ZnO particles are successfully synthesized at 150 oC for 30 min using zinc acetate as the Zn source and 1,4- butanediol as solvent using a relatively facile and convenient glycol process. The effect of ammonium hydroxide amounts on the growth behavior and the morphological evolution of ZnO particles are investigated. The prepared ZnO nanoparticle with hexagonal structure exhibits a quasi-spherical shape with an average crystallite size of approximately 30 nm. It is also demonstrated that the morphology of ZnO particles can be controlled by 1,4-butanediol with an additive of ammonium hydroxide. The morphologies of ZnO particles are changed sequentially from a quasi-spherical shape to a rod-like shape and a hexagonal rod shape with a truncated pyramidal tip, exhibiting preferential growth along the [001] direction with increasing ammonium hydroxide amounts. It is demonstrated that much higher OH− amounts can produce a nano-tip shape grown along the [001] direction at the corners and center of the (001) top polar plane, and a flat hexagonal symmetry shape of the bottom polar plane on ZnO hexagonal prisms. The results indicate that the presence of NH4+ and OH− ions in the solution greatly affects the growth behaviors of ZnO particles. A sharp near-band-edge (NBE) emission peak centered at 383 nm in the UV region and a weak broad peak in the visible region between 450 nm and 700 nm are shown in the PL spectra of the ZnO synthesized using the glycol process, regardless of adding ammonium hydroxide. Although the broad peak of the deep-level-emission (DLE) increases with the addition of ammonium hydroxide, it is suggested that the prominent NBE emission peaks indicate that ZnO nanoparticles with good crystallization are obtained under these conditions.

본 논문에서는 피혁에 사용되는 수용성 폴리우레탄 사슬 연장제인 1,4-butanediol(1,4-BD)의 함유에 따른 물성변화를 조사하였다. 합성에 사용된 시약은 poly propylene glycol(PPG), isoporon diisocyanate((IPDI), dimethylolpropionic acid(DMPA), 1,4-BD를 사용하였다. 1,4-BD의 함유에 따른 내용제성과 내굴곡성 측정값은 시료 전부 우수한 물성을 보였다. 인장강도, 내마모성 측정결과 1,4-BD가 많이 함유된 시료들이 각각 1.80kgf/mm2, 49.54 mg.loss로 우수한 물성을 확인하였다. 연실율 측정결과 1,4-BD가 적게 함유된 시료가 364%로 가장 우수한 측정값을 나타냈다.

목 적: 1,4-Butanediol 과 (±)-1,2,4-butanetriol 은 안구 내 사용되는 콘택트렌즈의 습윤성을 향상시킨다. 본 실험은 하이드로젤 콘택트렌즈에 1,4-butanediol과 (±)-1,2,4-butanetriol이 미치는 물리적 특성을 제조된 콘택트렌즈의 함수율과 접촉각을 측정하여 각각 비교하였다. 방 법 : 하이드로젤 렌즈의 주재료인 HEMA(2-hydroxyethyl methacrylate)에 ethylene glycol dimethacrylate(EGDMA)를 첨가한 조합을 기본 배합으로 하여 MMA(methyl methacrylate) 1%, AA(acrylic acid) 5%를 각각 배합하여 공중합한 조합으로 콘택트렌즈를 제조하였다. 기본조합 렌즈의 물성을 측정한 후 1,4-butanediol과 (±)-1,2,4-butanetriol을 1∼10% 첨가하여 공중합한 렌즈를 24시간 수화시킨 후 렌즈의 기본 물성을 측정하였다. 대표적으로 굴절률, 광투과율, 함수율, 접촉각, 인장강도 등을 측정하였다. 결 과 : HEMA, MMA, AA의 기본 조합에 1,4-butanediol과 (±)-1,2,4-butanetriol의 양을 점차적으로 증가시켜 측정한 두 조합의 평균 함수율은 37.18~37.67%의 범위로 측정되었으며, 굴절률은 1.4319~1.4328의 범위로 나타났다. 또한 가시광선 투과율은 모든 조합에서 89.6% 이상의 투과율을 나타내었으나 자외선 차단성은 없는 것으로 나타났다. 또한 첨가량에 따른 접촉각은 57.59°에서 38.28°로 감소하였으며, 인장강도는 0.2570 kgf에서 0.1677 kgf로 감소하였다. 결 론 : 친수성 물질인 1,4-butanediol과 (±)-1,2,4-butanetriol은 하이드로젤 렌즈의 기본적인 물리적 특성을 충족시키면서도 우수한 습윤성을 갖는 것으로 나타났다.

Esterification reaction between succinic acid[SA] and 1,4-butanediol [BD] was kinetically investigated in the presence of organometallic catalysts (ESCAT-100Ag18, MBTO) at 150~180℃. The reaction followed from the measurement of the quantity of water which was distilled from the reaction vessel. The esterification reaction was carried out under the first order kinetics with respect to the concentration of reactants and catalyst, respectively. The overall reaction order was 2nd. From the examination of relationship between apparent reaction rate constants and reciprocal absolute temperature, the activation energy has been calculated as 146.70 kJ/mol(ESCAT-100Ag18) and 87.57 kJ/mol(MBTO), respectively.

Esterification reaction between succinic acid and 1,4-butanediol was kinetically investigated in the presence of nontoxic organometallic compound catalyst(ESCAT-100E) at 150-190℃. The reaction rates measured by the amount of distilled water from the reaction vessel. The Esterification reaction was carried out under the first order conditions respect to the concentration of reactants, respectively. The overall reaction order was 2nd. The linear relationship was shown between apparent reaction rate constant and reciprocal absolute temperature. By the Arrhenius plot the activation energy have been calculated as 376.13 kJ/mol under nontoxic organometallic compound catalyst and also apparent reaction rate constant, k' was found to obey first kinetics with respect to the concentration of catalyst.

Esterification reaction between succinic acid[SA] and 1,4-butanediol [BD was kinetically investigated in the presence of organic metal catalysts (alkyl-silver oxide(ASO),CAT 100E) at 150~190℃. The reaction rates measured by the amount of distilled water from the reaction vessel. The esterification reaction was carried out under the first order kinetics with respect to the concentration of reactants and catalyst, respectively. The overall reaction order was 2nd. From the examination of relationship between apparent reaction rate constants and reciprocal absolute temperature, the activation energy has been calculate as 146.70 kJ/mol with ASO catalyst and 43.04 kJ/mol with CAT 100E catalyst.

Esterification reaction between succinic acid and 1,4-butanediol was kinetically investigated in the presence of monobutyl tinoxide catalysts at 150~190℃. The reaction rates measured by the amount of distilled water from the reaction vessel. The esterification reaction was carried out under the first order conditions with respect to the concentration of reactants, respectively. The overall reaction order was 2nd. The linear relationship was shown between apparent reaction rate constant and reciprocal absolute temperature. By the Arrhenius plot the activation energy have been calculated as 87.567 kJ/mol under monobutyl tinoxide catalyst and also apparent reaction rate constant, k' was found to obey first kinetics with respect to the concentration of catalyst.

In this study, 3 mol% yttria-tetragonal zirconia polycrystal (3Y-TZP) nanoparticles were synthesized by the glycothermal method under various reaction temperatures and times. The co-precipitated precursor of 3Y-TZP was prepared by adding NH4OH to starting solutions, and then the mixtures were placed in an autoclave reactor. Tetragonal yttria-doped zirconia nanoparticles were afforded through a glycothermal reaction at a temperature as low as 220˚C, using co-precipitated gels of ZrCl4 and YCl3·6H2O as precursors and 1,4-butanediol as the solvent. The synthesized 3Y-TZP particles were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and Raman spectroscopy. The 3Y-TZP particles have a stable tetragonal phase only at glycothermal temperatures above 200˚C. To investigate phase transition, the 3Y-TZP particles were heat treated from 400 to 1400˚C for 2 h. Raman analysis indicated that, after heat treatment, the tetragonal phase of the 3Y-TZP particles remained stable. The results of this study, therefore, suggest that 3Y-TZP powders can be prepared by the glycothermal method.

The transesterification of dimethylphthalate by 1,4-butanediol was kinetically investigated In the presence of various metal acetate catalysts at 180℃. The quantity of dimethylphthalate reacted in the reaction flask was measured by gas chromatography. The transesterification was assumed to obey first-order kinetics with respect to dimethylphthalate and 1,4-butanediol, and a rate equation was derived. The linear relationship was shown between apparent rate constant and reciprocal absolute temperature, the activation energy has been calculated as 7.4kcal with lead acetate. The maximum reaction rate was appeared at the range of 1.5~1.6 of electronegativity of metal ions.