• Proceedings of the Membrane Society of Korea Conference
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• 1997.10a
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• pp.79-80
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• 1997

1. 서론 : 열유도 상분리법(TIPS)은 일반적으로 상온에서 적정용매가 없는 고분자 소재를 아용하여 고분자-희석제 2성분계의 혼합물을 적절한 냉각 속도로 상분리 온도 이하로 급냉시켜 연속상과 분산상의 상분리를 일으킨 후 matrix전체에 다공성을 부여하여 분리막을 제조하는 공정이다. 폴리올레핀계 고분자를 중심으로 나일론11. 폴리카보네이트, PVC, ABS 수지 등을 소재로 plasmapheresis, 인공심폐기, breathing wear 등의 용도로 많이 응용되어 왔으며 현재 한외여과나 정밀여과 등 수투과 공정 및 battery separator 등으로의 응용이 활발하게 연구되고 있다. TIPS공정에 의해 제조된 고분자 분리막은 기존의 분리막에 비해 내열성 및 내약품성이 우수하며 여러 가지 다양한 변수로 부터 막의 미세구조를 조절할 수 있어 기공의 크기 및 모양이 조절 가능하다. 본 연구에서는 TIPS 공정을 이용한 고분자 분리막의 제조시 take-up speed와 air gap 등을 변화시켜 이에 따른 영향을 조사하였고 또한 cold stretching에 의한 구조변화를 알아보았다.

• Proceedings of the Membrane Society of Korea Conference
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• 1997.04b
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• pp.40-42
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• 1997

수처리 공정의 목적은 원수 중에 포함된 콜로이드, 미립자 등의 현탁물질, 이온과 유기물 등의 용해성 물질의 제거로, 이러한 목적을 위해서 수처리공정에 막분리 기술을 이용하는데 관심이 높아지고 있고, 이미 일부에서는 실용화되었다. 분리막에는 분리막의 기공의 크기에 따라 역삼투막, 한외여과막, 정밀여과막이 있으며, 대상 폐수 및 처리수의 재활용 여부에 따라 선정하여 사용한다. 본 연구에서는 폴리설폰 재질의 중공사하여 한외여과막을 사용하여 하천수를 처리하여 투과수와 원수의 수질을 비교함으로써, 분리막 기술에 의한 하천수처리의 타당성 및 처리 효율을 고찰해 보고자 하였다. 대상 원수로 최근 생활하수의 유입으로 수질이 악화되고 있는 소양강의 한 지류인 공지천의 물을 사용하였다.

• 한국신재생에너지학회:학술대회논문집
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• 2005.11a
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• pp.446-461
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• 2005

본 연구에서는 반응소결 탄화규소 다공질 지지체 개발을 위하여 SiC/C로 이루어진 성형체를 사용한 Si melt infiltration 공정 및 SiC/C/Si으로 이루어진 성형체를 사용하는 Si embedding 공정 개발이 이루어졌다. 개발된 반응소결 탄화규소 다공질 지지체의 기공률은 38% 이상이었으며 평균기공은 130 ${\mu}m$ 크기이었다. Si melt infiltration 방법으로 제조된 반응소결 탄화규소 다공질 지지체의 파괴강도는 상용 반응소결 탄화규소 지지체의 파괴강도보다 최대 200% 이상 높게 나타났다. 본 연구에서는 용융 Si의 침윤공정을 이용하여 반응소결 탄화규소 여과층을 갖는 반응소결 탄화규소 필터 및 그 제조공정이 개발되었다. 개발된 반응소결 탄화규소 필터의 필터 특성은 상용 탄화규소 필터의 필터 특성과 대체적으로 대등한 것으로 조사되었다.

• Membrane Journal
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• v.24 no.1
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• pp.50-62
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• 2014

An asymmetric microfiltration membranes were prepared with polysulfone by an immersion precipitation phase inversion method. Microfiltration membranes were prepared by polysulfone/N-methyl-2-pyrrolidone/polyvinylpyrrolidone/phosphoric acid casting solution and water coagulant. The vapor induced phase inversion method was used to prepare the membranes. The pore size and the morphology were changed by the phosphoric acid additive, the temperature of casting plate and the exposure time at the relative humidity of 74%. The morphology of membranes was investigated by scanning electron microscopy and microflow permporometer. By the addition of the phosphoric acid additive in the casting solution, the morphology of the prepared membranes were changed from a dense sponge structure to a loose asymmetric sponge structure. Due to the addition of catalytic amount of phosphoric acid to NMP casting solution, the mean pore size increased almost $0.2{\mu}m$ and the water flux increased about 3,000 LMH. The temperature of casting plate and exposure time had a apparent effect on the skin layer structure and the pore size and the porosity of the membrane.

• Membrane Journal
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• v.16 no.1
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• pp.31-38
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• 2006

The ceramic microfiltration system with periodic $N_2$-back-flushing was operated for treating paper wastewater discharged from a company making toilet papers by recycling milk or juice cartons. Two kinds of alumina membranes with 7 channels used here for recycling paper wastewater. The optimal filtration time interval for HC04 membrane with $0.4{\mu}m$ pore size was lower value of 4 min than 16 min for HC10 with $1.0{\mu}m$ pore size at fixed back-flushing time 40 sec, trans-membrane pressure $1.0kg_f/cm^2$ and back-flushing pressure $5.0kg_f/cm^2$. From the results of TMP effect at fixed filtration time interval and back-flushing time, the lower TMP was better on membrane fouling because high TMP could make easily membrane cake and fouling inside membrane structure. However, we could acquire the highest volume of total permeate at the highest TMP for the reason that TMP was driving force in our filtration system to treat paper wastewater. Then the permeate water of low turbidity was acquired in our microfiltration system using multi channels ceramic membranes, and the treated water could be reused in paper process.

• Membrane Journal
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• v.12 no.4
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• pp.207-215
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• 2002

The hindered diffusion in confined spaces is an important phenomenon to understand in a micro-scale the filtration mechanism determined by the particle motion in membrane pores. Compared to the case of spherical colloids, both the theoretical investigations and the experiments on the hindered diffusion of polyelectrolytes is actually more difficult, due to lots of relevant parameters resulting from the complicated conformational properties of the polyelectrolyte chain. We have successfully performed the Brownian dynamics simulations upon a single polyeiectrolyte confined in a slit-like pore, where a coarse-grained bead-spring model incorporated with Debye-Huckel interaction is properly adopted. For the given sizes of both the polyelectrolyte and the pore width, the hindered diffusion coefficient decreases as the solution ionic concentration decreases. It is evident that a charge effect of the pore wall enhances the hindered diffusion of polyelectrolyte. Simulation results allow us to make sense of the diffusive transport through the micro-pore, which is restricted by the influences of the steric hindrance of polyelectrolytes as well as the electrostatic repulsion between the polyelectrolytes and pore wall.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.27 no.4
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• pp.191-195
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• 2017

The microstructures of nonwoven fabric with and without nanofibers used as a filter for air purification type mask were investigated using scanning electron microscope. Moreover, we proposed a new mask design which is effective in the improvement of the fine dust blocking property. When comparing to nonwoven fabrics of which an average diameter was $25{\mu}m$, the nanofibers formed by the electrospinning process had a tight mesh structure arranged irregularly with a relatively large specific surface area, which could be associated with their much smaller diameter ranging from 25 to 120 nm. Such a prominent structural feature at nanofibers led to mechanical adsorption of fine particles, resulting in enhancement of filtering behavior maintaining high permeability. In addition to the excellent performance of the mask filter, wearing the mask properly is expected to maximize the blocking property of fine dust. To meet such a requirement, a new mask design that can be closely attached to the face in order to effectively block fine dust entering the gap between the face and the mask.

• Membrane Journal
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• v.8 no.2
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• pp.102-108
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• 1998

Permeation behavior of the semiconductor rinsing wastewater containing Si particles was examined by ultrafiltration using the polysulfone plate membrane. The permeation flux was gradually decreased with time. It was due to the growth of cake deposited on the membrane surface and the pore plugging by Si particles. Permeation flux of cross flow type was 1.4 times higher than that of the dead end flow type. Nitrogen back flushing which is the removing method of membrane fouling was superior to the water sweeping. With nitrogen back flushing, the decrease of permeation flux due to the fouling was recovered about 85 % to the initial flux in the flat plate membrane system. The rejection rate of Si particles was about 90 % and the size of Si particle in the permeate was about 70 nm.

• Journal of Energy Engineering
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• v.10 no.2
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• pp.120-131
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• 2001

최근 세라믹 필터에 대한 연구는 열악한 환경 및 산성가스에 대한 저항성으로 인해 고온 가스 여과에서 가장 전망 있는 기술로 부각되는 시점에 있다. 본 연구의 목적은 탄화규소(SiC) 세라믹 캔들 필터를 사용하여 IGCC와 PFBC의 새로운 전력생산 공정에서 배출되는 먼지를 제거하기 위한 필터성능을 조사하기 위함이다. 필터의 성능 평가는 고온.고압.고온.상압 조건에서 이루어졌으며 필터의 압력강하, 먼지 제거효율, 저항 계수, 그리고 열적.기계적 저항성 등을 파악하였다. 길이 30cm, 60cm 필터에 2종류의 먼지(코크스와 물유리 공정)를 이용하여 나타난 먼지 제거효율은 99.9% 이상을 보였으며 필터의 평균 기공 크기가 감소함에 따라 압력강하가 증가함을 확인하였다. 또한 탄화규소 세라믹 필터의 성능은 내부압력이 증가할수록 압력강하가 감소하고 유량이 증가할수록 압력강하가 증가함과 특히 유체에 대한 압력강하 변화는 온도의 영향보다는 상대적으로 내부압력에 더 많은 영향을 받음을 확인하였다.

• Membrane Journal
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• v.27 no.2
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• pp.199-204
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• 2017

In this study, a study was carried out for the separation of metal ions in lignin extract discharged from the pulp process. alumina powders were mixed with DMAc (N, N-dimethylacetamide) solvent and PESf (Polyethersulfone) polymer, PVP (polyvinylpyrrolidone) dispersant was added and slip casting method was used to prepare the membrane. The membrane was measured for pore size through a CFP (Capillary Flow Porometer) device and the surface and cross-section of the membrane were observed through a FE-SEM (Field Emission Scanning Electron Microscope). The flux was calculated by measuring the filtered weight per hour using a separation experiment device. Pore size measurements were performed under increasing pressure from 0 psi to 30 psi. The pore size of the membrane was $0.4{\mu}m$ and the flux decreased from the initial flux value of $6.36kg{\cdot}m^{-2}{\cdot}h^{-1}$ to $1.98kg{\cdot}m^{-2}{\cdot}h^{-1}$ due to the fouling of the membrane. After the permeation experiment, membrane contaminants were removed by simple washing. Separation experiments showed that Na contained in the initial lignin extract was reduced by 69%, Fe was removed by 87%, K by 95%, Ca by 93% and Mg by 96%.