4mmol/g-ZS. And the ion exchange reaction was occurred between $PO_4{^{3-}}$ and $SO_4{^{2-}}$ and also between $PO_4{^{3-}}$ and $OH^-$. Therefore, it is possible to get the higher removal efficiency than other ion exchange media and adsorbent.

• Bulletin of the Korean Chemical Society
• /
• 제28권7호
• /
• pp.1127-1134
• /
• 2007

It was demonstrated that Y[N(TMS)2]3, the neutral yttrium-diamine complex 13 and yttrium-NPS complexes 15 are efficient precatalysts for intramolecular hydroamination of aminoalkynes involving primary amines. Complex 13 and 15 were quantitatively prepared in situ by direct metalation of the ligands 4 and 9 with 1 equiv of Y[N(TMS)2]3 in benzene-d6 at 120 oC for 5 days and 10 days, respectively, via elimination of (TMS)2NH. 5-Exo- and 6-exo-dig intramolecular hydroamination of aminoalkynes using catalyst 12 and 13 proceeded smoothly to give nitrogen-contained cyclic products in good to excellent yields in all cases. In the case of 7- exo-dig intramolecular hydroamination, the desired product was produced in 41% and 48% yields despite the gem-dimethyl effect. However, treatment of catalyst 15 with aminoalkynes (19 and 22) having a methyl substituent at the carbon adjacent to triple bond and 6-exo-dig intramolecular hydroamination of 21 failed to give the desired products. Zirconium-catalyzed intramolecular hydroamination of aminoallenes (25, 27, and 31) with 5 mol% 16 afforded 2-(trans-1-propenyl)pyrrolidine, 2-isopropylenepyrrolidine, and 2-(trans-1- propenyl)piperidine in 96%, 95%, and 93% yield, respectively. However, subjecting 25 to 5 mol% 15 was unsuccessful to produce the desired product.

• Bulletin of the Korean Chemical Society
• /
• 제30권2호
• /
• pp.479-481
• /
• 2009

• 공업화학
• /
• 제23권1호
• /
• pp.8-13
• /
• 2012

본 연구에서는 프린터 토너의 대전량 제어제로 사용되는 아연 착화합물 제조시 금속염과 다가알코올을 첨가함에 따라 변화되는 입자 형태와 평균 입도에 대해 고찰하였다. 아연 착화합물을 제조하기 위해 염화아연과 3,5-di-tert-butyl salicylic acid를 사용하였다. 다가알코올을 첨가함에 따른 입자형태 변화를 확인하기 위해 아연 착화합물 제조시 polyethylene glycol (PEG-300), glycerin 및 ethylene glycol을 첨가하였고, 금속염인 지르코늄 옥시클로라이드를 첨가함으로써 변화되는 입자크기를 확인하였다. 또한 금속염과 다가알코올을 동시에 첨가하여 입도변화를 확인한 결과, 각각 단독으로 첨가했을 때보다 아연 착화합물의 평균 입도가 더 많이 감소하는 것을 확인할 수 있었다. 특히, 지르코늄 착화합물의 함유량이 30 wt%이고 염화아연에 대한 PEG-300의 몰비를 3으로 하였을 때 아연 착화합물의 평균 입도가 1.84 ${\mu}m$로 순수한 아연 착화합물의 평균 입도(5.28 ${\mu}m$)의 34.9%로 가장 많이 감소한 것을 알 수 있었다.

• 한국압력기기공학회 논문집
• /
• 제13권2호
• /
• pp.75-83
• /
• 2017

In severe accident conditions of light water reactors, the loss of coolant may cause problems in integrity of zirconium fuel cladding. Under the condition of the loss of coolant, the zirconium fuel cladding can be exposed to high temperature steam and reacted with them by producing of hydrogen, which is caused by the failure in oxidation resistance of zirconium cladding materials during the loss of coolant accident scenarios. In order to avoid these problems, we develop a multi-metallic layered composite (MMLC) fuel cladding which compromises between the neutronic advantages of zirconium-based alloys and the accident-tolerance of non-zirconium-based metallic materials. Cold pilgering process is a common tube manufacturing process, which is complex material forming operation in highly non-steady state, where the materials undergo a long series of deformation resulting in both diameter and thickness reduction. During the cold pilgering process, MMLC claddings need to reduce the outside diameter and wall thickness. However, multi-layers of the tube are expected to occur different deformation processes because each layer has different mechanical properties. To improve the utilization of the pilgering process, 3-dimensional computational analyses have been made using a finite element modeling technique. We also analyze the dimensional change, strain and stress distribution at MMLC tube by considering the behavior of rolls such as stroke rate and feed rate.

• Journal of Pharmaceutical Investigation
• /
• 제20권3호
• /
• pp.145-152
• /
• 1990

Zirconium pyrithione complex was prepared by reaction of sodium-pyrithione solution and zirconyl chloride solution. The physico-chemical properties of the complex was examined by means of IR, XRD, DSC and NMR. And the stability of Zr-complex was investigated on the basis of accelerated stability analysis under conditions of temp. elevation, UV radiation and pH dependence. The result indicates that the ratio of the ligand to metal in Zr-pyrithione complex was determined 4:1, and its stability constant was $4.643{\times}10^4$. The rate order of decomposition of the complex was apparent first-order reaction of which rate constant and the decomposition rate was not only accelerated by effect of heat and UV radiation but was catalyzed by specific acid-base catalysis considered the pH dependence for the hydrolysis of the complex and the suspension was most stable over the range pH 4-8 indicating that solvent catalysis is the primary made of reaction in this region.