nano cubes with high catalase activity were synthesized by reduction of freshly prepared Cu in distilled water at and their catalase activities of were studied. Transmission electron microscopy (TEM) observation showed that most of these nanocubes were uniform in size, with the average edge length of 30 nm. Selected area electron diffraction of TEM revealed that the nanocube consisted of single crystalline , but it changed to CuO phase. The catalase activity depends on the amount of both cuprite phase and surface area.

The results obtained are summarized as follows; (1) Boehmite produced in the high temperature and acid region showed a nano fibrous shape with several nm in diameter and several hundreds nm in length having high specific surface areas with a maximum value of . (2) In order to obtain nano fibrous boehmite with high surface areas from nano metal powder, the hydrolysis reaction should be done at a high temperature over , high acidity under pH 6, and terminated before a transition to the bayerite phase.

A formation of aluminum hydroxide by hydrolysis reaction in the water has been studied by using nano aluminum powder fabricated by pulsed wire evaporation(PWE) method. The hydroxide type and morphology depending on temperature and pH were examined by structural analysis. The Boehmite(. or AIO(OH)) was predominantly formed in high temperature region over 4, while the Bayerite(. or ) below of hydrolysis temperature. The Boehmite formation was preferred to the Bayerite in acidic solution in the same hydrolysis temperature. The slowly formed Bayerite phase showed facet crystalline structure, while the fast formed Boehmite was fine fiber with a large aspect ratio of several nm in diameter and several hundred nm in length, and with much larger specific surface area(SSA) than that of Bayerite. The highest SSA was about /g.

술폰화 폴리이미드는 클로로알칼리 전기분해, 양이온교환수지 및 연료전지용 고분자진해질막 등과 같은 많은 응용에 있어 유용한 재료로서 연구되어지고 있다. 그러나, 이러한 응용이 이루어지는 과정에 있어서 시간에 따라 연속적인 탈수공정이나 고분자의 분해에 따른 성능 감소 등이 보고되었다. 술폰화 고분자 분해의 주요 원인 중 하나로서 고분자 분자량의 감소 및 고분자 사슬의 절단으로 이끌어지는 가수분해를 들 수 있다. 따라서, 본 연구의 목적은 수화조건 하에서의 -SO3H와 연결된 이미드 사이클과 부가적인 에스테르 결합의 분해를 조사하는 데 있다. 사슬의 분리에 대해 가능한 정확한 정보를 얻고 이를 확인하기 위해서는 1H 및 13C NMR, FT-IR 분석을 이용했으며, 또한 보다 편리한 분석을 위해서 model compound를 사용하여 실험을 수행하였다. 결과적으로, 술폰화 폴리이미드의 수화안정성을 평가하기 위해서 프탈계 및 나프탈렌계 이미드 고리와 에스테르 결합을 갖는 model compound를 합성하였고, 제조된 model compound를 이용하여 80℃ 초순수 하에서 aging 실험을 수행하였고, lyophilization technique을 사용하여 반응을 중지시켰다. Aging된 product는 NMR, FT-IR spectroscopy를 이용하여 분석하였다.

The alkaline hydrolysis of alkyl alkylphosphinate and alkyl phenylphosphinates have been studied at room temperature. The hydrolysis proceeded as an one-stage reaction(SN 2) and involved a nucleophilic attack of the hydroxyl ion on the phosphorus atom. And the length of the alkoxy group in the phosphinate esters affected on hydrolysis. Therefore, the alkaline hydrolysis may be used as a method to decompose the chemical agents.

Phosphamidon의 가수분해속도상수는 25。C, pH 4, 7 및 9에서 각각 0.0020, 0.0022 및 0.0049이었고, 40。C에서 각각 0.0040, 0.0050및 0.0150으로 측정되었다 같은 pH에서 온도가 높을수록 촉진되었으며, pH 9의 염기성조건에서는 15。C상승에 반감기가 약 3배 정도 빨랐다. 또한 같은 온도에서 산성(pH 4)과 중성조건(pH 7)에 비해 염기성조건에서 가수분해반응이 약 2∼4배 정도 빨랐다. Profenofos의 가수분해속도상수는 25。C, pH 4, 7 및 9에서 각각 0.0022, 0.0047 및 0.0860이었고, 40。C에서 각각 0.0031, 0.0086 및 0.1245로 측정되었다. Profenofos의 가수분해는 phosphamidon과 마찬가지로 같은 pH에서 온도가 높을수록 촉진되었으며, 같은 온도에서 산성과 중성조건에 비해 염기성조건에서 가수분해반응이 약 15∼40배 정도 빨랐고 반감기가 모두 8시간 이내로 가수분해반응이 현저하게 일어났다. Profenofos의 가수분해속도가 phosphamidon보다 빠른 것을 알 수 있었다. 가수분해에 의한 분해산물을 확인하고자 GC/MS분석을 한 결과 phosphamidon의 분해생성물은 m/z=153의 O, O-dimethyl phosphate(DMP)와 m/z=149의 N, N-diethylchloro acetamide로 추정된다. Profenofos의 분해생성물은 m/z=208로 4-bromo 2-chloro phenol과 m/z=240으로 O-ethyl S-propyl phosphate로 추정된다.

불용성 농축어육단백질(fish protein concentration, FPC)의 기능성을 개선하기 위한 목적으로 한외여과막 반응기 (MWCO 5,000)를 사용하여 효소적 가수분해를 시도하였다. 막반응기에서 불용성인 FPC의 막힌현상(fooling)을 완화시키기 위하여 회분식에서 pepsin으로 1차 가수분해하였으며, 그 가수분해물을 한외여과막 반응기에서 pronase E를 사용하여 2차 가수분해하였다. 회분식에서 FPC의 최적가수분해 조건은 45℃, pH 2.0, 기질 대 효소비 150 (w/w)였으며, 이때의 가수분해도는 약 89%였다. 회분식에서 반응속도 상수 Km 및 Vmax는 각각 1.25%, 0.89 mg/mℓ/min이었으며, 기질농도 1.5% 이상에서 기질저해가 있었다. 한외여과막 반응기는 순환속도 474 mℓ/min, 투과압력 15 psi로 작동하였으며, 온도에 따른 투과유속은 증가하였으나 pH에 대해서는 거의 일정하였다. 막반응기에서 기질과 2차 가수분해효소 pronase E의 비 (S/E)는 200 (w/w)이 가장 효율적이었으며, 이때의 가수분해물의 생산량은 효소 mg당 702 mg으로 회분식 51 mg에 비해 13배 이상 높았다. FPC 가수분해물의 분자량은 1차 가수분해물의 경우 2,500~20,000 Da 영역에 분포하였으며, 2차 가수분해물은 700~10,000 Da 이었다.

2-phenyl-N-methyl-1,3-thiazolium perchlorate(PTP)derivatives were synthesized via addition and substitution reactions. PTP was hydrolyzed under aqueous hydrochloride. The structures of the compounds were conformed by N.M.R.,I.R., and elemental analysis.

The rate constants of hydrolysis of N-tert-butyl-α-phenylnitrone and its derivatives have been determined by UV spectrophotometry at 25℃ and a rate equation which can be applied over a wide pH range was obtained. On the basis of rate equations derived and judging from the hydrolysis products obtained and general base and substituent effects, plausible mechanism of hydrolysis in various pH range have been proposed. Below pH 4.5, the hydrolysis was initiated by the protonation and followed by the addition of water to α-carbon. Above pH 10.0, the hydrolysis was proceeded by the addition of hydroxides ion to α-carbon. In the range of 4.5~10.0 the addition of water to nitrone was rate controlling step.

화염가수분해증착법에 의해 형성된 0.1μm크기의 soot를 실리콘 기판위에 형성하여 1325˚C에서 2시간 동안 고밀화과정후 투명한 후막을 얻을 수 있었다. 고밀화 열처리는 탈수과정, 재배열 과정, 그리고 고밀화 과정으로 구성되었다. 고밀화 공정후의 두께 수축률은 초기 soot의 96%정도였으며, 급속한 두께의 감소는 950˚C부터 시작되었으며, 본격적인 고밀화가 시작되는 온도는 1250˚C임을 알 수 있었다. soot의 TGA와 DTA를 이용한 열분석 결과 탈수과정에 의하여 9/wt%의 질량감소와 1250˚C이상에서 인(P)의 증발에 의한 2wt%의 질량감소를 관찰하였다. DTA곡선에서는 500˚C, 570˚C. 1258˚C에서 흡열반응 피크를 나타내는데, 이는 B2O3, P2O5 등의 도펀트들의 melting과 실리카 입자사이의 기공이 소멸되면서 입자간의 열전도도의 증가에 의해 나타난 것으로 판단된다.

수직형 FHD증착법을 사용하여 SiO2, SiO2-P2O5, SiO2P2O5-B2O3-GeO2계 실리카 유리미립자를 형성하였으며, SEM, ICP-AES, XRD, TGA-DSC을 사용하여 그 특성을 분석하였다. XRD측정을 통해, 미립자 형성시 사용된 화염온도(1300˚C-1500˚C)와 기판온도(-200˚C)가 SiO2-P2O5계 미립자를 비정질상태로 형성하였으며, SiO2P2O5-B2O3와 SiO2P2O5-B2O3-GeO2계 미립자에서는 B2O3, BPO4, GeO2의 결정성피크들을 관찰하였다. TGA-DSC 열분석을 통해, SiO2와 SiO2-P2O5는 온도변화에 따른 질량변화가 없었으며, SiO2P2O5-B2O3-GeO2계의 경우 질량감소를 동반한 유리전이에 따른 분자이완현상 및 결정화나 회복반응을 나타내고 있다. 질량감소는 미립자가 결정상태일때 가속되는 경향을 나타냈으며, DSC열분석을 통해 SiO2, SiO2-P2O5, SiO2P2O5-B2O3-GeO2계 유리미립자들의 고밀화가 시작되는 온도를 각각 1224˚C, 1151˚C, 953˚C, 1130˚C에서 관찰하였다.

Furfurylidene acetophenone derivatives were synthesis, it was measured that hydrolysis made use of UV at a wide pH 1.0~13.0 range in 30% dioxane-H2O solution, 25±1℃. On the basis of general base catalysis, substitutent effect, confirmation of hydrolysis products, it was measured the reaction rate of furfurylidene acetophenone derivatives for the pH change. It maybe concluded that a part was unrelated to pH and another part was in proportion to concentration of hydroxide ion : Above pH 10.0, It was in proportion to concentration of hydroxide ion, a part having no concern with pH was added to the neutral H2O molecule. From the result of measurement the reaction rate, hydrolysis of furfurylidene acetophenone derivatives confirmed to the irreversible first order. Through measurement the substituent effect, It found that reaction rate was accelerated by electron attracting group. Also, From the result of final product, There were furfural and acetophenone. On the basis of these findings, Hydrolysis for the furfurylidene acetophenone derivative was proposed a fitting mechanisms.

The Kinetics velocity for hydrolysis reaction of vanillylidene imine derivatives has been measured by ultra-violet ray spectrophotometer in 20wt% dioxane-H2O at 25℃. It was measured the reaction rate Constant of vanillylidene imine derivatives that can be applied widely following to pH-change at 25℃. Final products that hydrolyzed the vanillylidene imine certified in vanillin and aniline derivative, and the effect of substitution radical that has affected on hydrolysis reaction was largely promoted to reaction rate by electron attrating group in acidity and electron donoring group in basic. From the results of rate constant to hydrolysis reaction, substituent radical effect and final products. It has certified the hydrolysis reaction mechanism of vanillylidene imine derivatives.

The Hydrolysis kinetics of Benzoyl Styrene Derivatives[I]~[IV] was investigated by ultraviolet spectrophotometery in 5% dioxane-H2O at 40℃. The structure of these compounds were ascertained by means of ultraviolet, melting point, IR and NMR spectra. The rate equations which were applied over a wide pH range (pH 1.0~13.0) were obtained. The substituent effects on Benzoyl styrene derivatives[I]~[IV] were studied, and the hydrolysis were facilitated by electron attracting groups. On the basis of the rate equation and substitutent effect and final product, the plausible hydrolysis reaction mechanism was proposed: At pH 1.0~pH 9.0, not relevant to the hydrogenl ion concentration, neutral H2O molecule competitively attacked on the double bond. By contrary. Above pH 9.0, It was proportional to concentration of hydroxidel ion.

The rate constants of hydrolysis of α-phenly-N-iso-propylnitrone and its derivatives have been determined by UV spectrophotometry at 25℃ and a rate equation which can be applied over a wide pH range was obtained. On the basis of rate equations derived and judging from the hydrolysis products obtained and general base and substituent effects, plausible mechanism of hydrolysis in various pH range have been proposed. Below pH 4.5, the hydrolysis was initiated by the protonation and followed by the addition of water to α-carbon. Above pH 10.0, the hydrolysis was proceeded by the addition of hydroxide ion to α-carbon. In the range of 4.5~10.0, the addition of water to nitrone was rate controlling step.

The hydrolysis reaction kinetics of 2-thienyl chalcone derivatives [II]~[V] was investigated by ultraviolet spectrophotometery in 20% dioxane-H2O at 25℃ and the structure of these compounds were ascertained by means of ultraviolet, infrared and NMR spectra. The rate equations which were applied over a wide pH range(pH 1.0~13.0) were obtained. The substituent effects on 2-thienyl chalcone derivatives[II]~[V] were studied, and the hydrolysis were facilitated by electron attracting groups. On the basis of the rate equation, substitutent effect and final product, the plausible hydrolysis reaction mechanism was proposed : At pH 1.0~9.0, not relevant to the hydrogen ion concentration, neutral H2O molecule competitvely attacked on the double bond. By contraries, above pH 9.0, it was proportional to concentration of hydroxide ion.