• 접착 및 계면
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• 제10권1호
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• pp.17-22
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• 2009

Polymer thin films were prepared by radio frequency (RF) plasma polymerization of phthalic anhydride (PA). First, monomer vaporization temperature ($100{\sim}160^{\circ}C$) was optimized by evaluating the thermal properties of thin films using differential scanning calorimeter (DSC) and measuring the root-mean-square (RMS) roughness with atomic force microscope (AFM) at the fixed plasma power of 10 W and time of 5 min in a continuous-wave (CW) mode. Plasma power (5~20 W) was then optimized by measuring the film solubility in solvents such as toluene, acetone, dimethylsulfoxide (DMSO) and 1 methylpyrrolidine (NMP). Next, pulsed mode plasma polymerization was also studied by varying the duty cycle of on-time (5, 20%) under optimized conditions of continuous-wave (CW) mode ($120^{\circ}C$, 10 W) in order to increase the anhydride functional groups. Finally, polymer thin films were characterized by Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analyzer (TGA) and ${\alpha}$-step.

• Corrosion Science and Technology
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• 제17권3호
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• pp.123-128
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• 2018

The fabrication of a controlled surface is of great interest because it can be applied to various engineering facilities due to the various properties of the surface, such as self-cleaning, anti-bio-fouling, anti-icing, anti-corrosion, and anti-sticking. Controlled surfaces with micro/nano structures were fabricated using an ion beam focused onto a polypropylene (PP) surface with a fluoridation process. We developed a facile method of fabricating hydrophobic surfaces through ion beam treatment with argon and oxygen ions. The fabrication of low surface energy materials can replace the current expensive and complex manufacturing process. The contact angles (CAs) of the sample surface were $106^{\circ}$ and $108^{\circ}$ degrees using argon and oxygen ions, respectively. X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FT-IR) spectroscopy were used to determine the chemical composition of the surface. The morphology change of the surfaces was observed by scanning electron microscopy (SEM). The change of the surface morphology using the ion beam was shown to be very effective and provide enhanced optical properties. It is therefore expected that the prepared surface with wear and corrosion resistance might have a considerable potential in large scale industrial applications.

• Korean Chemical Engineering Research
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• 제52권2호
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• pp.209-213
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• 2014

A graft copolymer of poly(vinyl chloride)-g-poly(oxyethylene methacrylate) (PVC-g-POEM) was synthesized via atom transfer radical polymerization (ATRP) and used as a structure-directing agent to prepare $Al@Fe_2O_3$ core-shell nanocomposites through a sol-gel process. The amphiphilic property of PVC-g-POEM allows for good dispersion of Al particles and leads to specific interaction with iron ethoxide, a precursor of $Fe_2O_3$. Secondary bonding interaction in the sol-gel composites was characterized by Fourier transform-infrared (FT-IR) spectroscopy. The well-organized morphology of $Al@Fe_2O_3$ core-shell nanocomposites was observed using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Energy dispersive X-ray (EDX) and X-ray diffraction (XRD) were used to analyze the elemental composition and crystallization structure of the composites.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 추계학술대회 논문집 Vol.21
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• pp.137-137
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• 2008

In-situ doped polycrystalline 3C-SiC thin films were deposited by APCVD at $1200^{\circ}C$ using HMDS(hexamethyildisilane: $Si_2(CH_3)_6)$) as Si and C precursor, and 0 ~ 100 sccm $N_2$ as the dopant source gas. The peak of SiC is appeared in polycrystalline 3C-SiC thin films grown on $SiO_2$/Si substrates in XRD(X-ray diffraction) and FT-IR(Fourier transform infrared spectroscopy) analyses. The resistivity of polycrystalline 3C-SiC thin films decreased from 8.35 $\Omega{\cdot}cm$ with $N_2$ of 0 sccm to 0.014 $\Omega{\cdot}cm$ with 100 sccm. The carrier concentration of poly 3C-SiC films increased with doping from $3.0819\times10^{17}$ to $2.2994\times10^{19}cm^{-3}$ and their electronic mobilities increased from 2.433 to 29.299 $cm^2/V{\cdot}S$, respectively.

• 한국전기전자재료학회논문지
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• 제29권11호
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• pp.712-715
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• 2016

In this paper, we fabricated flexible CNT/PVDF piezoelectric composite device by introducing CNTs (carbon nanotubes) into PVDF (poly-vinylidene fluoride) solution using spray coating technique. Flexible PEDOT:PSS conducting polymer was used as electrodes. We tried to improve the piezoelectric performance from the CNT/PVDF composite film by increasing the portion of the ${\beta}$-phase PVDF in the film. We confirmed the structural conformation of the CNT/PVDF composite film as a function of CNT concentration by using FT-IR (fourier transform infra-red). As increasing CNT concentration, portion of the ${\beta}$-phase PVDF and resulting piezoelectric performance increased in the CNT/PVDF composite film. We found that CNTs introduced were played as seeds for formation of the ${\beta}$-phase PVDF in the CNT/PVDF composite film and resulting improvement of the piezoelectric performance.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2007년도 추계학술대회 논문집
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• pp.318-321
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• 2007

CdSe nanoparticles were prepared by chemical solution methods using $CdCl_2{\cdot}4H_2O$ (or $Cd(NO_3)_ 2{\cdot}4H_2O$) and $Na_2SeSO_3$. The characteristics of CdSe nanoparticles were controlled by the react ion time, reaction temperature and reaction method as well as the surfactants. Cetyltrimethyl ammonium bromide(CTAB) was used as a capping agent to control the chemical reactions in aqueous solution. Polyvinylalcohol(PVA) was used as a templet in sono-chemical method. CdSe nanoparticles synthesized in aqueous solution showed homogeneous size distribution with relatively stable surface. CdSe nanoparticles synthesized in non-aqueous solution containing diethanolamine(DEA) showed the structure transformation from cubic to hexagonal as the reduction temperature increased from 80 to $160^{\circ}C$. Core shell CdSe was synthesized by sono-chemical method. Characteristics of CdSe nanoparticles were analyzed using transmission electron microscopy(TEM), x-ray photoelectron spectroscopy(XPS), x-ray diffraction(XRD), UV-Vis absorption spectra, fourier transform infrared spectroscopy(FT-IR) and photoluminescence spectra spectroscopy(PL). This paper presents simple routes to prepare CdSe nanoparticles for solar cell applications.

• 한국세라믹학회지
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• 제49권1호
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• pp.111-117
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• 2012

Dependencies of thermal properties on the crystallization behavior of $0.9CaMgSi_2O_6-0.1MgSiO_3$ glass-ceramics were investigated as a function of heat-treatment temperature from $750^{\circ}C$ to $950^{\circ}C$. The crystallization behavior of the specimens depended on the heat-treatment temperature, which could be evaluated by differential thermal analysis (DTA), Fourier transform infrared spectroscopy (FT-IR), and X-ray diffraction (XRD) analysis by the Rietveld-reference intensity ratio (RIR) combined procedure. With an increase of the heat-treatment temperature, the thermal conductivity and thermal diffusivity of the heat-treated specimens increased. These results could be attributed to the increase of crystallization with heat-treatment temperature. However, the specific heat capacity of the heat-treated specimens was not affected by the heat-treatment temperature. The thermal conductivities measured from $25^{\circ}C$ to $100^{\circ}C$ were also discussed for application to lighting-emitting diode (LED) packages and substrate materials.

• 한국세라믹학회지
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• 제47권4호
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• pp.302-307
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• 2010

This study aims to synthesize emerald-green malayaite pigments using $CaCO_3$, $SiO_2$, $SnO_2$ and $V_2O_5$. For this purpose, the optimum composition is $CaV_{0.25}Sn_{0.687}SiO_5$ and heating condition is at $1250^{\circ}C$ for 6 h of soaking time. The samples were characterized by X-ray diffraction (XRD), the Fourier Transform Infrared Spectrometers(FT-IR), the Raman Spectrometer, Scanning Electron Microscope(SEM) and the UV/Vis spectroscopy. The substituted V ion for Sn was observed to be quadrivalence. The analytical results of the synthesized pigment showed the tetragonal crystal, a typical form of Malayaite, and the particle size to be approximately $5{\sim}10\;{\mu}m$. The color in lime glaze added 12 wt% pigment was emerald green, and CIE Lab parameters are $L^*=67.73$, $a^*=-12.39$ and $b^*=9.28$.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 춘계학술대회 논문집
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• pp.3-6
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• 2009

Aluminum nitride (AIN) thin films were deposited on a polycrystalline 3C-SiC intermediate layer by a pulsed reactive magnetron sputtering system. Characteristics of the AIN/SiC heterostructures were investigated by field emission scanning electron microscopy (FE-SEM), atomic force microscopy (AFM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FT-IR). The columnar structure of AIN thin films was observed by FE-SEM. The surface roughness of AlN films on the 3C-SiC buffer layer was measured using AFM. The XRD pattern of AlN films on SiC buffer layers was highly oriented at (002). Full width at half maximum (FWHM) of the rocking curve near (002) reflections was $1.3^{\circ}$. The infrared absorbance spectrum indicated that the residual stress of AIN thin films grown on SiC buffer layers was nearly negligible. The 3C-SiC intermediate layers are promising for the realization of nitride based electronic and mechanical devices.

• 한국전기전자재료학회논문지
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• 제27권1호
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• pp.39-44
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• 2014

Silicon nitride thin film deposited with Plasma Enhanced Chemical Vapor Deposition was treated by a nitrogen plasma generated by Inductively Coupled Plasma at room temperature. The treatment was investigated by Fourier Transform Infrared Spectroscopy and Atomic Force Microscopy on the surface at various RF source powers at two RF bias powers. The amount of hydrogen was reduced and the surface roughness of the films was decreased remarkably after the plasma treatment. In order to understand the causes, we analyzed the plasma diagnostics by Optical Emission Spectroscopy and Double Langmuir Probe. Based on these analysis results, we show that the nitrogen plasma treatment was effective in the improving of the properties silicon nitride thin film for flexible display.