• Bulletin of the Korean Chemical Society
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• v.33 no.12
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• pp.3987-3992
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• 2012

Silver nanopowders were prepared from silver 2-ethylhexylcarbamate (Ag-EHCB) complexes by simple thermal reduction at $85^{\circ}C$ without any reducing agent in organic solvent. 2-Ethylhexylammonium 2-ethylhexylcarbamate (EHAEHC) was investigated in terms of their abilities to stabilize the silver nanoparticles (Ag-NPs) and its subsequent effects on the preventing aggregation between Ag-NPs. Conditions (concentration of stabilizer and reaction time) used to reduce Ag-EHCB complex were systematically varied to determine their effects on the sizes of Ag-NPs. The formation of the stabilized Ag-NPs were easily monitored by UV-vis spectroscopy and characterized by TGA, TEM, SEM and XRD. When EHAEHC was used as a stabilizer, Ag-NPs of 10-30 nm in diameter were easily obtained in high yield. Silver patterns were obtained from a silver nano-paste by heat treatment at $200^{\circ}C$ in air and were found to have resistivity values of $2.9{\times}10^{-8}\;{\Omega}{\cdot}m$.

• Journal of Haehwa Medicine
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• v.10 no.1
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• pp.167-174
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• 2001

According to the literatual study on the external treatment of premature ejaculation, the results were as follows. 1. Linition is inunction glans penis after infiltrate ASARI HERBA CUM RADICE(細辛), CARYOPHYLLI FLOS(丁香), CHEBULAE FRUCTUS(訶子), PAPAVERIS FRUCTUS(罌粟殼), FOSSILIA OSSIS MASTODI(龍骨), OSTREAE CONCHA(牡蠣 in oenostagma. 2. Retrojection or hypoatmism method is boiling CHINENSIS GALLA(五倍子), CNIDII FRUCTUS(蛇牀子) and hypoatmism, down temperature infiltrate glans penis. 3. Mesompharion apposition method is calorization VESPAE NIDUS(露蜂房), ANGELICAE DAHARICAE RADIX(白芷), and utilization vineger apposite mesompharion. 4. Medicament belt method is belt on lumbus and bythus by ROSAE LAEVIGATAE FRUCTUS(金櫻子), EURYALES SEMEN, OSTREAE CONCHA(牡蠣), TRIBULI FRUCTUS, AIPINIAE OXYPHYLLAE FRUCTUS(益智仁), NELUMBINIS SEMEN(蓮子肉) Powders. 5. Enema is injection in the rectum ANGELICAE GIGANTIS RADIX(當歸) effusion. 6. Much utilization agent are ASARI HERBA CUM RADICE(細辛), CHINENSIS GALLA(五倍子), OSTREAE CONCHA(牡蠣), CNIDII FRUCTUS(蛇床子), GRANATI PERICARPIUM(石榴皮), CARYOPHYLLI FLOS(丁香), CHEBULAE FRUCTUS(訶子), FOSSILIA OSSIS MASTODI(龍骨), VESPAE NIDUS(露蜂房), PAPAVERIS FRUCTUS(罌粟殼) etc. They are occupied in adstringentia, juventia, divergence agent, liver stabilizer agent.

• Polymer(Korea)
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• v.30 no.6
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• pp.505-511
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• 2006

We tried to prepare polystyrene composite particles containing carbon black by suspension polymerization with water as a reaction medium. Hydrophobic silica was selected as a stabilizer and oil-soluble azobisisobutyronitrile (AIBN), as an initiator. All polymerization reactions were carried out at a fixed temperature of $75^{\circ}C$. Stabilizer concentration was varied from $0.17{\sim}3.33wt%$ compared to water, where particles with $7.96{\mu}m$ in average diameter were obtained at 1.57 wt% of stabilizer. Increase in divinylbenzene concentration, as a crosslinking agent, from $0.1{\sim}1.0 wt%$ compared to monomer exhibited a large increase in average particle diameter Incorporation of 1wt% of carbon black compared to monomer produced an increase in average diameter It is speculated that viscosity lower than that necessary to induce even dispersion of carbon black particles led to poor dispersion, and as a result, large particles. For a styrene mixture containing 3 wt% carton black compared to monomer, enhanced dispersion due to an increase in carbon black concentration reduced average particle diameters. For styrene mixtures containing 1 and 3 wt% carbon black compared to monomer, preparticles before polymerization and polymer composite particles after polymerization showed a similar tendency towards particle formation. When carbon black concentration compared to monomer was increased to 5 and 7 wt%, styrene mixtures exhibited a large increase in viscosity and thus better dispersion of carbon black particles, which led to a decrease in preparticle diameters. However, these particles experienced agglomeration in the polymerization process, and polystyrene composite particles increased in average diameter.

• Applied Chemistry for Engineering
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• v.33 no.4
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• pp.386-393
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• 2022

In this study, the surface modification of calcium carbonate (CaCO₃) nanoparticles by a silane coupling agent, octyltrimethoxysilane (OTMS), was investigated and characterized using Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and thermogravimetric analysis (TGA) analysis. Both floating tests and contact angle measurements were also conducted to study the effect of OTMS concentration on the hydrophobicity of CaCO₃ nanoparticles. It was found that the active ratio for the CaCO₃ nanoparticles modified by 1 wt% of OTMS was 97.0 ± 0.5%, indicating that OTMS is a very effective silane coupling agent in enhancing the hydrophobicity of the CaCO₃ nanoparticle surface. The most stable foam was generated with 1 wt% of CaCO₃ nanoparticles in aqueous solutions at 1 wt% of OTMS, where the contact angle of water was found to be 91.8 ± 0.7°. It was also found that the most stable emulsion drops were formed at the same OTMS concentration. These results suggest that CaCO₃ nanoparticles modified by a silane coupling agent OTMS are a powerful candidate for a foam stabilizer or an emulsifier in many industrial applications.

• Journal of Advanced Technology Convergence
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• v.3 no.2
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• pp.25-31
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• 2024

In recent industrialization and development due to information and communication technology, modern women in modern society are exposed to physical and mental health due to numerous stresses. Popular inflammations are attributable to a decrease in lactic acid bacteria, frequent antibiotic use, and a decrease in immunity. It is necessary to develop products that are helpful and reflected. The inner care gel currently introduced on the market can increase beneficial bacteria and maintain a healthy y-zone. The inner gel contains a hydrogel component. 90% is made up of water, and other components act as support for supporting water and are formed through crosslinking between polymer chains. Hydroxyethyl cellulose (HEC) is a hydroxyethyl ethylenetel of cellulose. The purpose of use is to act as a binder, an emulsion stabilizer, a viscosity enhancer (water-soluble), and a film forming agent. CA (crosslinker) is a crosslinking agent and serves to bind. Hydrogel in the beauty field acts as a film forming agent that gently wraps around the skin by forming a thin film and serves as an emulsion stabilizer that helps to prevent separation of other raw materials. It also acts as a thickener by increasing viscosity in cosmetics. In addition, it is used for glucose monitoring, nursing care, cell transplantation, and wound treatment in the bio field. Currently, it is understood that no products using functional hydrogel have been released, so in this study, a Y zone care hydrogel solution was manufactured to find out the antibacterial properties of the functional hydrogel, and a new solution was developed. As a result, it was confirmed that the appropriate Ph was applied to the Y zone, and after culturing Candida albicans in PDB medium, all three products of the Y zone care hydrogel solution showed an antibacterial effect of 0.5-1.0mm

• Journal of Power System Engineering
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• v.5 no.2
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• pp.71-78
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• 2001

Using sodium hypophosphite as reducing agent, bath composition and plating condition of electroless copper plating on plating rate have been studied. The followings were determined as optimum, bath composition; $CuSO_4\;0.025M,\;NiSO_4\;0.002M,\;NaH_2PO_2\;0.4M$, sodium citrate 0.06M, $H_3BO_3$ 0.6M, thiourea or 2-MBT $0.2mg/{\ell}$, and operation conditions; pH $9{\sim}10$ at bath temperature rage of $60{\sim}70^{\circ}C$. A small amount of nickel ion($Ni^{2+}/Cu^{2+}$=0.002/0.025) to the hypophosphite reduced solution promotes autocatalysis and continuous plating. An additive such as thiourea or 2-MBT of a small amount($0.2mg/{\ell}$) can be used to stabilize the solution without changing plating rate much. The attivation energy between $20^{\circ}C\;and\;70^{\circ}C$ were calculated to be 11.3kcal/mol for deposition weight. Plating reaction had been ceased by the adjustment of pH above 13, temperature higher than $90^{\circ}C\;and\;under\;20^{\circ}C$. Deposited surface became worse in the case of increment of bath temperature above $80^{\circ}C$.

• Journal of the Korean institute of surface engineering
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• v.50 no.3
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• pp.177-182
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• 2017

The properties of electroless Ni-B thin film on diamond powder with different parameters (temperature, pH, surfactant etc.) were studied. The surface morphology, structure and composition distribution of the Ni-B film were observed by field effect scanning electron microscope (FE-SEM), energy-dispersive spectrometer (EDS), X-ray diffraction (XRD) and Auger electron spectroscopy (AES). The growth rate of Ni-B film was increased with increase of bath temperature. The B content in Ni-B film was reduced with increase of bath pH. As a result the structure of Ni-B film was changed from amorphous to crystalline structure. The PVP in solution plays multi-functional roles as a dispersant and a stabilizer. The Ni-B film deposited with adding 0.1 mM-PVP was strongly introduced an amorphous structure with higher B content (25 at.%). Also the crystallite size of Ni-B film was reduced from 12.7 nm to 5.4 nm.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2005.11a
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• pp.91-94
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• 2005

Polypropylene as a matrix has been used for wood polymer composites(WPC). In preparing WPC, the coupling agent, Polypropylene grafted Maleic Anhydride(PP-G-MA) was used in order to obtain a good interfacial bonding force between matrix and fillers and dispersion of wood powders. In this study, the effects of wood powder contents and water absorption on the mechanical properties were experimentally investigated. The tensile strength and flexural strength of composites reached its peak value when the wood powder content was around 60 wt%. However, the peak value of the impact was observed about 30 wt% of wood powder content. The tensile strength and flexural strength increase with increasing the wood power contents. But the impact strength decrease with increasing the wood powder contents. The slight change was observed with the water absorption in the WPC. The optimal condition of the compositions such as Anti-oxidant and UV stabilizers for the outdoor application was suggested in this research.

• Journal of Powder Materials
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• v.17 no.5
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• pp.390-398
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• 2010

Aqueous gold nanoparticle dispersion was synthesized by chemical reduction method using diethanolamine as reducing agent and polyethyleneimine as dispersion stabilizer. The synthesis conditions for the stable dispersion of the gold nanoparticle suspension were determined by changing the amount of the reducing agent and dispersant during the wet chemical synthesis procedures. The face centered cubic lattice structure of the gold nanoparticles was confirmed by using X-ray diffraction and the morphologies of the nanoparticles were observed by transmission electron microscope. The synthesized gold nanoparticle dispersion was concentrated by evaporating the dispersion medium at room temperature followed by the addition of ethyleneglycol as humectant for the increase of the elastic properties to obtain gold nanoparticle inks for direct ink writing process. The line patterns were obtained with the gold nanoparticle inks during the writing procedures and the morphologies of the fine patterns were observed by scanning electron microscope.

• Journal of the Korean Graphic Arts Communication Society
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• v.20 no.1
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• pp.65-78
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• 2002

The suspension polymerization of styrene was carried out to obtain the narrow-size distribution of particle by using poly(vinyl alcohol) (PVA) as suspension stabilizer according to the degree of hydrolysis and the molecular weight. The stabilizing properties of suspension are also dependent on the interfacial tension of aqueous solution when PVA is added. When the polymerization process was carried out with low hydrolyzed PVA, it gave single, well-defined particles, while high hydrolyzed PVA gave clusters. The size of particle produced in this study ranged between 5${\mu}{\textrm}{m}$ and 10${\mu}{\textrm}{m}$. The suspending agent, PVA, influences on the drop size and drop stability, When the molecular weight of PVA is increased, the drop size decreases and the drops become more stable toward coalescence. An increase in the PVA concentration decreases the mean drop size and narrows the drop size distribution.