• 멤브레인
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• 제33권6호
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• pp.439-446
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• 2023

세라믹 분리막은 높은 열적, 화학적 안정성을 갖기 때문에 극한의 조건에서 운전되는 다양한 산업 공정에 적용할 수 있다. 그러나 투과도와 기계적 강도의 trade-off 현상에 의한 세라믹 분리막 활용에 제약이 있어, 고투과성-고강도 분리막의 개발이 필요하다. 본 연구에서는 상전이-압출법으로 알루미나 중공사 분리막을 제조하고, 고분자 바인더의 종류와 그 혼합비에 따른 분리막의 특성 변화를 관찰하였다. 용매인 DMAc (Dimethylacetamide)와 고분자 바인더의 한센 용해도 인자를 비교하면, PSf (polysulfone)가 DMAc와 높은 용해도 특성을 갖기 때문에 도프 용액의 점도와 토출압력이 높게 나타나 분리막 내부가 치밀한 구조로 형성되기 때문에 높은 기계적 강도를 갖으나 수투과도가 감소하는 것으로 확인되었다. 그에 반해, PES(polyethersulfone)를 이용하여 분리막을 제조하면 기계적 강도가 다소 감소하고 수투과도가 증가하는 것으로 나타났다. 따라서 분리막 성능과 물성을 최적화하기 위해 PSf와 PES를 혼합하여 분리막을 제조하였으며, 9:1로 혼합하여 제조된 분리막에서 최적화된 수투과도와 기계적 강도를 얻을 수 있었다.

• 한국막학회:학술대회논문집
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• 한국막학회 1996년도 춘계 총회 및 학술발표회
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• pp.62-64
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• 1996

Chitin, which is obtained mainly from the cuticle of a marine crustacean, has recently aroused great interest in its industrial and biomedical applications. Chitosan, deacetylated form of chitin, appears to be more useful for biomedical application and dehydration of aqueous solutions than chitin, since it has both hydroxyl and amino groups that can be modified easily. Amino groups on chitosan reacts with dialdehyde to form a Schiff base and then crosslinked, and can be easily neutralized with sulfuric acid and metal ions. Polyfunctional metal ions can form a metal-polyelectrolyte complexes with chitosan. Membranes used in modules so far working in industrial pervaporation plants are generally of composite type. This composite membrane was prepared by coating a porous polysulfone ultrafiltration membrane support of definite structure with a thin, dense layer of permselective chitosan. To apply industrial scale pervaporation process for dehydration of aqueous ethanol and isopropanol, chitosan composite membranes were prepared and tested at various conditions.

• 상하수도학회지
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• 제34권2호
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• pp.127-137
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• 2020

In this study, a MWCNT(multi-wall carbon nanotube) was added to polysulfone(PSf) support layer to improve flux of TFC(thin film composite) RO(reverse osmosis) membrane. Two different kinds of MWCNT were used. Surfaces of some MWCNTs were modified hydrophilically through acid treatment, while those of other MWCNTs were modified through heat treatment to maintain their hydrophobicity. MWCNT/PSf support layer was prepared by adding PSf to the NMP mixed solvent containing 0.1 wt% MWCNTs using a phase inversion method. The surface porosity of the MWCNT/PSf support increased by 42~46% while its surface pore size being maintained. The TFC RO membrane made of MWCNT/PSf support layer showed a 20% flux increase while its salt rejection characteristics is sustained. In addition, the MWCNT/PSf support layer has better mechanical stability than the PSf support layer, there resulting in an increased resistance of flux reduction due to physical pressure.

• 한국염색가공학회지
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• 제17권3호
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• pp.34-42
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• 2005

In this work, a practical separation performance was investigated on aqueous alcohol solutions, especially for iso-propyl alcohol (IPA), which is usually used during the semi- conductor rinsing process. The removal of various substances from waste aqueous IPA solutions was carried out by microfiltration with $0.1\~1{\mu}$m pore size of mean diameter as a pre-filter. Permeability and molecular weight cut-off of the functional polysulfone(PSf) ultrafiltration membrane to purify waste aqueous IPA solutions were measured through the ultrafiltration test. The solute rejection of PSf membrane had $92\%$ in 1,000ppm aqueous PEG solution with PEG molecular weight 10,000, the molecular weight cut-off had 10,000. The IPA concentration on the $CMPA-K^+$ membrane performance using pervaporation module system could be increased from $95.04 wt\%$ to more than $98.50wt\%$ in about 9hr at operation temperature of $70^{\circ}C$ using the pervaporation module system.

• Membrane and Water Treatment
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• 제11권2호
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• pp.159-166
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• 2020

In this study, the performance and antifouling properties of polysulfone (PSf) and polyvinylidene fluoride/polyvinylpyrrolidone (PVDF/PVP) membranes in a membrane bioreactor (MBR) were investigated. The membranes were prepared via phase inversion method, and then characterized by a set of analyses including contact angle, porosity and water flux and applied in a lab-scale MBR system. Soluble microbial product (SMP), extracellular polymeric substance (EPS), FTIR, gel permission chromatography (GPC) and particle size distribution (PSD) analyses were also carried out for MBR system. The results showed that the MBR with PSf membrane had higher hydrophobic organic compounds which resulted in formation of larger flocs in MBR. However, in this MBR had high compressibility coefficient of cake layer was higher (n=0.91) compared to MBR with PVDF/PVP membrane (n=0.8); hence, the fouling was more profound. GPC analysis revealed that compounds with molecular weight lower than 2 kDa are more formed on PSf membrane more than PVDF/PVP membrane. The results of FTIR analysis confirmed the presence of polysaccharide and protein compounds on the cake layer of both membranes which was in good agreement with EPS analysis. In addition, the results showed that their concentration was higher for the cake on PSf membrane.

• 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.

• 한국막학회:학술대회논문집
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• 한국막학회 2002년도 춘계 총회 및 학술발표회
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• pp.81-85
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• 2002

Small angle light scattering and field emission scanning electron microscope have been used to quantify the kinetics of liquid-liquid separation behavior during water vapor(RH52%[$\pm$3%] at 27$^{\circ}C$) quenching (non-solvent induced phase separation, NIPS) of polysulfone/NMP/Alcohol and CPVC/THF/Alcohol, respectively. Time dependence of the position of the light scattering maximum was observed at polysufone dope solutions, confirming spinodal secomposition (SD). while CPVC dope solutions showed a decreased scattered light intensity with a increased q-valuel, indicating nucleation & growth (NG). For the each system, domain growth rate in the intermediate and late stage of phase separation decreased with increasing the number of carbon of alcohol used as additive (non-solvent). Also, in the early stage for SD, the scattering intensity with time was in accordance with Cahns linear theory of spinodal decomposition,[1-3] regardless of types of non-solvent additive.

• 멤브레인
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• 제11권2호
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• pp.89-95
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• 2001

상전환 공정을 이용하여 무기 fluor인 cerium activated yttrium silicate (CAYS)가 함침재로 존재하는 폴리설폰 고분자막을 제조하였다. CAYS가 포함된 제막용액을 물 또는 이소프로파놀의 비용매 욕조에 침지시켜 고형화시켰을 때, 막에 함침되는 CAYS는 침지용 비용매에 따라 뚜렷하게 다른 함침 특성을 나타냄으로써, 제막용액의 고형화 경로를 추적할 수 있는 역할을 하였다. 물욕조에 침지되어 고형화된 막에서 무기물인 CAYS가 고분자 구조에 달라붙은 형상을 보여준 반면, 이소프로파놀에 침지되어 형성된 막에서는 셀 같은 기공 부분에 모여있는 것이 확인되었다. 이러한 현상은 제막용액의 침지 과정에서 무기함침재들이 액체-액체 상분리에 형성된 고분자 희박지역으로 집중되었음을 확인시켜 주었다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제18권4호
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• pp.8-18
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• 2013

Biocarrier beads with dead biomass, Bacillus drentensis, immobilized in polymer polysulfone were synthesized to remove heavy metals from wastewater. To identify the sorption mechanisms and theoretical nature of underlying processes, a series of batch experiments were carried out and a mathematical model was developed to quantify the biosorption of Pb(II) by the biocarrier beads. A series of mass balance equations for representing mass transfer of metal sorbents in biocarrier beads and surrounding solution were established. Major model parameters such as external mass transfer coefficient and maximum sorption capacity, etc. were determined from pseudo-first-order kinetic models and Langmuir isotherm model based on kinetic and equilibrium experimental measurements. The model simulation displays reasonable representations of experimental data and implied that the proposed model can be applied to quantitative analysis on biosorption mechanisms by porous granular beads. The simulation results also confirms that the biosorption of heavy metal by the biocarrier beads largely depended on surface adsorption.

• Membrane and Water Treatment
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• 제8권6호
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• pp.563-574
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• 2017

Antibacterial effective, high performanced, novel ZnO embedded composite membranes were obtained by blendig ZnO nanoparticles with polysulfone. IR, TG/DTG, XRD and SEM analysis were performed to characterize structure and morphology of ZnO nanoparticles and composite membranes. Contact angle, EWC, porosity and pore structure properties of composite membranes were investigated. Cross-flow filtration studies were performed to investigation of performances of prepared membranes. It was found from the cross section SEM images that ZnO nanoparticles dispersed homogenously up to additive amount of 2% and the membrane skin layer thicknesses increased in the presence of ZnO. Contact angle of pure PSf membranes were reduced from $70^{\circ}$ to $55^{\circ}$ after addition of 4% ZnO. Porosity of composite membrane contains 1% ZnO was higher about 22% than pure PSf membrane. BSA rejection ratio and PWF of 0.5% ZnO embedded composite membrane became 2.2 and 2.3 times higher than pure PSf membrane. It was determined from flux recovery ratios that ZnO additive increased the fouling resistance of composite membranes. Also, the bacterial killing ability of ZnO is well known and there are many researches related to this in the literature. Therefore, it is expected that prepared composite membranes will show antibacterial effect.