• Membrane and Water Treatment
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• 제4권2호
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• pp.83-93
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• 2013

In the present investigation, were synthesized composite membranes prepared by simultaneous casting of two polymer solutions using the technique of phase inversion by immersion / precipitation. The support layer was prepared using polyethersulfone and polysulfone as base polymer and for the top layer was used sulfonated polysulfone (SPSU) with 50% sulfonation degree. The morphology of the resulting membranes were characterized by scanning electron microscopy (SEM). The final results showed that it is possible to prepare composite membranes by simultaneous casting of two polymer solutions with adherence between the two layers. Regarding the permeation tests, the developed membranes presented values of hydraulic permeability within the range of commercial nanofiltration (NF) membranes. Values rejection of 80% ammonium ions can be increased by using a SPSU with a greater degree of sulfonation.

• 멤브레인
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• 제10권2호
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• pp.66-74
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• 2000

In consideration that a high tensile strength and ion exchange capacity are maintained as the swelling of membrane is controlled by the coagulation of PSf with the introduction of ion exchange groups and PPSS without the introduction of ion exchange groups, the block copolymer of PSf and PPSS were synthesized. The cation exchange membrane was prepared by sulfonation with CSA and casted. The synthesized block copolymer and cation exchange membrane were characterized by FT-IR and their thermal stability was confirmed by TGA. The optimum sulfonation could be accomplished at a mole ratio of BPSf to CSA 1:3. The best electrochemical properties obtained by the optimal condition were area resistance of 4.37 $\Omega$ㆍ$\textrm{cm}^2$, ion exchange capacity of 1.71 meq/g dry membrane, water content of 0.2941 g $H_2O$/g dry membrane, and fixed ion concentration of 5.81 meq/g $H_2O$. When GBL was used as an additive, area resistance was increased by 13.7 % and ion exchange capacity was increased by 14.6%. When the membrane was fabricated in a form of composite using non woven cloth as a support. the tensile strength of membrane could be improved, but the electrochemical characteristics were not influenced.

• Membrane and Water Treatment
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• 제7권2호
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• pp.155-173
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• 2016

The present work has been focused on the development of polysulfone (PSf) ultrafiltration membrane via blending by sulfonated polyethersulfone (SPES) in order to permeability enhancement for ultrafiltration of cheese whey. In this regards, sulfonation of polyethersulfone was carried out and the degree of sulfonation was estimated. The effect of blend ratio on morphology, porosity, permeation and fouling of PSf / SPES membranes was investigated. Filtration experiments of whey were conducted for separation of macromolecules and proteins from the lactose enrichment phase. The morphology and performance of membranes were evaluated using different techniques such SEM, AFM, and contact angle measurements. The contact angle measurement showed that the hydrophilicity of membrane was increased by adding SPES. According to AFM images, PSf / SPES membranes exhibited lower roughness compared to neat PSf membrane. The water and whey flux of these membranes were higher than neat membrane. However, flux was decreased when the PSf / SPES blend ratio was 0/100. It can be attributed to pore size and morphology changes. Further, fouling parameters of PSf membrane were improved after blending. The blend membranes show a great potential to be used practically in proteins separation from cheese whey.

• Korean Membrane Journal
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• 제5권1호
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• pp.18-24
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• 2003

In order to improve the mechanical properties of the sulfonated polysulfone (SPSf) membranes previously synthesized in our laboratory, poly(vinyl alcohol) (PVA) was blended which is well known as the excellent physical and chemical properties. The resulting membranes blended with several molecular weight of PVA varying from 13,000 to 124,000 have been characterized to investigate the effect of PVA molecular weight in terms of ion conductivities, methanol permeabilities, water contents and ion exchange capacities for both heat treated and untreated membranes at 150$^{\circ}C$. The proton conductivity is decreased as the molecular weight of PVA increases. The plain SPSf-6.0 showed the proton conductivity of 0.078 S/cm whereas the blended membrane with M.W. 31,000 PVA indicated 0.04 S/cm. For methanol permeabilities, when PVA is added to SPAf-6.0, methanol crossover is increased because of the gain of the hydrophilicity from 3.4 to 6.5${\times}$10$\^$-6/ $\textrm{cm}^2$/s. For the annealed blended membranes (with M.W. 31,000 PVA), both the methanol corssover and proton conductivity showed very consistent values, about 2.3${\times}$10$\^$-6/ $\textrm{cm}^2$/s and 0.036 S/cm, respectively.

• 멤브레인
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• 제12권4호
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• pp.247-254
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• 2002

직접메탄올연료전지에 사용가능한 이온교환막을 개발하기 위하여 본 연구에서는 폴리설폰을 설폰화시켜 양이온교환막을 제조하였고 그에 대한 특성을 $150^{\circ}C$에서 열처리 전과 후를 통해 메탄을 투과도, 이온전도도, 이온교환용량 그리고 함수율 등에 대하여 평가하였다. 폴리설폰 고분자의 단량체와 설폰화제의 몰비가 1.4일 때 메탄올 투과도는 $2.87{\times}10^{-7} \;cm^2/s$(열처리 안함), $1.52{\times}10^{-7}\; cm^2/s$(열처리함)과 이온전도도는 1.10{\times}10^{-2}\; S/cm$ (열처리안함), 0.87{\times}10^{-2}\; S/cm$(열처리함)을 각각 보여 주었다. 그 이후의 몰비에서는 거의 증가하지 않았으며, 이러한 경향은 함수율과 이온교환용량에서도 같은 경향을 보여주었다.

• 전기화학회지
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• 제7권2호
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• pp.89-93
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• 2004

설폰화된 폴리설폰 (sulfonated polysulfone, SPSF)과 Poly(phenylmethyl silsequioxane) (PPSQ)의 유무기 복합 전해 질막을 제조하여 이온전도도와 메탄을 투과 특성을 조사하였다 클로로트리메틸실란과 클로로설폰산의 반응 몰비와 반응시간를 변화시켜 설폰화도가 $37\~75\%$인 SPSF를 합성하였다. SPSF/PPSQ복합 전해막은 SPSF와 PPSQ를 DMF에 용해하여 캐스팅하는 방법으로 제조하였다 이 복합 전해질막의 수소 이온 전도도는 상온에서 $2.8\times10^{-3}\~4.9\times10^{-2}S/cm$이었으며 설폰화도가 증가할수록 전도도는 증가하였다. 제조된 설폰화된 폴리설폰 복합 전해질막의 메탄을 투과도는 이온전도도와 설폰화도에 비례하여 증가하였으며, PPSQ의 함량이 커질수록 메탄을 투과도가 비례적으로 감소하는 것을 확인할 수 있었다. 약 $5wt\%$ PPSO론 포함한 복합 전해질막의 이온전도도 및 메탄을 투과도는 SPSF에 비교하여 거의 동일하지만 함수율을 크게 감소시키는데 효과적이었다.

• 멤브레인
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• 제9권3호
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• pp.170-177
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• 1999

Polysulfone을 술폰화하여 물-부탄올 용액의 분리를 위한 투과증발용 비대칭막을 제조하였다. 술론화제로는 chlorosulfoneic acid-trimethyulchlorosilane을 반응시킨 후 이용하였다. FT-IR과 $^1H$-NMR을 이용하여 치환여부를 살펴보았고 술폰화정도는 역적정법과 $^1H$H-NMR을 이용하여 구하였다. DSC와 TGA를 이용하여 열적특성변화를 알아보았다. 비대칭막을 제조하기 위하여 N-methyl-2-pyrrolidone(NMP)rhkdiethyleneglycol dimethyl ether (DGDE)의 혼합용매를 사용하였다. SEM을 이용하여 단면과 skinlayer 의 구조변화를 살펴보았다. 한 연구에서 제조한 비대칭막은 dense film에 비하여 물에 대한 선택도는 거의 변화가 없고 투과유량은 약 80배 정도 증가하였다.

• 멤브레인
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• 제24권4호
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• pp.292-300
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• 2014

내염소성을 갖는 염제거공정용 술폰화 폴리아릴렌 에테르 술폰 랜덤 공중합체(SPAES) thin film composite (TFC)막이 모노글라임 용매를 이용하여 제조되었다. 모노글라임은 선택층인 SPAES만을 용해시키며, 다공성 폴리술폰(예 : Udel$^{(R)}$)층에 대해 비용해성을 지녀, TFC 제조를 위한 선택적 용매로 사용될 수 있다. 또한 개미산이나 디에틸글리콜과는 달리, 환경적으로 무해하며, 매우 낮은 끊는점을 지녔다는 점이 또 다른 장점이 될 수 있다. 다공성 Udel$^{(R)}$ 지지체 위에 코팅시, 코팅용액이 기공구조에 침투하여 유수량을 감소시키는 기공투과현상이 발생하는데, 이를 최소화하기 위해 지지체를 이소프로필알콜과 글리세린 혼합액에서 전처리 후에, 코팅-건조 공정을 통해 결함이 없는 SPAES TFC로 제조된다. 또한, SPAES 선택층의 술폰화도, 고정이온의 염상태 및 물리-화학적 가교효과를 SPAES TFC막을 통한 투과거동과 관련하여 관찰하였다.