• 한국막학회:학술대회논문집
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• 한국막학회 1995년도 춘계 총회 및 학술발표회
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• pp.26-27
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• 1995

Most of synthetic polymeric membranes used in ultrafiltration, reverse osmosis and microfiltration processes are prepared by phase inversion(or phase separation) technique. In this technique, a homogeneous polymer solution is cast into thin film or hollow fiber shape and then immersed into a nonsolvent coagulant bath. The exchange of solvent and nonsolvent across the interface between casting solution and coagu!ant can make the casting solution phase-separate and form a membrane with a symmetric or asymmetric structure. Because of importance of this technique in membrane field, many investigations have been dedicated to elucidate the mechanism of membrane formation by phase inversion technique.[1-10] These investigation have suggested that the structure formation and permeation properties of phase inversion membrane depend on the variables such as the nature and content of casting solution and coagulant, temperature of casting solution and coagulant, and the diffusional exchange rate of solvent and nonsolvent etc. which can be related to the thermodynamic and kinetic properties of the casting system. The variables such as the nature and content of casting solution can also be the important factor affecting the structure formation and permeation property of the phase inversion membrane.

• Membrane and Water Treatment
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• 제13권3호
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• pp.139-145
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• 2022

Development in advanced separation processes leads to the significant advancement in polymeric membrane preparation methodology. Therefore, present research investigated the preparation and characterization of cellulose acetate membrane by phase inversion separation method to determine optimized operating parameters. Prepared CA membrane's performance was been analyzed in terms of % rejection and flux. Investigation was conducted to study effect of different parameters such as polymer concentration, evaporation rate, thickness of film, coagulation bath properties, temperature of polymer solution and of the coagulation bath etc. CA membrane was fabricated by taking polymer concentration 10wt% and 11wt% with zero second evaporation time and varying film thickness over non-woven polyester fabric. Effect of coagulation bath temperature (CBT) and casting solution temperature were also been studied. The experimental results from SEM showed that the surface morphology had been changed with polymer r concentration, coagulation bath and casting solution temperature, etc. Lower polymer concentration leads to lower precipitation time giving porous membrane. The prepared membrane was tested for advanced waste water treatment of relevant effluent stream in pilot plant to study flux and rejection behavior of the membrane.

• 멤브레인
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• 제8권1호
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• pp.29-41
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• 1998

수용상 MPD(m-phenylene diamine)와 유기상 TMC(trimesoyl chloride)를 사용하여 역삼투 복합막의 활성층 고분자인 aromatic polyamide 제조를 행하고 그 성능을 고찰하였다. 또한 polysulfone 다공성 지지막 위에 박막을 회분, 연속식으로 계면중합 제조한 후, 제조변수에 따른 역삼투 성능을 비교하였다. 회분식으로 복합막을 제조한 결과 유기상 용매의 종류, 단량체의 농도와 함침시간, 열처리 온도, 중화제, 알코올 후처리, 산 후처리 등에 의해 다양한 성능을 나타내었다. 이때, 투과량 향상에는 알코올 후처리 효과가, 또 선택도의 향상에는 단량체의 농도와 함침시간이 변수이었다. 최적조건에서 연속식 공정으로 막모듈을 제조하여 NaCl 5,000 ppm, $25kg_f/cm^2$에서 상용막과 비교할때, 투과량은 33% 증가하고 배제율은 5% 감소하였다.

• 멤브레인
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• 제24권4호
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• pp.317-324
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• 2014

기존의 폴리아마이드 박막 역삼투 복합막(PA TFC RO Membrane)은 우수한 분리투과특성을 지니고 있으나 내염소성이 상대적으로 낮은 단점을 지니고 있다. 본 연구에서는 이를 해결하기 위하여 표면에 -OH나 -COOH 기가 도입된 다공성 지지체를 제조하고, 그 표면에 폴리아마이드 박막을 형성하여 역삼투 복합막을 제조하였다. 제조된 역삼투막의 구조 및 분리투과 특성은 여러 가지 기기분석 방법과 투과테스트 방법으로 분석하였다. 폴리아마이드 박막을 제조하기 위하여 아민계 단량체로는 메타-페닐렌 디아민(MPD)과 2,6-디아민 톨루엔(2,6-DAT)을 사용하였고, 디엑시드계 단량체로는 트리-메소일 클로라이드(TMC)를 사용하였다. 제조된 복합막의 투과도는 800 psi에서 약 $1.0m^3/m^2day$ 이상이었으며 이때 염배제율은 99.0% 이상이었다. 내염소성도 친수성기가 없는 폴리설폰 지지체를 사용한 복합막에 비하여 우수한 것으로 나타났다.

• 멤브레인
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• 제26권4호
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• pp.281-290
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• 2016

정삼투 분리막 용도에 적합한 폴리아미드 복합막의 제조에 있어 지지층의 극성 및 공극률이 폴리아미드 구조 및 정삼투 분리막 투과 성능에 미치는 영향을 살펴보기 위하여 클레쏘킬레이트 금속착물(0.1-0.5중량%)이 함유된 폴리술폰(18중량%) 용액을 상전이 공정을 통하여 지지층을 제조하였다. 제조된 지지층 상에 방향족 폴리아미드 활성층을 제막하였다. 다공성 PSF 지지층 제조를 위하여 상대적으로 낮은 폴리술폰(12중량%) 용액을 이용한 지지층을 폴리에스터 필름상에서 제조한 후 필름을 제거하고 제조된 지지층 상에 방향족 폴리아미드 활성층을 제막하였다. 제막된 시편 중 폴리술폰(18중량%)/금속착물(0.5중량%)로 만들어진 FO막은 유량 9.99 LMH, reverse salt flux 0.77 GMH로 HTI의 상용막(10.97 LMH, 2.2 GMH)과 비교해도 거의 비슷한 유량값과 향상된 RSF 값을 얻을 수 있었다. 캐스팅 용액의 금속착물의 첨가로 활성층 두께가 줄어들었으나 제거효율은 향상되는 결과를 얻을 수 있었다.

• 한국표면공학회지
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• 제39권6호
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• pp.255-262
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• 2006

Pd-Cu alloy membrane for hydrogen separation was fabricated by sputtering and Cu reflow process. At first, the Pd and Cu was continuously deposited by sputtering method on oxidized Si support, the Cu reflow process was followed. Microstructure of the surface and permeability of the membrane was investigated depending on various reflow temperature, time, Pd/cu composition and supports. With respect to our result, Pd-Cu thin film (90 wt.% Pd/10 wt.% Cu) deposited by sputtering process with thickness of $2{\mu}m$ was heat-treated for Cu reflow The voids of the membrane surface were completely filled and the dense crystal surface was formed by Cu reflow behavior at $700^{\circ}C$ for 1 hour. Cu reflow process, which is adopted for our work, could be applied to fabrication of dense Pd-alloy membrane for hydrogen separation regardless of supports. Ceramic or metal support could be easily used for the membrane fabricated by reflow process. The Cu reflow process must result in void-free surface and dense crystalline of Pd-alloy membrane, which is responsible for improved selectivity oi the membrane.

• 멤브레인
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• 제30권2호
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• pp.111-123
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• 2020

산업화와 기후 변화는 깨끗한 식수에 대한 수요 증가를 초래하였다. 막분리공정을 이용한 해수담수화는 물의 수요에 대한 요구를 채울 수 있는 경제적으로 실현 가능한 대안 중 하나이다. 막분리공정에서 2차원 재료들은 기존 역삼투분리막(reverse osmosis membrane) 기반의 폴리아마이드 박막복합막(TFC-PA)과 비교하였을 때 막의 강도를 높여주고 투수성을 용이하게 하며 높은 염제거율 및 높은 선속률과 선택성을 보여준다. 이 리뷰 논문에서는 재료, 합성, 특징, 해수담수화 과정을 기반으로 다양한 2차원 재료로 구성된 복합막들을 소개하고 있다.

• 한국막학회:학술대회논문집
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• 한국막학회 1995년도 제3회 심포지움 (분리막 연구의 최신동향)
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• pp.21-22
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• 1995

Gas separation science and technology is among the most rapidly growing areas involving membrane-based processes. Nitrogen enrichment of air, hydrogen recovery from a broad array of stream types, and removal of acid gases from natural gases are typical of the applications in this field. Great progress has been made in the discovery of guidelines optimization of polymer structures with simultaneously high permeabilities and selectivities for these important gas pairs. The development of thin-skinned asymmetric hollow fibers have also provided structures with extremely high permeation fluxes. Especially in the case of O$_{2}$/N$_{2}$ separations, the rate of improvements in new polymeric materials for gas separations appears to be slowing to a halt. Evidence will be presented, however, that the practical tradeoff between membrane permeability and selectivity has not been reached.

• 한국막학회:학술대회논문집
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• 한국막학회 1991년도 춘계 총회 및 학술발표회
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• pp.9-9
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• 1991

This paper will begin by describing osmosis and how reverse osmosis works. It will show how osmotic pressure affects reverse osmosis operations. It uill explain salt rejection, membrane flux, and recovery rates and the affect that salt built up has on membrane performance. It wil 1 explain the limitations of RO performance and why pretreatment is important. It will describe the two basic types of membrane, asymmetric and thin-film composite and explain the difference between these types plus compare cellulose acetate types to aromatic polyamide type membranes. It will discuss operating efficiences as it compares to feedwater pressure, concentration, temperature and pH. Finally, it will discuss the differences between tubular, plate and frame, hollow fiber and spiral wound element design. It will be a paper that talks about the basics of RO systems and should give a person who is unfamiliar with RO a basic introduction to this type of separation technology.

• Current Optics and Photonics
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• 제5권4호
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• pp.391-401
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• 2021

In the present study, a hyperelastic constitutive model is built by complying with a simplified hyperelastic strain energy function, which yields the numerical solution for a deformed polydimethylsiloxane (PDMS) membrane in the case of axisymmetric hydraulic pressure. Moreover, a nonlinear equilibrium model is deduced to accurately express the deformation of the membrane, laying a basis for precise analysis of the optical transfer function. Comparison to experimental and simulated data suggests that the model is capable of accurately characterizing the deformation behavior of the membrane. Furthermore, the stretch ratio derived from the model applies to the geometrical optimization of the deformed membrane.