• Fibers and Polymers
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• 제3권1호
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• pp.1-7
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• 2002

Cellulose carbonate was prepared by the reaction of cellulose pulp and $CO_2$ with treatment reagents, such as aqueous $Zncl_2$ (20-40 wt%) solution, acetone or ethyl acetate, at -5-$0^{\circ}C$ and 30-40 bar ($CO_2$) for 2 hr. Among the treatment reagents, ethyl acetate was the most effective. Cellulose carbonate was dissolved in 10% sodium hydroxide solution containing zinc oxide up to 3 wt% at -5-$0^{\circ}C$. Intrinsic viscosities of raw cellulose and cellulose carbonate were measured with an Ubbelohde viscometer using 0.5 M cupriethylenediamine hydroxide (cuen) as a solvent at $20^{\circ}C$ according to ASTM D1795 method. The molecular weight of cellulose was rarely changed by carbonation. Solubility of cellulose carbonate was tested by optical microscopic observation, UV absorbance and viscosity measurement. Phase diagram of cellulose carbonate was obtained by combining the results of solubility evaluation. Maximum concentration of cellulose carbonate for soluble zone was increased with increasing zinc oxide content. Cellulose carbonate solution in good soluble zone was transparent and showed the lowest absorbance and the highest viscosity. The cellulose carbonate and its solution were stable in refrigerator (-$5^{\circ}C$ and atmospheric pressure).

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1999년도 하계종합학술대회 논문집
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• pp.283-286
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• 1999

Transparent conductive aluminum-doped ZnO(AZO) films Were prepared by a ultrasonic spray pyrolysis method at the substrate temperature below 23$0^{\circ}C$. A vertical type hot wall furnace was used as a reactor in the deposition system. Zinc acetate dissolved in methanol was selected as a precursor. The substrate temperature was varied from 18$0^{\circ}C$to 24$0^{\circ}C$. Aluminum (Al) was doped into ZnO films by incorporating anhydrous aluminum chloride (AlCl$_3$) in the zinc acetate solution. The proportion of the Al in the starting solution was varied from 0 wt % to 3.0 wt %. The crystallographic properties and surface morphologies of the films were analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. The resistivity of the films was measured by the Van der Pauw method, and the mobility and carrier concentration were obtained through the Hall effect measurements Transmittance was measured in the visible region. The effects of substrate temperature and aluminum content in the starling solution on the structural and electrical properties of the AZO films are discussed

• 공업화학
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• 제28권6호
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• pp.645-648
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• 2017

전량 수입에 의존하고 있는 ABS 수지의 내열성 강화를 위한 화합물인 N-phenylamleimide (PMI)의 상업화를 위한 촉매개발을 완료하였다. Maleic anhydride와 aniline과 반응을 통하여 중간체인 N-phenylmaleamic acid (PMA)를 정량적으로 얻은 후, PMI를 얻기 위한 촉매를 탐색하였다. Zinc acetate/$Et_3N$의 복합 촉매가 단일 산 촉매보다 우수한 성능을 보임을 확인하였다. 개발된 복합 촉매를 사용하여 추가 정제 공정 없이 90% 수율과 99.3%의 순도로 PMI를 합성할 수 있었다.

• Korean Chemical Engineering Research
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• 제56권1호
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• pp.103-111
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• 2018

본 연구에서는 PET (Poly Ethylene Terephthalate)의 단량체인 BHET (bis (2-Hydroxyethyl) Terephthalate)와 1,4-BD(1,4-Butanediol)의에스테르교환반응을활용하여 PBT (Poly Butylene Terephthalate)의단량체인 BHBT (Bis (4-Hydroxybutyl Terephthate)를 생성하는 반응에 대하여 조사하였다. 이 반응의 촉매로 Zinc Acetate를 사용하였다. 회분식 반응기를 통하여 BHET, EG (Ethylene Glycol), THF (Tetrahydrofuran)의 양을 정량하여 반응 kinetics 모델을 구성하였다. 제시된 모델을 통하여 반응속도와 반응물의 조성 분포를 조사하였고, 이 모델의 예측 값과 실험 값들이 잘 일치함을 보였다.

• 대한화학회지
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• 제60권1호
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• pp.34-38
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• 2016

본 연구는 zinc acetate dihydrate와 sodium hydroxide를 사용하여 ZnO nanoparticles (ZnO NPs)을 합성하였다. 실험에 사용된 방법은 초음파 방법이다. 같은 농도의 각각 zinc acetate dihydrate와 sodium hydroxide를 de-ionized water에 넣고 30분간 교반 하였다. 이 과정에서 생성된 백색의 생성물은 교반 하면서 ultrasonic processor을 사용하여 각각 60분, 120분, 180분, 240분, 360분 처리하였다. 생성물들은 원심분리 후 남은 이온들을 제거하기 위하여 에탄올을 사용하여 여러 번 세척하고, 50 ℃에서 24시간 동안 건조하였다. 합성된 물질들의 결정성과 구조적 특성을 확인하기 위하여 X-ray diffraction spectroscopy(XRD)와 Field emission scanning electron microscopy(FE-SEM)을 사용하였다. 광 촉매 효과는 오염물질 대신 Rhodamin-B를 사용하여 UV 조사하에 암실에서 실험하였다. 광 촉매 효과는 UV-vis spectrometer를 이용하여 확인하였다. XRD 결과 순수한 ZnO가 합성된 것을 확인 하였다. FE-SEM을 통하여 시간이 지남에 따라 구 형태에서 막대형태를 지나 꽃 형태로 변하는 것을 확인 할 수 있었다. 광촉매 특성 결과 꽃 형태를 가진 ZnO NPs가 광 촉매 특성이 가장 우수한 것으로 확인 되었다.

• 한국세라믹학회지
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• 제44권1호
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• pp.32-36
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• 2007

Zinc gallate $(ZnGa_2O_4)$ thin film phosphors have been formed on ITO glass substrates by a sol-gel spinning coating method. For the formation of the film phosphors, the starting materials of zinc acetate dihydrate, gallium nitrate hydrate and 2-methoxyethanol as a solution were used. The thin films deposited were firstly dried at $100^{\circ}C$ and fired at $500^{\circ}C\;or\;600^{\circ}C$ for 30 min and then, annealed $500^{\circ}C\;or\;600^{\circ}C$ at for 30 min under an annealing atmosphere of 3% $H_2/Ar$. The thin films deposited on ITO glass plates showed the (220), (222), (400), (422), (511), and (440) peaks of spinel structure as well as the (311) peak indicating a standard powder diffraction pattern. The surface morphologies of the thin film phosphors were observed with a firing and an annealing condition. The $ZnGa_2O_4$ film phosphors showed the blue emission spectra around 410 nm as well as the emission spectra in the UV region (360-380 nm).

• 한국전기전자재료학회논문지
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• 제30권7호
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• pp.432-436
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• 2017

IZO transistors with $Al_2O_3$ as gate dielectrics have been investigated. To improve permittivity in an ambient dielectric layer, we grew $Al_2O_3$ by atomic layer deposition directly onto the substrates. Then, we prepared IZO semiconductor solutions with 0.1 M indium nitrate hydrate [$In(NO_3)_3{\cdot}xH_2O$] and 0.1 M zinc acetate dehydrate [$Zn(CH_3COO)_2{\cdot}2H_2O$] as precursor solutions; the IZO solution made with a molar ratio of 7:3 was then prepared. It has been found that these oxide transistors exhibit low operating voltage, good turn-on voltage, and an average field-effect mobility of $0.90cm^2/Vs$ in ambient conditions. Studies of low-voltage driving of IZO transistors with atomic layer-deposited high-k $Al_2O_3$ as gate dielectric provide data of relevance for the potential use of these materials and this technology in transparent display devices and displays.

• 한국전기전자재료학회논문지
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• 제30권7호
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• pp.437-440
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• 2017

We report on amorphous thin-film transistors (TFTs) with indium zinc oxide (IZO) channel layers that were fabricated via a solution process. We prepared the IZO semiconductor solution with 0.1 M indium nitrate hydrate and 0.1 M zinc acetate dehydrate as precursor solutions. The solution- processed IZO TFTs showed good performance: a field-effect mobility of $7.29cm^2/Vs$, a threshold voltage of 4.66 V, a subthreshold slope of 0.48 V/dec, and a current on-to-off ratio of $1.62{\times}10^5$. To investigate the static response of our solution-processed IZO TFTs, simple resistor load-type inverters were fabricated by connecting a $2-M{\Omega}$ resistor. Our IZOTFTbased N-MOS inverter performed well at operating voltage, and therefore, isa good candidate for advanced logic circuits and display backplane.

• 한국전기전자재료학회논문지
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• 제30권8호
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• pp.484-490
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• 2017

We investigated the rewritable operation of a non-volatile memory device composed of Al (top)/$TiO_2$/indium-zinc-oxide (IZO)/Al (bottom). The oxygen-deficient IZO layer of the device was spin-coated with 0.1 M indium nitrate hydrate and 0.1 M zinc acetate dehydrate as precursor solutions, and the $TiO_2$ layer was fabricated by atomic layer deposition. The oxygen vacancies IZO layer of an active component annealed at $400^{\circ}C$ using thermal annealing and it was proven to be in oxygen vacancies and oxygen binding environments with OH species and heavy metal ions investigated by X-ray photoelectron spectroscopy. The device, which operates at low voltages (less than 3.5 V), exhibits non-volatile memory behavior consistent with resistive-switching properties and an ON/OFF ratio of approximately $3.6{\times}10^3$ at 2.5 V.

• 센서학회지
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• 제6권2호
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• pp.155-162
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• 1997

zinc acetate를 포함하는 용액으로부터 r-plane 사파이어 기판 위에 ZnO 막(膜)을 증착하였다. 초음파(超音波) 발생기(發生器)로 용액을 진동시켜 증기입자를 만든 후 이것을 고온 반응로(反應盧) 내에서 열분해(熱分解) 시켜 막(膜)을 증착하였다. 제조된 막(膜)의 결정성, 표면형태 및 조성을 XRD, SEM 및 AES로 각각 분석하였다. 기판온도가 막(膜)의 특성에 미치는 영향에 대해 조사하였다. 기판온도 $300^{\circ}C$에서 (110) 방향으로 강하게 성장된 막(膜)을 얻을 수 있었다. 구리의 첨가(添加)와 습식산화(濕式酸化)에 의해 막(膜)의 저항율을 $3{\times}10^{6}{\Omega}{\cdot}cm$이상으로 높일 수 있었다.