• Journal of the Korean Graphic Arts Communication Society
• /
• v.16 no.2
• /
• pp.11-22
• /
• 1998

For the purpose of preparation of monodispersed spherical zinc oxide fine particles, an experimental research on the preparation of zinc oxide particles from zinc salts solutions by high temperature precipitation reaction was performed. Zinc oxide particles were precipitated from all the precipitation solutions tested if the precipitation temperature was higher than 60$^{\circ}$. As the precipitation temperature Increased until 80$^{\circ}$, the average particle diameter of zinc oxide particles decreased and the narrower particle size distribution were obtained. Spherical zinc oxide fine particles with relatively narrow particle size distribution were precipitated from the ZnSO$_4$ solutions with NaOH as precipitant. Final pH of precipitation solution had an effect on the amount of zinc oxide precipitated, but had no effect on the their particle size or size distribution.

• Journal of the Korean Graphic Arts Communication Society
• /
• v.16 no.1
• /
• pp.81-93
• /
• 1998

For the purpose of preparation of monodispersed spherical zinc oxide fine particles, and experimental research on the preparation of zinc oxide particles from zinc salts solutions by high temperature precipitation reaction was performed. Zinc oxide particles were precipitated from all the precipitation solutions tested if the precipitation temperature was higher than 60$^{\circ}$C. As the precipitation temperature increased until 80$^{\circ}$C, the average particle diameter of zinc oxide particles decreased and the narrower particle size distribution were obtained. Spherical zinc oxide fine particles with relativeyl narrow particle size distribution were precipitated from the ZnSo4 solutions with NaOH as precipitant. Final pH of precipitation solution had an effect on the amount of zinc oxide precipitated, but had no effect on the their particle size or size distribution.

• Transactions of the Korean hydrogen and new energy society
• /
• v.19 no.4
• /
• pp.305-312
• /
• 2008

ZnO/Zn redox cycle is the one of the promising thermochemical cycles for hydrogen production via water splitting with high temperature heat source like a concentrated solar energy. This paper reports the particle size effect of Zinc on water splitting behavior. Water splitting reaction experiments were carried out at isothermal conditions of 350 and 400$^{\circ}C$ in TGA (Thermo Gravimetric Analyzer) using four commercial Zinc powders (nano, <10 ${\mu}m$, <150 ${\mu}m$ and $150{\sim}600\;{\mu}m$ particle sizes). Before the experiments, average particle size of Zinc powders was analyzed by PSA (Particle Size Analysis). After the experiments, XRD (X-Ray Diffraction) and SEM (Scanning Electron Microscope) analyses were conducted on the samples. The experimental results showed that particle size had a effect on the conversion of Zinc to ZnO. Zinc conversion was increased, as the particle size decreased. Especially, the nano size particles were aggregated and the particle's morphology changed on the surface during hydrolysis reaction.

• Clean Technology
• /
• v.19 no.3
• /
• pp.249-256
• /
• 2013

The experiments have been performed to obtain zinc complex compound with smaller particle sizes, which is used as a charge control agent in manufacturing toner. Metallic salts and polyhydric alcohols have been studied to investigate their effects on the formation and the triboelectric charge of zinc complex-compound particle with different sizes. Reactants such as zinc chloride and 3,5-di-tert.-butyl salicylic acid have been used to form the complex compound. Polyethylene glycol (PEG-300), glycerin and ethylene glycol have been added into the zinc chloride solution beforehand to lower the reaction rate in the formation of zinc complex-compound. Aluminium(III) chloride has been mixed in the zinc chloride solution beforehand to restrain the particle size from growing. When PEG-300 and aluminium(III) chloride are used to lower the reaction rate and to restrain the particle size from growing, the average particle size of zinc complex compound decreases from $5.28{\mu}m$ to $2.33{\mu}m$, which was 44.1% of $5.28{\mu}m$.

• Applied Chemistry for Engineering
• /
• v.23 no.1
• /
• pp.8-13
• /
• 2012

The experiments have been performed to obtain zinc complex compound with smaller particle size, which is used as a charge control agent in manufacturing toner. Metallic salts and polyhydric alcohols have been studied to investigate their effects on the formation of different sizes of zinc complex-compound particle. Reactants such as zinc chloride and 3,5-di-tert-butyl salicylic acid have been used to form the complex compound. Polyethylene glycol (PEG-300), glycerin and ethylene glycol have been added into the zinc chloride solution beforehand to lower the reaction rate in the formation of zinc complex-compound. Zirconium (IV) oxychloride octahydrate has been mixed in the zinc chloride solution beforehand to restrain crystals from growing. When PEG-300 and zirconium (IV) oxychloride octahydrate are used to lower the reaction rate and to restrain the particle size from growing, the average particle size of zinc complex compound decreases from 5.28 to 1.84 ${\mu}m$, which is 34.9% of 5.28 ${\mu}m$.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.34 no.4
• /
• pp.117-124
• /
• 2024

Zinc oxide nanoparticles were synthesized using the polyol method with ethylene glycol containing hydroxyl groups (-OH). It was confirmed that the zinc compounds prepared by the polyol method were a mixture of zinc carbonate hydroxide (Zn₅(OH)₆(CO₃)₂) and zinc oxide (ZnO) crystalline structures. Calcination at 400℃, 600℃ and 800℃ was performed to examine the effects of calcination temperature on the particle size, morphology and crystallinity of zinc oxide. ZnO powders of calcination at 800 ℃ was evaluated to particle size analysis from ethylene glycol containing precursor solution compared with distilled water based solution. The zinc oxide particles obtained from the former had a particle size of approximately 404 ± 51 nm, whereas those from the latter exhibited a more uniform nanoparticles morphology with a particle size of approximately 109 ± 29 nm. This demonstrates that the addition of ethylene glycol can control the influence of water molecules, enabling the direct synthesis of zinc oxide in the form of uniform nanoparticles.

• Particle and aerosol research
• /
• v.4 no.2
• /
• pp.69-75
• /
• 2008

Nanosize ZnO particles were prepared by oxidation of zinc vapor and the particle growth was modeled by a coagulation model by assuming that the characteristic time for reaction was much shorter than coagulation time and residence time (${\tau}_{reaction}{\ll}{\tau}_{coagulation}{\ll}{\tau}_{residence}$). Experimental measurement of zinc oxide particles diameter was consistent with the predicted result from the coagulation model. For practical purpose of predicting zinc oxide size in areosol reactor, the constant kernel solution is concluded to be sufficient, Uniqueness of nano-scale property of zinc oxide was confirmed by the higher photocatalytic activity of zinc oxide than nanosize titania particles.

• Journal of Powder Materials
• /
• v.20 no.3
• /
• pp.186-190
• /
• 2013

The electrochemical performance for the corrosion of zinc anodes according to particle size and shape as anode in Zn/air batteries was study. We prepared five samples of Zn powder with different particle size and morphology. For analysis the particle size of theme, we measured particle size analysis (PSA). As the result, sample (e) had smaller particle size with $10.334{\mu}m$ than others. For measuring the electrochemical performance of them, we measured the cyclic voltammetry and linear polarization in three electrode system (half-cell). For measuring the morphology change of them before and after cyclic voltammetry, we measured Field Emission Scanning Electron Microscope (FE-SEM). From the cyclic voltammetry, as the zinc powder had small size, we knew that it had large diffusion coefficient. From the linear polarization, as the zinc powder had small size, it was a good state with high polarization resistance as anode in Zn/air batteries. From the SEM images, the particle size had increased due to the dendrite formation after cyclic voltammetry. Therefore, the sample (e) with small size would have the best electrochemical performance between these samples.

• Korean Chemical Engineering Research
• /
• v.49 no.6
• /
• pp.752-757
• /
• 2011

The effects of reaction temperature, reactant concentration, pH of solution and mixing order of reactants on the particle shape and size distribution of zinc oxide were investigated in the preparation of zinc oxide from ammonium hydroxide and zinc acetate by the method of aqueous hydrothermal precipitation method, and the photocatalytic ability of zinc oxide synthesized was measured from the degradation of tartrazine under UV irradiation. The average particle size was increased with pH of solution but decreased with zinc acetate concentration and reaction temperature. The optimum condition for the synthesis of minimum sized zinc oxide was pH 11.2, concentration of zinc acetate 0.6 M and reaction temperature $90^{\circ}C$, and its average particle size was 3.133 ${\mu}$m. 97% of tartrazine was degraded by zinc oxide in sixty minutes.

• Preventive Nutrition and Food Science
• /
• v.16 no.2
• /
• pp.174-178
• /
• 2011

The cell permeability and cytotoxic effects of different-sized zinc oxide (ZnO) particles were investigated using a human colorectal adenocarcinoma cell line called Caco-2. Morphological observation by scanning electron microscopy revealed that three zinc oxides with different mean particle sizes (ZnO-1, 20 nm; ZnO-2, 90~200 nm; ZnO-3, $1\sim5\;{\mu}m$) tended to aggregate, particularly in the case of ZnO-1. When cytotoxicities of all three sizes of zinc oxide particles were measured at concentration ranges of $1\sim1000\;{\mu}g$/mL, significant decreases in cell viability were observed at concentrations of $50\;{\mu}g$/mL and higher. Among the three zinc oxides, ZnO-1 showed the lowest viability at $50\;{\mu}g$/mL in Caco-2 cells, followed by ZnO-2 and ZnO-3. The permeate concentration of ZnO-1 from the apical to the basolateral side in the Caco-2 model system after four hours was about three-fold higher than that of either ZnO-2 or ZnO-3. These results demonstrated that ZnO-1, with a 20 nm mean particle size, had poorer viability and better permeability in Caco-2 cells than ZnO-2 and ZnO-3.