Defect control for large-scale thin-film composite membrane and its bench-scale demonstration

Yoo, Myung Jin,Lee, Jun Hyeok,Yoo, Seung Yeon,Oh, Jee Yeon,Roh, Jong Min,Grasso, Giuseppe,Lee, Jung Hyun,Lee, Dahun,Oh, Woong Jin,Yeo, Jeong-gu,Cho, Young Hoon,Park, Ho Bum Elsevier 2018 Journal of membrane science Vol.566 No.-

<P><B>Abstract</B></P> <P>Since the inception of membrane-based CO<SUB>2</SUB> separation technology in the late 1970s, a large number of material studies have been performed to improve the material properties of membrane materials and tremendous progress has been made with regard to CO<SUB>2</SUB> separation to increase the trade-off between permeability and selectivity, known as the “Robeson upper bound.” In membrane science, material properties and membrane properties are related but completely different, especially in thin-film composite (TFC) membranes. Compared to the large number of material studies, few studies have been performed on membrane properties, and very few membranes have been successfully commercialized because an extremely thin selective layer is required in CO<SUB>2</SUB>/N<SUB>2</SUB> separation membranes for high CO<SUB>2</SUB> permeance; however, defects are easily generated, deteriorating gas transport properties on a large-scale. In this study, we theoretically analyzed the effect of defects on the gas transport properties of a TFC membrane and introduced a method to control defects during the preparation of large-scale membranes. This work will provide a facile and practical approach to preparing TFC membranes and will be helpful toward extending material studies to real membrane demonstrations.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Requirements for a protective layer were proposed by theoretical calculations. </LI> <LI> Effectiveness of using a protective layer was proved by experiments. </LI> <LI> Protective layer coated membrane exhibited high CO<SUB>2</SUB> permeance & CO<SUB>2</SUB>/N<SUB>2</SUB> selectivity. </LI> <LI> Plate-and-frame membrane module was successfully prepared. </LI> <LI> Membrane-based CO<SUB>2</SUB>/N<SUB>2</SUB> separation system was demonstrated in bench-scale. </LI> </UL> </P>

Influence of Transport Properties of Laminated Membrane-fabric on Thermal Protective Performance Against Steam Hazard

Yun Su,Rui Li,Jie Yang,Chunhui Xiang,Guowen Song,Jun Li 한국섬유공학회 2019 Fibers and polymers Vol.20 No.11

The breathable fabric and membrane application in protective clothing designed for protection against flame,radiation, hot liquid and steam are vital in thermal protective performance and thermal comfort. Four kinds of laminatedmembrane-fabrics were selected to investigate the influence of configuration and properties of the fabric on thermalprotective performance under a pressurized steam hazard simulation. Surface morphology, water repellency, air permeability,water vapor permeability and other characteristics were evaluated to explore their impact on the mechanism of heat andmoisture transfer in laminated fabric. It is found that the configuration critically affects the thermal protective performance. The thickness, mass and moisture regain of laminated fabric exhibit different levels of positive correlation with thermalprotective performance of two configurations. Additionally, absorptive and porous membranes have different modes of watervapor transmission, while heat conduction and steam condensation in two kinds of membranes are both key influential factorsin producing skin burn under steam hazard. Therefore, effective protection against steam hazard is achieved by decreasing thepenetration and storage of steam within protective clothing.

Demonstration of large-scale graphene oxide/polymer thin-film composite membranes with protective layer

유승연,유명진,노종민,장준규,박호범 한국공업화학회 2019 한국공업화학회 연구논문 초록집 Vol.2019 No.1

Since CO₂ separation membrane requires a high permeance, a thin-film composite membrane having a thin selective layer has been manufactured. However, defects are prone to occur in the preparation of TFC membranes which have thin selective layer, especially large-scale membranes, and as a result, the CO₂ separation properties are reduced. Therefore, we demostrate the effect of defects on gas separation properties in TFC membranes. In order to control the defect, a defect-free large-scale membrane was manufactured by introducing protective layer. The gas transport properties were studied in single and mixed gas, and membrane module was tested in the same composition as the real process gases.

Identification of C4orf32 as a Novel Type I Endoplasmic Reticulum Resident Membrane Protein

Seung-Hwan Lee(이승환),Sang-Won Park(박상원),Jin-A Lee(이진아),Deok-Jin Jang(장덕진) 한국생명과학회 2019 생명과학회지 Vol.29 No.9

세포막 단백질의 topology는 막단백질의 중요한 특징이다. 우리는 이전에 C4orf32단백질을 클로닝 하였으나, 이 단백질의 세포내 위치나 topology는 알지 못했다. 이번 연구를 통해 C4orf32는 세포내에서 소포체에 위치되는 막단백질임을 알게 되었다. C4orf32의 topology를 알기 위해 protease protection assay, fluorescence protease protection (FPP) assay, FRB/rapamycin/FKBP system을 활용하였다. Protease protection assay와 FPP assay를 적용한 결과 C-말단에 GFP를 붙인 C4orf32-GFP의 경우 GFP가 소포체의 세포질 표면에 위치함을 확인할 수 있었다. 또한, FRB/rapamycin/FKBP시스템을 이용한 실험에서 rapamycin이 처리되지 않은 경우는 mRFP-FKBP가 세포질에 위치하다가 rapamycin이 처리되면 C4orf32-GFP-FR가 위치하는 소포체로 이동함을 확인할 수 있었다. 이러한 사실은 C4orf32의 C-말단이 소포체의 세포질쪽 면에 위치한다는 사실을 말해준다. 이러한 연구를 통해 C4orf32는 Type I 소포체 막단백질에 속한다는 사실을 확인할 수 있었다. Membrane topology is a key characteristic of membrane proteins. We previously reported the cloning of the chromosome 4 open-reading frame 32 (C4orf32) gene as a potential membrane protein; however, the cellular localization and membrane topology of C4orf32 was as yet unknown. In this study, we found that green fluorescent protein (GFP) fused to the C-terminus of C4orf32 (C4orf32-GFP) was localized to the endoplasmic reticulum (ER). We applied three tools to identify determinants of C4orf32 topology: protease protection, fluorescence protease protection (FPP), and an inducible system using the ternary complex between FK506 binding protein 12 (FKBP), rapamycin, and the rapamycin-binding domain of mTOR (FRB) (the FRB-rapamycin-FKBP system). Using protease protection and FPP assays, we found that the GFP tag in C4orf32-GFP was localized to the cytoplasmic surface of the ER membrane of HeLa cells. Protease protection and FPP assays are useful and complimentary tools for identifying the topology of GFP fusion membrane proteins. The FRB-rapamycin-FKBP system was also used to study the topology of C4orf32. In the absence of rapamycin, a monomeric red fluorescent protein–FKBP fusion (mRFP-FKBP) and C4orf32-GFP-FRB were localized to the cytoplasm and the ER membrane, respectively. However, in the presence of rapamycin, the mRFP-FKBP was shifted from the cytoplasm to the ER and colocalized with the C4orf32-GFP-FRB. These results indicate that the FRB moiety is facing the cytoplasmic surface of ER membrane. Overall, our results clearly suggest that C4orf32 belongs to the family of type I ER resident membrane proteins.

Edge protection using polyacrylonitrile thin-films for hydrocarbon-based membrane electrode assemblies

유덕만,김태호,남수환,윤상준,이장용,남상용,홍영택 한국공업화학회 2015 Journal of Industrial and Engineering Chemistry Vol.28 No.-

A hydrocarbon membrane-based membrane electrode assembly (MEA) is fabricated by attachingpolyacrylonitrile (PAN) films to a sulfonated poly(arylene ether sulfone) (SPAES) membrane to improvethe durability of a proton exchange membrane fuel cell (PEMFC) under cyclic hydration and dehydration. The edge protective PAN film is prepared by bar-coating to be extremely thin (6 1 mm thick) in order tominimize the increase in the MEA resistance. This study focuses on comparing the pristine membrane withthe membrane using the PAN film to identify the effect of the edge protective film. Therefore, durability testwith hydration–dehydration cycles is conducted to evaluate it

코너프로텍션 설치에 따른 멤브레인 LNG 저장탱크 시스템의 응력 및 변형거동 특성에 관한 수치해석

김청균(Chung Kyun Kim) 한국가스학회 2009 한국가스학회지 Vol.13 No.6

본 연구에서는 LNG 저장탱크의 단열재 공간에 설치된 코너프로텍션에 작용하는 응력 및 변형거동특성을 FEM으로 해석하였다. 제시된 코너프로텍션은 기존의 멤브레인식 LNG 저장탱크의 강도안전성과 LNG 누출안전성을 증대시킬 수 있다. LNG 저장탱크 시스템에 작용하는 응력과 변위 거동량을 단열재 상자, 멤브레인 내부탱크, PC 외부탱크에 대하여 해석하였다. 유한요소법으로 계산한 해석결과에 의하면, 내부탱크와 외부탱크 사이에 코너프로텍션을 설치한 새로운 LNG 멤브레인 저장탱크의 응력과 변형 거동량은 기존의 LNG 저장탱크에 비하여 현저하게 줄어드는 경향을 보여주고 있다. 이러한 현상은 LNG 저장탱크 시스템의 강도 안전성이 코너프로텍션을 설치함에 따라서 강성도가 증가하기 때문인 것으로 설명될 수 있다. In this study, the stress and deformation characteristics of corner protection in which is fabricated in an insulation area have been analyzed using a finite element method. The proposed corner protection may increase the strength and leakage safeties of conventional LNG storage system. The stress and deformation of LNG storage tank system are computed for an insulation panel box, membrane inner tank, and prestressed concrete outer tank. The FEM computed results indicate that the stress and displacement of new membrane LNG tank system with a corner protection between an inner tank and an outer tank are reduced in comparison to those of a conventional membrane LNG tank. This is explained that the strength safety of LNG membrane tank system may be increased due to a strength stiffness of a corner protection.

Edge protection using polyacrylonitrile fioms for hydrocarbon membrane-based membrane electrode assemblies

유덕만,남수환,윤상준,김태호,이장용,홍영택 한국공업화학회 2014 한국공업화학회 연구논문 초록집 Vol.2014 No.0

Changes in Cell Membrane Fatty Acid Composition of Streptococcus thermophilus in Response to Gradually Increasing Heat Temperature

민봉규,김꽃님,Vladimir Li,조서애,김희발 한국미생물·생명공학회 2020 Journal of microbiology and biotechnology Vol.30 No.5

In this study, a method of heat adaptation was implemented in an attempt to increase the upper thermal threshold of two Streptococcus thermophilus found in South Korea and identified the alterations in membrane fatty acid composition to adaptive response to heat. In order to develop heat tolerant lactic acid bacteria, heat treatment was continuously applied to bacteria by increasing temperature from 60°C until the point that no surviving cell was detected. Our results indicated significant increase in heat tolerance of heat-adapted strains compared to the wild type (WT) strains. In particular, the survival ratio of basically low heat-tolerant strain increased even more. In addition, the strains with improved heat tolerance acquired cross protection, which improved their survival ratio in acid, bile salts and osmotic conditions. A relation between heat tolerance and membrane fatty acid composition was identified. As a result of heat adaptation, the ratio of unsaturated to saturated fatty acids (UFA/SFA) and C18:1 relative concentration were decreased. C6:0 in only heatadapted strains and C22:0 in only the naturally high heat tolerant strain were detected. These results support the hypothesis, that the consequent increase of SFA ratio is a cellular response to environmental stresses such as high temperatures, and it is able to protect the cells from acid, bile salts and osmotic conditions via cross protection. This study demonstrated that the increase in heat tolerance can be utilized as a mean to improve bacterial tolerance against various environmental stresses.

Photodynamic antibacterial micro/nanofiber composite membrane with high efficiency and low resistance filtration performance for medical protective materials

Jia-Horng Lin,Lu Yang,Xianjin Hu,Haokai Peng,Haitao Ren,Ting-Ting Li,Ching-Wen Lou 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.128 No.-

Bacterial infection is one of the major threats to human health worldwide, posing a great challenge to thedevelopment of medical protective materials with efficient filtration and long-lasting antimicrobial properties. In this study, electrospinning technology and non-woven fabrics were combined to construct amicro/nano-structured photodynamic rechargeable and storable antibacterial filtration composite membrane. The filtration efficiency of the composite membrane is as high as 99.99% for 0.5–5 lm particles,and the resistance pressure drop is 85 Pa. In addition, the release of OH and H2O2 from the compositefilm reached 5326.16 lg/g and 711.93 lg/g, respectively. After 7 cycles of quenching, the charging capacityretains more than 70 % of the original. It showed good antimicrobial properties even when storedunder dark conditions for one month. The bactericidal efficiency of the composite membrane againstE. coli and S. aureus exceeded 99% under both dark and light conditions. The development of this simpleand clean micro/nanofiber membrane provides a new idea for exploring photoactive antimicrobial andfiltration materials for medical protection.

DNA vaccine encoding myristoylated membrane protein (MMP) of rock bream iridovirus (RBIV) induces protective immunity in rock bream (<i>Oplegnathus fasciatus</i>)

Jung, Myung-Hwa,Nikapitiya, Chamilani,Jung, Sung-Ju Elsevier 2018 Vaccine Vol.36 No.6

<P><B>Abstract</B></P> <P>Rock bream iridovirus (RBIV) causes severe mass mortalities in rock bream (<I>Oplegnathus fasciatus</I>) in Korea. In this study, we investigated the potential of viral membrane protein to induce antiviral status protecting rock bream against RBIV infection. We found that fish administered with ORF008L (myristoylated membrane protein, MMP) vaccine exhibited significantly higher levels of survival compared to ORF007L (major capsid protein, MCP). Moreover, ORF008L-based DNA vaccinated fish showed significant protection at 4 and 8 weeks post vaccination (wpv) than non-vaccinated fish after infected with RBIV (6.7 × 10<SUP>5</SUP>) at 23 °C, with relative percent survival (RPS) of 73.36% and 46.72%, respectively. All of the survivors from the first RBIV infection were strongly protected (100% RPS) from re-infected with RBIV (1.1 × 10<SUP>7</SUP>) at 100 dpi. In addition, the MMP (ORF008L)-based DNA vaccine significantly induced the gene expression of TLR3 (14.2-fold), MyD88 (11.6-fold), Mx (84.7-fold), ISG15 (8.7-fold), PKR (25.6-fold), MHC class I (13.3-fold), Fas (6.7-fold), Fas ligand (6.7-fold), caspase9 (17.0-fold) and caspase3 (15.3-fold) at 7 days post vaccination in the muscle (vaccine injection site). Our results showed the induction of immune responses and suggest the possibility of developing preventive measures against RBIV using myristoylated membrane protein-based DNA vaccine.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Injection of ORF008L (myristoylated membrane protein, MMP) vaccine offered high protection. </LI> <LI> TLR3, MyD88, Mx, ISG15, PKR, MHC class I, Fas, Fas ligand, caspase9 and 3 expressed high in vaccine group. </LI> <LI> The inflammatory cytokines (IL1β, IL8 and TNFα) were not enhanced in the ORF008L vaccinated group. </LI> </UL> </P>