• Advances in nano research
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• 제14권2호
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• pp.201-210
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• 2023

A ZnO/poly (amide-imide) hybrid nanocomposite film with different weight percentages of Zinc oxide (ZnO) nanoparticles is synthesized and characterized in this paper. A two-step reaction successfully synthesized a new kind of heteroaromatic diamine with bulky pendant groups. In order to produce 3, 5-dinitro-3, 3-bis (4-(4-Nitrophenoxy) phenyl) -2- benzofuran-1-one, 3, 3'-bis (4-hydroxyphenyl) benzofuran-1-one and 3'-bis (4-hydroxyphenyl) benzofuran-1-one were combined with 3'-bis (3-hydroxyphenyl) benzofuran-1-one. The obtained dinitro was then reduced by zinc dust and hydrochloric acid. The reaction of 4, 4^* carbonyl diphthalic anhydride with amino acid L-alanine in acetic acid leads to the production of very high yields of chiral diacid monomer. As a result of the direct polymerization of these monomers, new optically active polymers were formed (amide-imide). In order to synthesize poly (amide-imide)/ZnO nanocomposites with different weight percentages (2, 4, 6, 8, and 10%), PAI and ZnO nanoparticles were combined using ultrasonication SEM, Fourier transform infrared spectroscopy, X-ray diffraction and thermal gravimetry were used to characterize the PAI films.

• 한국재료학회지
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• 제31권9호
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• pp.481-487
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• 2021

ZnO particles are successfully synthesized at 150 ℃ 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.

• 한국세라믹학회지
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• 제54권3호
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• pp.211-216
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• 2017

ZnO nanopowder was synthesized using a relatively facile and convenient glycol process. ZnO nanopowder was successfully synthesized at temperatures as low as $125^{\circ}C$ using zinc acetate as the Zn source and 1,4-butanediol as the solvent. Then, the effects of water content on the growth process and morphological evolution of ZnO powders were investigated using 1,4-butanediol and water as binary solvent mixtures. Using pure 1,4-butanediol at a temperature above $125^{\circ}C$, the prepared hexagonal ZnO nanopowder exhibited a quasi-spherical shape with average crystalline size of approximately 30 - 50 nm. It is also demonstrated that the morphology of ZnO powders can be controlled by the addition of various water content in 1,4-butanediol. With increasing water content, the morphologies of the ZnO powders changed sequentially from quasi-spherical to hexagonal plate and pyramid, and finally to hexagonal prismatic with a pyramidal tip. A sharp peak centered at 384 nm in the UV region and a weak broad peak in the visible region between 450 and 700 nm were shown in the room temperature PL spectra of the ZnO synthesized using the glycol process, regardless of the addition of water, suggesting that ZnO nanopowders with the best crystallinity were obtained under these conditions.

• 자연과학논문집
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• 제8권2호
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• pp.111-118
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• 1996

$Na_2O$-CaO-$SiO_2$ 계 유리의 화학적 내구성을 향상시키면서 작업점도의 변화를 최소화 하기 위하여, 기본 조성 유리를 선정한 후, 이 조성에 $B_2O_3$, ZnO 성분의 첨가량을 변화시키고 $Na_2O$, $Al_2O_3$, $Li_2O$ 성분을 변화시켜가면서 각 성분이 물성에 미치는 영향을 조사하여 최적 조성비를 얻는 것을 목적으로 하였다. 본 실험결과 $Na_2O$-CaO-$SiO_2$계 유리에서 연화점 변화를 최소화하고 화학적내구성을 극대화 시키는 최적조성(wt%)은 다음과 같았다.$B_2O_3$:3.36%, ZnO:2.88%, $Na_2O$:9.93%, $Al_2O_3$, $Li_2O$:0.19%, $SiO_2$:70.56%, CaO:11.22%, $K_2O$:0.14%

• 생물환경조절학회지
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• 제15권1호
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• pp.35-46
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• 2006

Objective of this research was to determine the effect of application rate of a slow release fertilizer (SRF) in three root media, peatmoss+vermiculite (1:1, v/v; PV), peatmoss+composted rice hall (1:1, v/v; PR), and peatmoss+composted pine bark (1:1, v/v; PB), on growth and nutrient contents of potted chrysanthemum 'Lima Honey'. All media contained polyacrylic acid sodium salt at a rate of $4.5g L^{-1}$. The fresh and dry weights at 43 days after transplanting did not show statistical differences among treatments in each root media. Elevated application rate of SRF increased fresh and dry weights at 80 days after transplanting in PV and PB media, but not in PR medium. Elevated application rates of SRF resulted in the increase of tissue phosphorus content and decrease of tissue Ca, Na, and Zn contents at both 43 and 80 days after transplanting. Elevated application rates of SRF resulted in the decrease of pH and increase of EC and concentrations of ${NO_3}^-$ and ${P_2O_5}^{3-}$, K, Ca, and Mg in the soil solution of PV and PR media. The trends of those in PR media were also similar except ${NO_3}^-$. The differences among treatments in EC at 80 days after transplanting were less significant as compared to those at 43 days after transplanting in three media.