• 한국물환경학회지
• /
• 제28권5호
• /
• pp.639-645
• /
• 2012

The purpose of this study is to identify the possibility of the CMP wastewater treatment from semiconductor fabrication under operating tubular membrane with coagulants. To find suitable coagulants treating CMP wastewater, we conducted Jar-test. After Jar-test experiments suitable coagulants are PAC(17%), $Ca(OH)_2$ and optimum coagulant dosage is PAC(17%) 10mg/L, $Ca(OH)_2$ 110 ~ 120mg/L. Based on these results, the tubular membrane was applied to CMP wastewater, the turbidity removal efficiency is $Ca(OH)_2$ > PAC(17%) > Nothing. The fast cross-flow velocity and backwash process what are operating characteristics of tubular membrane can be stable CMP wastewater treatment. But when the coagulant and tubular membrane are used at the same time, the withdraw and treatment of the CMP wastewater are possibile. However further treatment process needs if treated water will be used for semiconductor fabrications.

• 한국수소및신에너지학회논문집
• /
• 제21권4호
• /
• pp.264-270
• /
• 2010

Recently, the most promising methods for high purity hydrogen production are membranes separation such as polymer, metal, ceramic and composites. It is well known that Pd and Pd-alloys membranes have excellent properties for hydrogen separation. However, it has hydrogen embrittlement and high cost for practical applications. Therefore, most scientists have studied new materials instead of Pd and Pd-alloys. On the other hand, TiN powders are great in resistance to acids and chemically stable under high operating temperature. In order to get specimens for hydrogen permeation, the TiN powders synthesized were consolidated together with Co, Ni powders by hot press sintering (HPS). During the consolidation of powders at HPS, heating rate was 10 K/min and the pressure was 10 MPa. It was characterized by XRD, SEM. Also, we estimated the hydrogen permeability by Sievert's type hydrogen permeation membrane equipment.

• 공업화학
• /
• 제34권3호
• /
• pp.213-220
• /
• 2023

혼합기질막(mixed-matrix membrane, MMM)은 고성능 충전제가 고분자 기질에 분산된 구조로, 지난 30년간 이를 이용한 기체분리 연구가 집중적으로 수행되었다. 일반적으로 MMM은 고분자 막보다 우수한 기체 분리 성능을 가지고 있으며, 다결정 막에 비해 좋은 확장성을 보인다. 그러나 이러한 잠재성에도 불구하고, MMM의 상용화는 여러 가지 어려운 문제들로 인해 지연되고 있다. MMM의 주요 문제 중 하나는 충전제와 고분자 사이의 부적절한 계면 상호작용으로 결함(즉, 개면 공극 등)이 형성될 수 있다는 것이다. 따라서 많은 MMM 연구에서 이러한 계면의 문제를 해결하기 위한 전략이 제시되었다. 하지만 계면상의 상호작용으로 MMM이 가진 문제점들을 해결하려는 과학적 접근에 비해 손쉽고 효과적으로 대면적의 MMM을 제조하기 위한 공학적 접근은 상대적으로 간과되어 왔다. 본 총설에서는 MMM의 대면적화를 위한 공학적인 접근 중 하나인 고분자 변형을 통해 가능해진 금속-유기 골격체(metal-organic framework, MOF)의 원위치 형성을 이용한 MMM 제막 방법을 소개하고자 한다. 이 새로운 제막법은 현재 MMM이 직면하고 있는 문제들을 공학적인 접근으로 효과적으로 해결하여 MMM의 상용화를 촉진시킬 수 있다.

• The Korean Journal of Ceramics
• /
• 제7권1호
• /
• pp.36-40
• /
• 2001

In order to fabricate uncooled IR sensors for pyroelectric applications, multilayered thin films of Pt/PbTiO$_3$/Pt/Ti/Si$_3$N$_4$/SiO$_2$/Si and thermally isolating membrane structures of square-shaped/cantilevers-shaped microstructures were prepared. Cavity was also fabricated via direct silicon wafer bonding and etching technique. Metallic Pt layer was deposited by ion beam sputtering while PbTiO$_3$ thin films were prepared by sol-gel technique. Micromachining technology was used to fabricate microstructured-membrane detectors. In order to avoid a difficulty of etching active layers, silicon-nitride membrane structure was fabricated through the direct bonding and etching of the silicon wafer. Although multilayered thin film deposition and device fabrications were processed independently, these could b integrated to make IR micro-sensor devices.

• 대한전기학회논문지:전기물성ㆍ응용부문C
• /
• 제55권2호
• /
• pp.88-92
• /
• 2006

We present a microfluidic system with microvalves and a micropump that are easily integrated on the same substrate using the same fabrication process. The fabricated microfluidic system is suitable for use as a disposable device and its characteristics are optimized for use as a micro chemical analysis system (micro-TAS) and lab-on-a-chip. The system is realized by means of a polydimethylsiloxane (PDMS)-glass chip and an indium tin oxide (ITO) heater. We demonstrate the integration of the micropump and microvalves using a new thermopneumatic-actuated PDMS-based microfluidic system. A maximum pumping rate of about 730 nl/min is observed at. a duty ratio of 1 $\%$ and a frequency of 2 Hz with a fixed power of 500 mW. The measured power at flow cut-off is 500 mW for the microvalve whose channel width, depth and membrane thickness were 400 $\mu$m, 110 $\mu$m, and 320 $\mu$m, respectively.