• 분석과학
• /
• 제19권5호
• /
• pp.376-382
• /
• 2006

In this work, pitch/activated carbon/$TiO_2$ composite were prepared by $CCl_4$ solvent method with different mixing ratios. The BET surface area of pitch/activated carbon/$TiO_2$ composite has a significantly increase with increasing activated carbon content in pitch/activated carbon/$TiO_2$ composite. The surface structure and elemental compositions of the composite were studied by SEM and EDX, respectively. The SEM results were presented to the characterization of porous texture on the pitch/activated carbon/$TiO_2$ composite. And EDX data was shown the presence of C, O, S, Ti and other elements. The structural properties of the composite were studied in XRD measurements. The $TiO_2$ crystal phases of the pitch/activated carbon/$TiO_2$ composite had lots of rutile-type structure which transforms from anatase-type with a little of anatase-type structure. The photocatalytic activities of the composite were evaluated using a photo-decomposition method under UV lamp. The pitch/activated carbon/$TiO_2$ composites were observed better photocatalytic activity than that of pristine $TiO_2$.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 1999년도 추계학술대회 논문집
• /
• pp.366-369
• /
• 1999

The purpose of this study is to research and develop V2Os-AC(activated carbon) composite electrode for supercapacitor. Supaercapacitor cell of V2Os-AC composite electrode with 25P70FLiCIO$_{4}$/PC$_{10}$/EC$_{10}$ polymer electrolyte bring out good capacitor Performance below 3V. The discharge capacitance of V2Os-AC(30:70) composite with 70wt.% AC in 1st and 200th cycles was 9.6 and 8.2 F/g at current density of 1m7/cm2. The capacitance of V$_2$O$_{5}$-AC composite with 70wt.% AC capacitor was larger than that of others. The coulombic efficiency of supercapacitor at discharge process of 1 and 200 cycles were 96 and 100%, respectively. V$_2$O$_{5}$-AC composite supercapacitor with 70wt.% AC content showed good capacitance and stability with cycling.ing.ing.

• 멤브레인
• /
• 제25권2호
• /
• pp.107-114
• /
• 2015

PTMSP에 0~50 wt% NaA Zeolite를 첨가하여 PTMSP-NaA Zeolite 복합막을 제조하고, PTMSP-NaA Zeolite 복합막의 특성을 FT-IR, $^1H$-NMR, GPC, DSC, TGA, SEM에 의해서 조사하였다. PTMSP-NaA Zeolite 복합막의 수소와 질소에 대한 투과도와 선택성을 NaA Zeolite 함량에 따라 조사하였다. TGA측정에 의하면 PTMSP에 NaA Zeolite가 첨가되었을 때 복합막의 감량이 완결되는 온도는 낮아졌고, 감량(wt%)도 작아졌다. SEM관찰에 의하면 NaA Zeolite는 PTMSP-NaA Zeolite 복합막 내에 $2{\sim}5{\mu}m$ 크기로 분산되어 있었다. PTMSP-NaA Zeolite 복합막에 대한 $N_2$와 $H_2$의 투과도는 NaA Zeolite 함량이 증가하면 증가하였다. 그리고 PTMSP-NaA Zeolite 복합막의 $N_2$에 대한 $H_2$의 선택성은 NaA Zeolite함량이 증가하면 감소하였다.

• Journal of Electrochemical Science and Technology
• /
• 제2권1호
• /
• pp.51-56
• /
• 2011

We develop a new nonwoven composite separator for a safer lithium-ion battery, which is based on coating of silica ($SiO_2$) colloidal particles/styrene-butadiene rubber (SBR) binder to a poly(ethylene terephthalate) (PET) nonwoven support. The $SiO_2$ particles are interconnected by the SBR binder and closely packed in the nonwoven composite separator, which thus allows for the development of unusual porous structure, i.e. highly-connected interstitial voids formed between the $SiO_2$ particles. The PET nonwoven serves as a mechanical support that contributes to suppressing thermal shrinkage of the nonwoven composite separator. The $SiO_2$/SBR content in the nonwoven composite separators plays an important role in determining their separator properties. Porous structure, air permeability, and electrolyte wettability of the nonwoven composite separators, in comparison to a commercialized polyethylene (PE) separator, are elucidated as a function of the $SiO_2$/SBR content. Based on this understanding of the nonwoven composite separators, the effect of $SiO_2$/SBR content on the electrochemical performances such as self-discharge, discharge capacity, and discharge C-rate capability of cells assembled with the nonwoven composite separators is investigated.

• 한국세라믹학회지
• /
• 제34권7호
• /
• pp.747-757
• /
• 1997

ZSM-5 zeolite composite membranes have been synthesized from a silica sol solution containing TPABr as an organic template by the dip-coating and the pressurized-coating hydrothermal treatment techniques. The CO2 separation efficiency of synthesized composite membranes was also investigated. The permeation mechanism of CO2 through ZSM-5 membranses was the surface diffusion, and that of N2, O2, and He gases was Knudsen diffusion or activated diffusion depending on the synthetic method of membranes and the measurement temperature. The CO2/N2 separation factor of the membrane prepared by the dip-coating hydrothermal treatment was 2.5 at about 12$0^{\circ}C$, while the ZSM-5 composite membrane synthesized by the pressurized-coating hydrothermal treatment technique showed the CO2/N2 separation factor of 9.0 at room temperature higher than that ever reported in the literature.

• 한국분말재료학회지
• /
• 제11권2호
• /
• pp.143-148
• /
• 2004

In the present study, $TiO_2$ imbedded composite powders have been successfully prepared from the (Cu. Zn)/$TiO_2$ composite salt solution. The composite (Cu, Zn)/$TiO_2$ powders were formed by drying the solution at 200~$600^{\circ}C$ in the hydrogen atmosphere. Photocatalytic characteristics was evaluated by detecting the decomposition ratio of aniline blue with UV-visible spectrophotometer(Shimazu Co., UV-1601). Phase analysis of (Cu, Zn)/$TiO_2$ composite powders was carried out by XRD and DSC, and powder size was measured with TEM. The mean particle size of composite powders was about 100mm. As the reduction temperature increases, a few zinc sulfide and oxide phases was formed and copper oxide phase was reduced. The decomposition ratio of aniline blue was about 80％ under the UV irradiation by the TiO$_2$ phase in the composite (Cu, Zn)/$TiO_2$ powders and similar decomposition ratio of 80％ was obtained at the UV lightless condition by virtue of Cu and Zn compounds.

• 한국세라믹학회지
• /
• 제28권4호
• /
• pp.338-346
• /
• 1991

The alumina-titania composite powders coated with Al2O3 were prepared by the method of hydrolysis-deposition of mixed aluminium salt solution of Al2(SO)4-Al(NO3)3-Urea. The effects of coating-process parameters on the characteristics of coated composite powders were also investigated. As the content of TiO2 dispersed in deionized water increased, the coated composite powders were found to be more uniform in size and unagglomerated. When TiO2 powders were coated for 30 min, the optimum TiO2 content in the coating process was 400 mg/ι. The size of TiO2 particle was increased approximately from 0.7${\mu}{\textrm}{m}$ to 1.0${\mu}{\textrm}{m}$ through coating of Al2O3. The IEP of coated composite powders was pH=8.3 identical to the value of aluminium hydroxides and the zeta-potential showed nearly similar values each other. When heat treating coated composite powders at 130$0^{\circ}C$, only two phases of TiO2(rutile) and Al2TiO5 were observed. These results showed that the suface of TiO2 could be uniformly coated with the aluminium hydroxide.

• 한국세라믹학회지
• /
• 제34권5호
• /
• pp.535-543
• /
• 1997

The surface of SiC particles were partially oxidized to produce SiO2 layers on the SiC particles to prepare Al2O3/SiC composite by formation of mullite bonds between the grains of Al2O3 and SiC during sintering at 1$600^{\circ}C$. This process is considered to enable the sintering of Al2O3/SiC composite at lower temperature and also to relieve the stress, produced by thermal expansion mismatch between Al2O3 and SiC. In fact, Al2O3/SiC composite prepared by oxidation of SiC was observed to be more effectively sintered and densified at lower temperature. Maximum density, flexural strength and microhardness were obtained with 5.65 vol% of mullite content in Al2O3/SiC composite.

• 한국세라믹학회지
• /
• 제34권11호
• /
• pp.1129-1138
• /
• 1997

Al2O3/20 vol%YAG composite containing equiaxed grains and Al2O3/20 vol%LaAl11O18 composite containing elongated grains were fabricated using Al2O3-Y2O3 composition and Al2O3-La2O3 composition, respectively, by hot-pressing. In order to investigate the influence of microstructural control of second phase on toughening effect of toughened ceramic composites, AE (acoustic emission) measurements have been coupled with fracture toughness experiments(SENB and SEPB method). A separation of the fracture toughness and analysis of toughening mechanism was possible using the AE technique. The fracture toughness of hot-pressed materials was estimated to be 3.2 MPam0.5 for monolithic alumina, 4.7 MPam0.5 for Al2O3/20 vol%YAG composite and 6.2 MPam0.5 for Al2O3/20 vol%LaAl11O18 composite. In monolithic Al2O3, toughening does not occur as a result of either microcracking or grain bridging, whereas, composites exhibit toughening effects by both microcracking in the frontal zone and gain bridging in the wake zone, resulting in an improvement of fracture toughness as compared with monolithic Al2O3. The fracture toughness of Al2O3/20 vol%LaAl11O18 composite is higher than that of Al2O3/20 vol%YAG composite. It may be attributed to the elongated microstructure of Al2O3/20 vol%LaAl11O18 composite, resulting relatively greater bridging effect.

• 한국분말재료학회지
• /
• 제10권2호
• /
• pp.136-141
• /
• 2003

In the present study, $TiO_2$ imbedded copper matrix powders have been successfully prepared from the ($CuSO_4+TiO_2+Zn$) composite salt solution. The composite $Cu/TiO_2$ powders were formed by drying the solution at $200{\sim}~400^{\circ}C$ in the hydrogen atmosphere. Photocatalytic characteristics was evaluated by detecting TOC (total organic carbon) amount with TOC analyzer (model 5000A Shimadzu Co). Phase analysis of $Cu/TiO_2$ composite powders was carried out by XRD, DSC and powder size was measured with TEM. The mean particle size of composite powders was about 100 nm and a few zinc and copper oxide phases was included. The reduction ratio of TOC amount was 60% by the composite $Cu/TiO_2$ powders under the UV irradiation for 8 hours.