• Bulletin of the Korean Chemical Society
• /
• 제32권11호
• /
• pp.3861-3864
• /
• 2011

Rhodamine B dye (RB) has been introduced into the mesoporous silica (SBA15) and Ag anchored mesoporous silica by applying solution impregnation method. Surface treatment of SBA15 with 3-aminopropyltrimethoxysilane (APTMS) facilitates selective anchoring of the RB molecules on SBA15. The photoluminescence spectra of RB confined within SBA15 indicates higher emission intensity, than that of the RB solid, particularly in the presence of Ag nanoparticles. The significant enhancement in photoluminescence intensity is attributed to the local enhancement of the optical fields near the molecules by interactions with silver plasmons.

• 환경생물
• /
• 제23권4호
• /
• pp.374-378
• /
• 2005

A diffusion - precipitation method was developed to determine acid volatile sulfide (AVS) concentrations in freshwater sediments. This method uses silver nitrate as a sulfide trap solution and the concentration of trapped sulfide is determined gravimetrically. The proposed diffusion - precipitation method is more rapid and less expensive than previously developed purge- and - trap methods. Spiked sodium sulfide recoveries using this method $(97\~120\%)$ were similar with a previously developed diffusion - absorption method $(93.8\~115\%)$ and about $20\%$ greater than a previously developed purge-and-trap method $(74.6\~105\%)$. Detection limit of this method $(0.1\;{\mu}mole\;S\;g^{-l})$ was comparable with that of diffusion-absorption method $(0.06\;{\mu}mole\;S\;g^{-l})$ and purge-and-trap method $(0.05\~0.5\;{\mu}mole\;S\;g^{-l})$.

• 분석과학
• /
• 제12권2호
• /
• pp.171-175
• /
• 1999

Carbon paste electrodes, modified with podands containing more than two sulfur atoms, have been employed for the voltammetric determination of Ag(I) ion from aqueous solution. The voltammetric response was characterized with respect to paste composition, preconcentration method, kind of anion, variation of pH, Ag(I) ion concentration, and possible interferences. Linear calibration curves were obtained for Ag(I) ion concentration ranging from $1.0{\times}10^{-6}$ to $9.0{\times}10^{-5}M$, and detection limit was $5.0{\times}10^{-7}M$.

• 분석과학
• /
• 제15권1호
• /
• pp.91-95
• /
• 2002

Carbon paste electrodes, modified with 5,6,14,15-dibenzo-1,4-dioxa-8,12-diazacyclopentadeca-5,14-diene containing different ligating atoms of oxygen and nitrogen, have been employed for the voltammetric determination of Ag(I) ion from aqueous solution. The voltammetric response was characterized with respect to paste composition, preconcentration method, kind of anion, variation of pH, Ag(I) ion concentration, and possible interferences. Linear calibration curves were obtained for Ag(I) ion concentration ranging from $3.0{\times}10^{-6}M$ to $8.0{\times}10^{-5}M$, and detection limit was $8.5{\times}10^{-7}M$.

• Korean Chemical Engineering Research
• /
• 제56권3호
• /
• pp.410-415
• /
• 2018

Expanded graphite (EG)/Ag nanoparticle composites were synthesized by the chemical reduction of Ag ions, followed by the addition of expanded graphite into an Ag reducing solution. The prepared composites showed uniform dispersion of Ag nanoparticles on the surface of expanded graphite and exhibited relatively higher thermal conductivities than those of pure expanded graphite. In the case of 10% Ag content in the composite, the thermal conductivity in the thickness direction was 78% higher than the pure expanded graphite. We suggest that EG/Ag nanoparticle composites are a strong candidate for advanced heat spreading material.

• E2M - 전기 전자와 첨단 소재
• /
• 제8권3호
• /
• pp.254-260
• /
• 1995

A method is described for the design and fabrication of the sensor interface circuits on the Clark electrodes for the dissolved oxygen(DO). The discussion includes a method for the +5 V single-supply driving for the sensor circuits, which has low power comsumption for the front-end electronics. DO probe under test is composed of the Clark electrode with silver anode, gold cathode and the electrolyte of half saturated KCI solution and the FEP teflon memtrance for the oxygen penetration. Typical polarograms for the DO probes by using this sensor circuit reveals high accuracy over 99% of the I to V conversion. Partial pressure of oxygen obtained from the polarograms are well suited to the results calculated. It is expected that the proposed sensor circuits can be utilized into the customized IC for the battery-driven small-size DO meters.

• Bulletin of the Korean Chemical Society
• /
• 제31권9호
• /
• pp.2488-2492
• /
• 2010

A method is described for the determination of the Po nuclides in a water sample. After the Po nuclides were purified from interfering elements in a water sample using a manganese dioxide precipitation followed by a solvent extraction method, the Po nuclides were deposited onto the silver plate. A large volume of the water sample was effectively pretreated with manganese dioxide precipitation method. To determine the optimum conditions for plating Po, the effects of the pH, volume, temperature and time on the Po deposition were investigated in hydrochloric acid solution. The investigated determination method of Po nuclides with solvent extraction was applied to a tap water sample.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
• /
• pp.409-409
• /
• 2012

모바일 및 TV, 모니터 부분에서 AMOLED의 비약적인 시장 점유율 확대와 더불어 TFT 소자 부문에서도 많은 집중과 연구개발이 이루어지고 있다. 높은 이동도를 필요로 하는 AMOLED의 구동 회로에 채널층으로서 a-Si이 낮은 이동도로 인한 한계에 부딪히며 더 이상 쓰일 수 없게 되었고, 현재 우수한 이동도와 균일성, 제조 원가 절감의 효과 등 많은 장점을 보유한 산화물 TFT가 접목되고 있다. 현재까지 IGZO, ZnO 등이 많이 연구되며 실제로 AMOLED 용 TFT 소자에 적용 되고 있다. 본 연구에서는 산화물질인 ZTO (Zinc-Tin-Oxide)를 이용하여 TFT를 제작하였다. n-type 웨이퍼에 PECVD를 이용하여 $SiO_2$를 100 nm 증착한 뒤 spin coater로 ZTO용액을 30 nm 증착하였다. ZTO의 최적화된 열처리 온도인 $450^{\circ}C$에서 annealing을 해준 다음에 thermal evaporator로 source와 drain을 증착하였다. Gate 컨택을 위하여 웨이퍼 후면에 silver paste를 이용해 소자를 완성하였다. 산화물질 특성상 환경변화에 민감한 경향성을 보이기 때문에 현재 산화물 TFT는 신뢰성 분석에 많은 연구가 진행되고 있다. 완성된 ZTO TFT 소자를 빛과 수분에 일정한 시간 노출시킨 뒤 I-V 측정을 통하여 소자 열화를 분석하였다.

• KSBB Journal
• /
• 제18권1호
• /
• pp.35-38
• /
• 2003

양수 내에 존재하는 총 단백질을 이차원 전기영동을 이용하여 분리 분석하였고, gradient gel을 이용하여 양수 내에 소량으로 존재하는 미세 단백질까지 분리하였다. 양수 내에는 고농도로 존재하는 단백질이 있는데 이것이 serum albumin precursor임을 확인하였고, 8-18% gradient gel의 이용으로 분해능(resolution)이 향상되어 미세 단백질을 분리 분석할 수 있었다. 이차원 전기영동 후 MALDI-TOF를 이용하여 단백질을 identification하여 기존의 양수 protein database에 존재하는 단백질을 확인하였고, 존재하지 않는 새로운 단백질을 분리 분석하였다.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 1994년도 춘계학술대회 논문집
• /
• pp.130-132
• /
• 1994

We fabricated Ag ion exchange glass waveguide. Generally, ion-exchange glass waveguide. are suitable for passive integrated optical components such as directional and star couplers. Its advantages include low loss, ease of fabrication, and low material cost. So, we faricated Ag ion-exchange glass waveguides in AgNO$_3$ melt solution from 2 mole %. And we used Sodalime glass as a substrate in the fabrication process. As the results, we observed multivalent ion-exchange in a typical sodalime glass. Diffusion coefficient and depth are predicted by actual experimental data of Stewart. The exchange rate in silver-ion-exchanged waveguides are compared to the exchange time of waveguide fabrication.