• Bulletin of the Korean Chemical Society
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• v.35 no.7
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• pp.2004-2008
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• 2014

This paper reports the facile synthesis methods of zinc oxide (ZnO) nanoparticles, Z1-Z10, using diethylene glycol (DEG) and polyethylene glycol (PEG400). The particle size and morphology were correlated with the PEG concentration and reaction time. With 0.75 mL of PEG400 in 150 mL of DEG and a 20 h reaction time, the ZnO nanoparticles began to disperse from a collective spherical grain shape. The ZnO nanoparticles were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and a $N_2$ adsorption-desorption studies. The Brunauer-Emmett-Teller (BET) surface areas of Z4, Z5 and Z10 were 157.083, 141.559 and 233.249 $m^2/g$, respectively. The observed pore diameters of Z4, Z5 and Z10 were 63.4, 42.0 and 134.0 ${\AA}$, respectively. The pore volumes of Z4, Z5 and Z10 were 0.249, 0.148 and 0.781 $cm^3/g$, respectively. The photocatalytic activity of the synthesized ZnO nanoparticles was evaluated by methylene blue (MB) degradation, and the activity showed a good correlation with the $N_2$ adsorption-desorption data.

• Membrane and Water Treatment
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• v.9 no.5
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• pp.353-361
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• 2018

Fouling characteristics of humic substances on tight ultrafiltration (UF) membrane have been investigated. The tight UF membrane was prepared by blending polysulfone (PSf) in N.N-dimethylacetamide (DMAc) with 25%wt of Polyethylene glycol (PEG400) and 4%wt of acetone. Fouling characteristic of the modified PSf membrane was observed during peat water filtration in different trans-membrane pressure (TMP). It was found that the acetone modified membrane provided 13% increase in TMP during five hours of peat water filtration, where a stable flux was reached within 150 minutes. Meanwhile, the increase of TMP from 10 psig to 30 psig resulted in a fouling resistance enhancement of 60%. Furthermore, based on the fouling analysis, fouling mechanism at the first phase of filtration was attributed to intermediate blocking while the second phase was cake formation.

• Journal of Pharmaceutical Investigation
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• v.25 no.4
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• pp.339-345
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• 1995

For the effective treatment of aphthous stomatitis, the matrix type mucoadhesive patches containing triamcinolone acetonide have been formulated. The drug layer was obtained by drying the polymer gel which was prepared with carbomer 934P, ammoniomethacrylate copolymer, titanium dioxide and polyethylene glycol 400. The effects of the content of additives on physical characteristics of the polymer gel and the drug layer were evaluated. The addition of carbomer increased the yield point and the zero-shear viscosity of polymer gel as well as the thickness, the water absorption ratio, the adhesive time and $T_{50%}$ of drug layer. The adhesive time and the water absorption ratio of drug layer were also improved by the addition of ammoniomethacrylate copolymer, but the addition of titanium dioxide had decreased the zero-shear viscosity of polymer gel and the adhesive time of drug layer.

• Proceedings of the Korean Biophysical Society Conference
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• 1996.07a
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• pp.20-20
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• 1996

Crystals of a bacterial glutathione S-transferase(pGST) from pseudomonas sp. DJ 77 have been grown by hanging drop method of vapour diffusion from ammonium sulfate solution. The low concentration of polyethylene glycol 400 as additive were found to be essential for the reproducible growth of large single crystal of pGST. (omitted)

• Journal of the Korean Chemical Society
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• v.56 no.2
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• pp.246-250
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• 2012

An efficient access, single step and environmentally benign synthesis of a new series of pyrazole containing isoxazolines derivatives were prepared by the condensation of chalcones bearing pyrazole moiety with hydroxyl amine hydrochloride in basic condition by using polyethylene glycol-400 (PEG) as a greener reaction solvent. The advantages of the present methodology are mild reaction condition and avoidance of volatile organic solvent. Furthermore, these newly synthesized compounds were screened for their antimicrobial activity against various pathogens like Escherichia coli (MTCC 2939), Salmonella typhi (MTCC 98), Staphylococcus aureus (MTCC 96), Bacillus subtilis (MTCC 441), Aspergillus niger (MTCC 281), Aspergillus flavus (MTCC 2501), Penicillium chrsogenum (MTCC 160) and Fusarium moniliformae (MTCC 156). Especially compound containing the hydroxyl group in C2-position and presence of halo (I, Br and Cl) groups as substituents at $C_3$ and $C_5$ position on the benzene nucleus showed the higher activity. Furthermore, compounds bearing methyl groups in combination with I and Br which enhanced the activity.

• The Korean Journal of Food And Nutrition
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• v.19 no.4
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• pp.358-365
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• 2006

To study simultaneous water and solute transport kinetics during soaking in concentrated solution, the influence of the concentration and molecular weight of the solute(polyethylene glycol(PEG) and NaCl) in the soaking solution and the temperature on the water loss and solute gain rates were observed by using a model vegetable tissue(potato). When potato slices$(4cm{\times}4cm{\times}0.1cm)$ soaked in 60% PEG solutions, the water loss rate of the early phase decreased with increasing of the molecular weight of PEG from 200 to 6,000, while the final water loss increased with increasing the molecular weight of PEG and it reached to 80%. The cell wall of potato tissue was permeable to NaCl and PEGs of which average molecular weight is smaller than 400 but it was not permeable to PEG 600 and larger molecules. PEG which has average molecular weight below 600 induced plasmolysis and those above 600 induced cytorrhysis. The water loss rate of potato sample soaked in smaller molecular weight PEG solution was faster than those soaked in higher molecular weight PEG solution before cytorrhysis happened. The water loss rate was reversed after cytorrhysis happened. The volume change of potato within the first 60 minutes was larger in low molecular PEG solution but the final ratio of decreasing volume was larger in high molecular PEG solutions. In PEG 200 solution, the potato tissue was slightly shrinked without shape change. However, in PEG 4,000 solution, volume of potato was reduced significantly and potato tissue was twisted.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.5 no.1
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• pp.6-12
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• 1999

This study was conducted to investigate the application of edible films to Raymyun soup packaging. The sorption isotherm curve and BET monolayer moisture content of Raymyun soup were estimated as a basic experiment. Also, the mechanical properties, water vapor permeability, and solubility of the films were investigated. Methylcellulose, sodium caseinate, and K-carrageenan films were used as edible films and glycerol and polyethylene glycol(MW 400) were used as plasticizers. In case tensile strength, methylcellulose films was 68.56 MPa and sodium caseinate film was 7.11 MPa. The elongations of sodium caseinate, methylcellulose, and K-carrageenan film were 115.41%, 23.79% and 0.60%, respectively. The water vapor permeabilties values of methylcellulose, sodium caseinate, and K-carrageenan film between 50% and 70% RH were $0.25-0.38ng{\cdot}m/m^2{\cdot}sec{\cdot}Pa,\;0.62-0.84ng{\cdot}m/m^2{\cdot}sec{\cdot}Pa\;and\;0.31-0.55ng{\cdot}m/m^2{\cdot}sec{\cdot}Pa$, respectively. For the solubility of films, sodium caseinate film showed the highest solubility and methylcellulose film showed the lowest solubility.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.10 no.3
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• pp.271-277
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• 2000

Transparent $TiO_2$ thin films were prepared by the sol-gel method from titanium alkoxide aqueous solution containing large quantities of water. To prepare the aqueous system sol, the chelate compound solution were prepared from each 1 mole of titanium(IV)iso-propoxide, acetylacetone and 8 moles of isopropyl-alcohol. And then the 50 moles aqueous solution with the 0.02~0.50 moles of HCI for sol stability and the 0.3 mole of polyethylene glycol for coating adhesion were precisely dropped on the chelate compound solution. $TiO_2$thin films were fabricated by dip coating, drying and heat treatment at $400^{\circ}C$ and their characteristics were investigated by XRD, SEM and UV-visible spectrometer, The neutral sol of composition with TTIP : AcAc : IPA : $H_2O$ : PEG : HCl = 1 : 1 : 8 : 50 : 0.3 : 0.15 (molar ratio) was maintained stable sol condition and without problem for coating more than 30 days. The anatase phase $TiO_2$thin film prepared from 30 times dipping, drying and heat treating showed the flat surface and the fine microstructure of fracture surface with about 2 $\mu\textrm{m}$ thickness. Transparency of these $TiO_2$thin film was 80 % in the visible region.

• Archives of Pharmacal Research
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• v.18 no.3
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• pp.183-188
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• 1995

Polymeric reinforcement and coatings of alginate beads were carried out to control the release rate of drug from alginate beads. A poorly water-soluble ibuprofen (IPF) was selected as a model drug. A commercially available $Eudragit^{\circledR}$ RS100 was also used as a polymer. Effects of polymeric contents, the presence of plasticizers and amount of drug loading on the release rate of drug were investigated. The release rate of drug from alginate beads in the simulated gastric fluid did not occur within 2 h but released immediately when dissolution media were switched to the simulated intestinal fluid. No significant difference of release rate from polymer-reinforced alginate bead without plasticizers was observed when compared to plain (simple) beads. However, the release rate of drug from polymer-reinforced alginate beads was further sustained and retarded when aluminium tristearate (AT) as a plasticizer was added to polymer. However, polyethylene glycol 400 (PEG400) did not change the release rate of drug from alginate beads although PEG400 was used to improve dispersion of polymer and sodium alginate, and plasticize $Eudragit^{\circledR}$ RS100 polymer. The presence of plasticizer was crucial to reinforce alginate gel matrices using a polymer. As the amount of drug loading increased, the release rate of drug increased as a result of decreasing effects of polymer contents in matrices. The significantly sustained release of drug from polymer-coated alginate beads occurred as the amount of polymer increased because the thickness of coated membrane increased so that cracks and pores of the outer surface of alginate beads could be reduced. The sustained and retarded action of polymer-reinforced and coated beads may result from the disturbance of swelling and erosion (disintegration) of alginate beads. From these findings, polymeric-reinforcement and coatings of alginate gel beads can provide an advanced delivery system by retarding the release rate of various drugs.

• Journal of Powder Materials
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• v.29 no.4
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• pp.291-296
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• 2022

The green body of WC-Co cemented carbides containing polymeric binders such as paraffin, polyethylene glycol (PEG), and polyvinyl acetate (PVA) are prepared. The green density of the WC-Co cemented carbides increases with the addition of binders, with the exception of PVA, which is known to be a polar polymeric substance. The green strength of the WC-Co cemented carbides improves with the addition of paraffin and a mixture of PEG400 and PEG4000. In contrast, the green strength of the WC-Co does not increase when PEG400 and PEG4000 is added individually. The compressive strength of the green body increases to 14 MPa, and the machinability of the green body improves when more than 4-6 wt% paraffin and a mixture of PEG400 and PEG4000 is used. Simultaneously, the sintered density of WC-Co is as high as 99% relative density, similar to a low binder addition of 1-2 wt%.