• Proceedings of the Membrane Society of Korea Conference
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• 한국막학회 1998년도 추계 총회 및 학술발표회
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• pp.166-168
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• 1998

막분리공정에서 분리막 오염은 투과율 감소에 큰 영향을 받는데 그 이유는 주로 막재질의 변질 및 막 표면에서의 농도 분극 현상에 기인하고 분리막의 종류 및 분획분자량의 차이에 따라 막분리 능력이 달라질 수 있다. 본 연구에서는 상용화되어 있는 UF/MF 중공사막에 미치는 막오염 정도와 세정 특성을 알아보았다. 막오염 정도는 막의 Pore size, 소재, 막구조에 따라서 단백질 수용액을 처리하여 막의 오염이 어떻게 일어나는지를 알아보았고 막오염 정도를 검토하기 위하여 초기순수에 대한 흡착후 투과량을 DOF(Degree of fouling)로 정의하였다. 막의 세정특성은 0.1N-NaOH을 사용하여 화학적 세정효과를 확인하였고 초기 순수에 대한 세정후 회복정도를 DOC(Degree of Cleaning)로 정의하였다. 또한 UF막에서 분획분자량별 특성과 MF막에서 소재별/구조적 특성이 DOF와 DOC에 미치는 영향에 대해서 알아보았다.

• Journal of the Korean Society of Food Science and Nutrition
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• 제17권4호
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• pp.365-370
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• 1988

한외여과법을 이용한 식품 페액의 단백질 분리, 회수에 관한 조작조건의 최적화를 위하여 cheese whey의 투과유속에 대한 세정효과의 영향과 조작압과 한계유속의 상관관계를 측정하여 다음의 결과를 얻었다. 세정의 효과로부터 유지 전용세제를 사용한 경우가 막의 투과유속의 회복율이 가장 높았으므로 whey중에 소량 함유되어 있는 유지분이 막의 투과유속의 저하에 큰 영향을 미침을 알 수 있었고, cheese whey를 한외여과법에 의하여 농축, 분리하는 경우 사용압력범위 $1{\sim}10kg/cm^2$에서 분획분자량 100,000인 막을 사용하는 경우 조작압력 약 $7kg/cm^2$에서 한계유속에 달하였으며, 그 이상으로는 압력을 가하여도 투과유속은 상승하지 않았다. 또한 이력현상의존재도 고려하여 볼 때 과도한 압력은 한외여과의 경우 투과유속의 상승에 효과가 없음을 알 수 있었다.

• Proceedings of the Membrane Society of Korea Conference
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• 한국막학회 1998년도 추계 총회 및 학술발표회
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• pp.159-162
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• 1998

폐수의 형태 및 성장과 막의 특성에 의해 한외여과는 처리수의 직접배출 또는 재 이용을 위해 사용되고 있다. 일본의 Masuda등은 1축 RDM을 사용하여 순수에서 회전에 따른 압력 강하를 관찰하고, 또 도시 하수처리 공정의 활성슬러지를 분리하기 위해 Aqua Renaissance '90프로젝트의 일환으로 도시 하수처리에 2축 RDM이 사용되었다. 동력학적 여과의 투과모델은 김제우 등에 의해 정립된 식을 이용하여 동력학적 여과기의 투과율(J)은 일반적으로 유효압력차($\DeltaP_T$), 벌크의 농도($C_B$) 그리고 회전속도 등에 의해 결정되어진다. 기존에 제시된 회전원판 모듈의 순수 투과에서 permeate side의 저항(Rp)값은 막자체의 저항(Rm)에 비해 상대적 작아 무시되었다. 본 연구는 1축 RDM 한외여과에서 투과율에 영향을 미치는 저항(R)에서 판자체에 변형을 주어 permeate side에서 저항(Rp)에 대한 영향에 관하여 연구를 수행하였다.

• Journal of Sericultural and Entomological Science
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• 제32권1호
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• pp.58-67
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• 1990

견 피브로인 막을 통한 투과실험으로, 종전의 견섬유로는 얻을 수 없었던 투과 및 확산거동에 대하여, Dual mechanism을 적용하여 고찰하였으며, 아울러 염료의 구조가 이러한 물리화학적 성질에 가지는 영향에 관해서 고찰한 결과를 요약하면 다음과 같다. 1) 전체적인 확산계수 $D_{(c)}$는 주로 Langmuir-type 확산계수 $D_{L}$에 의해서 결정된다. 2) 농도에 따른 확산계수의 조사에서 Dye I (monobasic dye)에서는 뚜렷한 최대치가 관찰되었으나, Dye III(trisulfonic acid dye)에서 $D_{p}$는 거의 의미가 없는 것으로 나타났다. 3) 견 피브로인에 있어서 산성염료의 확산은 sulfonic acid group의 도입에 따라 정점 느리게 되고, $D_{L}$은 온도의 증가에 따라 더 큰 값을 나타냈다. 4) 염료 음이온의 하전수가 클수록 확산계수는 chemical potential gradient model에 더욱 더 가깝게 된다. 5) 투과의 활성화 에너지는 sulfonic acid group의 도입에 따라 감소되었다.다.

• Membrane Journal
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• 제29권1호
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• pp.51-60
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• 2019

In order to improve gas separation properties of polymeric membranes which have been widely applied in the industry field, aluminosilicate hollow nanoparticles named as allophanes were synthesized by sol-gel method and formulated in Poly(dimethylsiloxane) (PDMS) matrix to investigate the gas separation properties of PDMS membrane. Transmission electron microscope (TEM), Energy dispersive X-ray analysis (EDX), X-ray diffractometer (XRD), Surface area and pore size analyzer (BET) and Fourier transform infrared spectrophotometer (FTIR) were carried out to characterize the synthetic allophanes. Then the PDMS mixed matrix membranes were prepared by adding different volume fraction of allophanes. To examine the effect of allophanes addition in PDMS matrix using unmodified allophane and modified ones, the gas permeation experiments were performed using oxygen, nitrogen, methane and carbon dioxide. As the volume fraction of modified allophane increased up to 4.05 Vol% the permeability of four test gases through PDMS mixed matrix membranes increased. Also, the selectivity of $O_2/N_2$ and $CO_2/CH_4$ increased with the contents of the modified allophane. Further improvement of gas separation properties of PDMS mixed matrix membranes containing higher volume percent of allophanes can be expected as long as well dispersion of allophanes in PDMS matrix can be achieved for better PDMS membranes.

• Applied Chemistry for Engineering
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• 제4권4호
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• pp.791-797
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• 1993

The application of the pervaporation process in biotechnology is rapidly growing. A two stage pervaporation process can be applied to the downstream processing of ethanol fermentation. In this paper, the second stage process in which the water-ethanol composition was 50:50 wt.% was investigated in more detail by using Nylon 4 and its blended membranes containing poly(vinyl alcohol) (PVA) and poly(acrylic acid) (PAA). Nylon 4 membranes were tested for compositions at 25, 30, and $35^{\circ}C$. Nylon 4 membranes had a separation factor of 4.18 with a permeability of $0.69kg/m^2hr$ at water-ethanol composition of 50:50 wt.%, while nylon 4-PVA blended membranes crosslinked by 5 Mrad gamma-ray irradiation showed a higher separation factor of 10.56 with permeability $0.55kg/m^2hr$ at the same composition. Nylon 4 also showed a high separation factor 27.8 at the ethanol-water azeotropic composition among the homopolymer membranes.

• Applied Chemistry for Engineering
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• 제9권4호
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• pp.469-474
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• 1998

Poly (vinyl alcohol) (PVA) membranes crosslinked with poly (styrene-co-maleic anhydride) (PSMAn) have been prepared by the solution method. To investigate the separation behavior of the crosslinked PVA/PSMAn membranes in the pervaporation process, the selective sorption experiment and swelling measurements of the membranes in ethanol-water mixtures of 30~90 wt % ethanol contents were conducted with equipment that was able to measure the concentration and amount of the liquid absorbed in the membranes. The membranes prepared in this study exhibited good selectivity toward water component in sorption and permeation. Also, in the feed containing ethanol more than 50 wt %, the permeation selectivity of the membrane showed better correlation with the sorption selectivity than that with the swelling ratio changing toward the crosslinking content. This behavior was consistence with a solution-diffusion model correlating permeation and sorption selectivity, and led to the conclusion that the permeation selectivity was determined by sorption step rather than by diffusion step in the membrane.

• Membrane Journal
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• 제16권1호
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• pp.68-76
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• 2006

This is the research about the concentration of trace citrus flavor components in water by pervaporation. We have investigated the permeation characteristics depending on the material and formation of membranes using four siloxane-based polymer composite membranes. We have also chosen the optimal membrane and investigated the permeation characteristics depending on the feed temperature, concentration and flow rate. And then it has been analyzed by using resistance-in series model. In the permeation experiment of citrus essence aroma model solution through the four siloxane-based polymer composite membranes, PVDF/POMS membranes have showed the best flavor flux and enrichment factor. As a result of the permeation experiment depending on the feed temperature, concentration and flow rate, we can find that as the feed temperature and concentration increase, the flavor flux increases while the enrichment factor decreases. And the flavor flux and enrichment factor increased as the flow rate increases.

• Korean Journal of Weed Science
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• 제5권1호
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• pp.85-88
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• 1985

Leakage of electrolytes from leaf discs of treated bean (Phaseolus velgaris L.) plant was the criterion used to investigate the effect of four herbicides on the permeability of leaf-cell membrane. CGA 82725 (2-propynyl 2-((3, 5-dichloro-2 pyridinyl) oxy) phenoxy prpanate) at $10^{-3}M$ increased significantly cell membrane permeability within 1 h after 12 h treatment. Significant increase in cell membrane permeability was also detected at $10^{-2}M$ of DOWCO 453 (Haloxy-methyl 2-(4 (3-chloro- 5-(trifuluoromethyl)-2-pyridinyl) phenoxy) propanate. The effect of dinoseb (2-(1-methylpropyl)-4, 6-dintrophenol) on cell premeability was detected at $10^{-4}M$ after 12h. The highest conductivity measurement was obtained from paraquat (1, 1'- dimethyl-4, 4'-bipyridinium ion). Increase in cell membrane permeability was not always associated with injury symptoms such as appearance of necrotic area in leaves.

• Membrane Journal
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• 제33권6호
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• pp.369-376
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• 2023

In this study, the alternative to the energy-intensive conventional vacuum distillation process, an eco-friendly and energy-efficient pervaporation separation was employed in 1,2 hexane diol/water (HDO/water) mixture. The crosslinked PVA-glutaraldehyde was coated inside the alumina hollow fiber membrane (Al-HF). In the HDO/IPA pervaporation separation, optimization of the membrane concerning PVA/GA ratio, curing temperature, and pervaporation operating condition were performed. In the long-term stability test, the sustainable pervaporation separation performance giving flux in the range of 1.90~2.16 kg/m²h, and water content in permeate was higher than 99.5% (separation factor = 68) was obtained from the PVA/GA (molar ratio = 0.08, curing temperature = 80℃) coated Al-HF membrane from HDO/water (25/75, w/w, %) mixture at 40℃. Therefore, this work provides potential and inspiration for PVA-based membranes to mitigate excessive energy requirements in HDO/water separation by pervaporation.