DOCSLIB.ORG

Molecular Interactions Between Proteins and Synthetic Membrane Polymer Films Frederic Pimet,+Eric Perez,? and Georges Belfort*

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Molecular Interactions Between Proteins and Synthetic Membrane Polymer Films Frederic Pimet,+Eric Perez,? and Georges Belfort* Langmuir 1995,11, 1229-1235 1229 Molecular Interactions between Proteins and Synthetic Membrane Polymer Films Frederic Pimet,+Eric Perez,? and Georges Belfort* Howard P. Isermann Department of Chemical Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180-3590 Received August 27, 1993. In Final Form: December 5, 1994@ To help understand the effects of protein adsorption on membrane filtration performance, we have measured the molecular interactions between cellulose acetate films and two proteins with different properties (ribonucleaseA and human serum albumin) with a surface force apparatus. Comparison of forces between two protein layers with those between a protein layer and a cellulose acetate (CAI film shows that, at high pH, both proteins retained their native conformation on interacting with the CA film while at the isoelectric point (PI) or below the tertiary structure of proteins was disturbed. These measurements provide the first molecular evidence that disruption of protein tertiary structure could be responsiblefor the reduced permeation flows observed during membrane filtration of protein solutionsand suggest that operating at high pH values away from the PI of proteins will reduce such fouling. Introduction the solution-membrane interface.14-18 One of the most During the filtration of protein-containing solutions with studied model protein systems for understanding mem- pressure-driven membrane processes, the protein mol- brane polarization and fouling has been BSA solutions. ecules oRen adsorb onto and into the membranes. Besides For example, fluxes are higher when the pH is away from this adsorption process, exposure to fluid shear stresses the isoelectric point (PI) of the pr0tein,2~~~~J~J~when little can also denature the protein molecules rendering des- salt is present,1° and when the surface chemistry of the orption difficult if not impossible. Adsorption of protein membrane is hydr0phi1ic.l~ molecules in the membrane pores will affect the mean In order to help understand these effects, direct pore size and pore-size distribution available for the flow measurements of the intermolecular forces between and, hence, the permeation and retention characteristics selected model proteins, such as ribonuclease A (RNase of the membrane.’ A) and human serum albumin (HSA), and a widely used Much work has been reported on membrane filtration synthetic membrane material, cellulose acetate (CA),have with solutions containing macromolecules such as proteins been measured. ARer describing the procedures used with [bovine serum albumin (BSA), ovalbumin and lactoglo- the surface force apparatus, details are presented on the bulins], poly(viny1 alcohol),polyethylene glycol, dextrans, proteins and the celluloseacetate material. The properties and others. The decline of flux with time or total of CA films and those of two adsorbed HSA layers are first integrated volume permeated was initially explained as characterized by force measurements. Then, results membrane compaction. However, it soon became clear consisting of the direct measurements of the intermo- that different rates of flux decline occurred with different lecular forces between HSA and CA, and RNase A and CA solutions under similar experimental conditions. are presented. Several phenomena have been proposed to explain this. They include (1)protein adsorption, aggregation, and gel (8) Nabetani, H.; Nakajima, M.; Watanabe, A.; Nokao, S.; Kimura, formation, due to the effect of pH and ionic strength on S. Effects of osmotic pressure and adsorption on ultrafiltration of the solute-solute and solute-membrane interaction^,^-'^ ovalbumin AIChE J. 1990,36 (6), 907-915. (9) Blatt, W. F.; Dravid, A.; Michaels, A. S.; Nelson, L. Membrane and (2) reduced driving force caused by the effect of the Science & Technology; Flinn, J. E., Ed.; Industrial Biological Waste osmotic pressure due to the buildup of macromolecules at Treatment Processes; Plenum Press: New York, 1970. (10) Fane, A. G.; Fell, J. D.; Waters, A. G. Ultrafiltration of protein solutions through partially permeable membranes-the effect of adsorp- * Corresponding author. tion and solution environment J. Membr. Sci. 1983, 16, 211-224. Laboratoire de Physique Statistique, Ecole Normale Superieure, (11) Nakao, S.; Nomura, T.; Kimura, S.; Characteristics of macro- 24 rue Lhomond, 75005 Paris, France. molecular gel layer formed on ultrafiltration tubular membrane AIChE *Abstract published in Advance ACS Abstracts, February 15, J. 1979,25,615-622. 1995. (12) Nakao. S.;Kimura, S. Analysis of solutes rejection in ultrafil- (1) Belfort, G.; Pimbley, J. M.; Greiner pi.; Chung, K-Y. Diagnosis of tration J. Chem. Engr. Jpn 14 (1),-1981, 32-37. membrane fouling using a rotating annular filter. 1. Cell culture media. (13) Tirmizi, N. P., Study of UF of macromoleculars solutions Ph.D. J. Membr. Sci. 1993, 77, 1-22. thesis, Department of Chemical Engineering, RPI, Troy, NY, 1990. (2) Fane, A. G.; Fell, C. J.; Suzuki, A. The effect of pH and ionic (14) Goldsmith, R. L. Macromolecular ultrafiltration with mi- environment on the ultrafiltration of protein solutions with retentive croporous membranes Znd. Eng. Chem. Fundam. 1971,10,113-120. membranes J. Membr. Sci. 1983,16, 195-210. (15)Leung, W. F.; Probstein, R. F. Low polarization in laminar (3) Mattiasson, E. Role of macromolecular adsorption in fouling of ultrafiltration of macromolecular solutions Id.Eng. Chem. Fundam. ultrafiltration membranes J. Membr. Sci. 1983, 16, 23-36. 1979,18 (3), 274-278. (4) Nyst”, M., Laatikainen, M., Turku, M.; Jarvinen, P. Resistance (16) Viker, V. L.; Colton, C. K.; Smith, K. The osmotic pressure of to fouling accomplished by modification on ultrafiltration membranes concentrated protein solutions: effects of concentration and pH in saline Prog. Colloid Polym. Sei. 1990, 52, 321-329. solutions of bovine semm albumins J. Colloid Interface Sci. 1981, 79 (5) McDonogh, R. M.; Bauser, H.;Stroh, N.; Chmiel, H. Concentration (2), 548-566. polarization and adsorption effects in cross-flow ultrafiltration of proteins (17) Jonsson, G. Boundary layer ofphenomena duringultrafiltration Desalination 1990, 79, 217-231. of dextran and whey protein solutions Desalination 1984,51, 61-77. (6) Robertson, B. C.; Zydney, A. L. Protein adsorption in asymmetric (18) Wijmans, J. G.; Nakao, S.; Smolders, C. A. Flux limitation in ultrafiltration membranes with highly constricted pores J. Colloid ultrafiltration: osmotic pressure model and gel-layer model J. Membr. Interface Sci. 1990,134 (2), 563-575. Sci. 1984,20, 115-124. (7) Meireles, M.; Aimar, P.; Sanchez, V. Albumin denaturation during (19) Hannemaaijer, J. H.; Robertsen, T.; van der Boomgaard, Th.; ultrafiltration: effecta of operating conditions and consequences on Olieman, C.; Both, P.; Schmidt, D. G. Characterization of cleaned and membrane fouling Biotechnol. Bioengr. 1991,38,528-534. fouled ultrafiltration membranes Desalination 1988, 68, 93-108. 0743-746319512411-1229$09.00/0 0 1995 American Chemical Society 1230 Langmuir, Vol. 11, No. 4, 1995 Pincet et al. Materials and Methods Surface Force Apparatus (SFA). The technique involves the direct measurements of the intermolecular forces between 2.5 I two separate layers; one, an adsorbed protein layer, and the other, Y 1............... ............................ 1................... 1......' ........ .................. a film of cellulose acetate or adsorbed protein. Each layer is e hi deposited onto a smooth mica half-cylinder. The forces are 2 a obtained as a function of separation distance, which is measured ....................................... with an interferometry technique.20s21 It is the same method as 1 1.5 k that used to elucidate the intermolecularforces and conformation 1.5 -(d of adsorbed molecules between mica surfaces covered with ....... ...................... ...................... 8 surfactant,22-24 polymers,25-30 lipid mono- and bilayers,31-35 --+.) le -1 I proteins,36-@and glycolipids.44 The mica surfaces were immersed 2 E c4 (20)Israelachvili, J. N.; Adams, G. E. Measurementaofforcesbetween 3 0.5 0.5 \ two mica surfaces in aqueous electrolyte solutions in the range 1-100 0 5 10 15 20 25 nm J. Chem. SOC.Faraday Trans. 1 1978, 74,975-1001. (21)Israelachvili, J. N. Measurements of forces between surfaces Adsorption time, t (h) immersed in aqueous electrolyte solutions Faraday Discuss. Chem. Soc. 1978,65,20-24. Figure 1. Amount ofhydrated RNase A adsorbed and fractional (22)Israelachvili, J. N.;Pashley, R. M. The hydrophobic interaction surface coverage on mica as a function of time. The solution is long-range, decaying exponentially with distance Nature 1982,300, contained a RNase A concentration of 0.1 mg/mL in M 341 -343. KC1, pH 5, and at 20 f 0.5 "C. (23)Israelachvili, J. N.; Pashley, R. M. Measurement of the hydro- phobic interactions between two hydrophobic surfaces in aqueous solution J. Coll Intf. Sci 1984,98, 500-514. in aqueous electrolyte solution within a small Teflon bath. A (24)Pashley, R.M.; McGuiggan, P. M.; Ninham, B. W.; Evans, D. F. M KCl solution was used in all experiments unless otherwise Attractive forces between uncharged hydrophobic surfaces: direct stated. During each experiment, the KCl concentration and the measurements in aqueous solution Science 229, 1088-1089. pH value were kept constant. The pH value was, however, varied (25)Israelachvili, J. N.; Tirell, M.; Klein, J.; Almong, Y. Forces from one experiment to the next. A lo+ M KCl concentration between two layers of adsorbed polystyrene immersed
Load more

Recommended publications
  • Development of Polymeric Membranes for Oil/Water Separation
    membranes Article Development of Polymeric Membranes for Oil/Water Separation Arshad Hussain and Mohammed Al-Yaari * Chemical Engineering Department, King Faisal University, P.O. Box 380, Al-Ahsa 31982, Saudi Arabia; [email protected] * Correspondence: [email protected]; Tel.: +966-13-589-8583 Abstract: In this work, the treatment of oily wastewater was investigated using developed cellulose acetate (CA) membranes blended with Nylon 66. Membrane characterization and permeation results in terms of oil rejection and flux were compared with a commercial CA membrane. The solution casting method was used to fabricate membranes composed of CA and Nylon 66. Scanning Electron Microscopy (SEM) analysis was done to examine the surface morphology of the membrane as well as the influence of solvent on the overall structure of the developed membranes. Mechanical and thermal properties of developed blended membranes and a commercial membrane were examined by thermogravimetric analysis (TGA) and universal (tensile) testing machine (UTM). Membrane characterizations revealed that the thermal and mechanical properties of the fabricated blended membranes better than those of the commercial membrane. Membrane fluxes and rejection of oil as a function of Nylon 66 compositions and transmembrane pressure were measured. Experimental results revealed that the synthetic membrane (composed of 2% Nylon 66 and Dimethyl Sulfoxide (DMSO) as a solvent) gave a permeate flux of 33 L/m2h and an oil rejection of around 90%, whereas the commercial membrane showed a permeate flux of 22 L/m2h and an oil rejection of 70%. Keywords: oil–water separation; polymeric membrane; cellulose acetate; Nylon 66; permeability Citation: Hussain, A.; Al-Yaari, M.
    [Show full text]
  • Membrane Post Treatment
    America’s Authority in Membrane Treatment Membrane Post Treatment Post treatment for low pressure used for desalting drinking water determined by regulatory requirements, membranes (MF and UF) is typically supplies. the design of the system, finished water minimal consisting of disinfection (as a quality criteria and water chemistry. The MEMBRANE DESALINATION secondary barrier) and sometimes pH need for post-treatment generally de- PROCESSES adjustment and corrosion control, pends on a number of factors, which can Many municipal plants have multiple depending on raw water chemistry. be grouped into several categories, all of process trains installed in parallel, Since these low pressure membranes do which are related to water quality: allowing flexibility in permeate (product not remove dissolved substances and water) production and ease of • Chemical stability water chemistry remains unchanged, the expansion. In some instances it is post treatment approach is similar to • Microbiological Stability possible to bypass a portion of the raw conventional sand filtration and • Palatability and Customer or pretreated water around the therefore not discussed in this fact sheet. Acceptability membrane system and blend that flow Instead, this fact sheet focuses on with the permeate stream to reduce the • Secondary Impacts on membrane desalination. size of the membrane system, improve Wastewater Influent Quality Desalination is intended for the finished water stability, and minimize A recent overview of the current state of removal of total dissolved salts (TDS) capital and operating costs. The 62 full-scale RO/NF plants, 9 greater that generally cannot be removed by maximum allowable blend ratio is than one-million gallons per day of conventional treatment processes alone.
    [Show full text]
  • Evaluation of Membranes for Use in On-Line Cell Separation During Mammalian Cell Perfusion Processes
    CyWtechnology 15: 243-251, 1994. 243 c@ 1994 KluwerAcademic Publishers. Printedin the Netherlands. Evaluation of membranes for use in on-line cell separation during mammalian cell perfusion processes Heino Btintemeyer, Christoph Btihme and Jtirgen Lehmann Institute for Cell Culture Technology, University of Bielefeld, P.O. Box 100131, 33501 Bielefeld, Germany Key words: Hybridomate, monoclonal antibody, perfusion, microfiltration, membrane, fouling Abstract In this study two microporous hollow fibre membranes were evaluated for their use as cell retention device in continuous perfusion systems. A chemically modified permanent hydrophillic PTFE membrane and a hydrophilized PP membrane were tested. To investigate the filtration characteristic under process conditions each membrane was tested during a long term perfusion cultivation of a hybridoma cell line. In both cultivations the conditions influencing membrane filtration (e.g. transmembrane flux) were kept constant. Filtration behaviour was investigated by monitoring transmembrane pressure and protein permeability. Transmembrane pressure was measured on-line with an autoclavable piezo-resistive pressure sensor. Protein permeability was determined by quantitative evaluation of unreduced, Coomassie stained SDS-PAGE. The membrane fouling process influences the filtration characteristic of both membranes in a different way. After fermentation the PP membrane was blocked by a thick gel layer located in the big outer pores of the asymmetric membrane structure. The hydraulic resistance was higher but the protein permeability was slightly better than of the PTFE membrane. For this reason the PP membrane should be preferred. On the other hand, transmembrane pressure decreases slower when the PTFE membrane is used, which favours this membrane for long term cultivations, especially when low molecular weight proteins (<30 KD) are produced.
    [Show full text]
  • Fouling Prediction in Reverse Osmosis Processes 3
    Desalination,83(1991)3-33 ElsevierScience PublishersB.V..Amsterdam FOULING PREDICTION IN REVERSE OSMOSIS PROCESSES M. BARGER and R. P. CARNABAN Environmental and Water Resources Engineering, University of Michigan, Ann Arbor, Michigan and Civil Engineering, University of South Florida, Tampa, Florida INTRODUCTION In recent years, membrane separation processes have successfully established footholds in all areas of chemical separations. Semipermeable membranes are now enhancing and even replacing long-time standard techniques such as distillation and solvent extraction (1). They are also being used in the preparation of purified chemical and biological products as well as the treatment and recovery of many industrial waste streams (2, 3). Many of these recent technological advances follow from successful research begun in the 1950's to desalinate seawater using synthetic membranes in reverse osmosis processes. While other methods to desalinate seawater have proven too unreliable or too expensive, the use of reverse osmosis in the production of potable water has steadily increased (4). Despite its growing popularity and improved technology, reverse osmosis, RO, along with all membrane separation processes continues to be plagued with one persistent problem. The problem is membrane fouling (5). Eyecamp has defined this broad term as the following: "Fouling is a condition in which a membrane undergoes plugging or coating by some element in the stream being treated, in such a way that its output or flux is reduced and in such a way that the foulant is not in 3 dynamic equilibrium with the stream being ultrafiltered. In other words, something has occurred that makes the micro-environment near the membrane a nonsteady state situation." (6) The fouling phenomenon adversely effects both the quantity and quality of the product water; the two characteristics that must be maximized for the most efficient and economical use of the process.
    [Show full text]
  • New Insights Into the Application of Microbial Desalination Cells for Desalination and Bioelectricity Generation
    Biofuel Research Journal 24 (2019) 1090-1099 Journal homepage: www.biofueljournal.com Original Research Paper New insights into the application of microbial desalination cells for desalination and bioelectricity generation Halima Alhimali1, Tahereh Jafary1, Abdullah Al-Mamun1,*, Mahad Said Baawain1, G. Reza Vakili-Nezhaad2 1 Department of Civil and Architectural Engineering, Sultan Qaboos University, P.O. Box 33, Al-Khoud, 123, Muscat, Sultanate of Oman. 2Department of Petroleum and Chemical Engineering, Sultan Qaboos University, P.O. Box 33, Al-Khoud, 123, Muscat, Sultanate of Oman. HIGHLIGHTS GRAPHICAL ABSTRACT Ion behavior of three different salt solutions was studied in identical microbial desalination cells (MDCs). 2+ 2+ 3- Mg , Ca , and PO4 were major ions resulting in scaling on cation exchange membrane. Inorganic deposition and biofouling were more dominant on anion exchange membrane. Back diffusion of K+ from catholyte to liquid under desalination reduced MDC performance. Increasing bioelectricity generation will boost the rate of ions transportation. ARTICLE INFO ABSTRACT Article history: Microbial desalination cell (MDC) is considered as a cost-effective substitution to the present energy-intensive desalination Received 25 October 2019 methods. Transfer of salt ions through ion exchange membranes towards the counter electrodes takes place through the Received in revised form 20 November 2019 utilization of self-generated bioelectricity and the concentration gradient. Ions transportation is one of the main challenges faced Accepted 22 November 2019 in MDCs to which less attention has been paid during the course of development. Therefore, new insights into the application Available online 1 December 2019 of MDCs for efficient utilization of the generated bioelectricity for desalination are of high demand.
    [Show full text]
  • Transport Phenomena Through Polymeric Systems
    Prog. Polym. Sci. 26 72001) 985±1017 www.elsevier.com/locate/ppolysci Transport phenomena through polymeric systems Soney C. George1, Sabu Thomas* School of Chemical Sciences, Mahatma Gandhi University, Priyadarshini Hills P.O., Kottayam 686560, Kerala, India Received 3 December 1999;accepted 28 July 2000 Abstract Transport of gases, vapours and liquids through polymers is an important and in some cases, controlling factor in several applications such as protective coatings, membrane separation processes and packaging of foods and beverages. Therefore a better understanding of transport mechanisms in polymers is highly important in order to achieve signi®cant improvement in these areas. This article provides a detailed review of current research in the ®eld of transport phenomena and membrane assisted transport processes. Topics covered include the factors affecting transport processes and transport in various polymeric systems. The relationships between membrane characteristics, polymer structure and separation ef®cacy are treated in detail. q 2001 Elsevier Science Ltd. All rights reserved. Keywords: Transport;Permeation;Pervaporation;Vapour permeation;Gas permeation;Polymer;Polymer blend;Membranes Contents 1. Introduction .................................................................. 986 2. Fundamentals of transport phenomena ............................................... 986 3. Factors contributing to transport processes ............................................ 988 3.1. Nature of the polymer ......................................................
    [Show full text]
  • Diffusion Properties of Different Compounds Across Various Synthetic Membranes Using Franz-Type Diffusion Cells
    See discussions, stats, and author profiles for this publication at: https://www.researchgate.net/publication/257808546 Diffusion properties of different compounds across various synthetic membranes using Franz-type diffusion cells Article in Journal of Pharmaceutical Investigation · October 2012 DOI: 10.1007/s40005-012-0040-5 CITATIONS READS 6 707 5 authors, including: Younjung Jung NaeGyu Kang Hanmi Pharmaceutical LG Households & Health Care Ltd, Seoul, Korea 2 PUBLICATIONS 14 CITATIONS 30 PUBLICATIONS 121 CITATIONS SEE PROFILE SEE PROFILE All content following this page was uploaded by Younjung Jung on 16 August 2015. The user has requested enhancement of the downloaded file. Journal of Pharmaceutical Investigation (2012) 42:271–277 DOI 10.1007/s40005-012-0040-5 RESEARCH ARTICLE Diffusion properties of different compounds across various synthetic membranes using Franz-type diffusion cells Youn Jung Jung • Jeong-Hyun Yoon • Nae Gyu Kang • Sun Gyoo Park • Seong Hoon Jeong Received: 22 July 2012 / Accepted: 10 September 2012 / Published online: 8 October 2012 Ó The Korean Society of Pharmaceutical Sciences and Technology 2012 Abstract Diffusion properties of typical functional cos- Introduction metic ingredients, niacinamide, ascorbic acid 2-glucoside, retinol and polyethoxylated retinamide, were evaluated When an active ingredient is applied topically as oint- across various synthetic membranes using Franz-type dif- ments or cosmetics, it must be released from the vehicle fusion cells. Different kinds of artificial membranes before it reaches the epidermal surface and be available available in the market were utilized for comparing how for penetration into the stratum corneum and hence lower the functional ingredients diffuse through the membrane. layers of the skin (Shah et al.
    [Show full text]
  • JL-(Oo Hli"(Vis) Or L1 Cjcen')--D Has Been Studied by the Introduction of a Carrier to CH 2 I Promote Its Capability for These Functions
    Polymer Journal, Vol. 15, No. 2, pp 135-138 (1983) Polymer Membranes as a Reaction Field I. A Characterization of Environment of Polymer Takeo SHIMIDZU* and Masakazu YOSHIKAWA Department of Hydrocarbon Chemistry, Faculty of Engineering, Kyoto University, Kyoto 606, Japan (Received August 31, 1982) ABSTRACT: The environment of a polymer field as a solid medium could be evaluated using a spiropyran compound as an indicator. This method provides a useful means for an accurate determination of polymer character. KEY WORDS Synthetic Polymer Membrane I Polymer Reaction Field I Spiropyran Derivative I Photochromism I Dimroth's Solvent Polarity Value I Characterization of Polymer I Hitherto synthetic polymer membranes have been used as barriers for separating two phases and media for selective separation. Recently, the latter NO, Y :h l-::JL-(oO hli"(Vis) or L1 CJCeN')--D has been studied by the introduction of a carrier to CH 2 I promote its capability for these functions. Synthetic 1 (CH 2 )16 I polymer membranes having chemical functional 1 (CH,),G CH 3 I groups function as selective separation membranes. CH 3 The active and sel<:<ctive transport of metal ions with 1 2 synthetic membranes such as a lactone-containing A plot of the wavelength of the absorption max­ polymer membrane was demonstrated for the first imum of the chromophore, 2, formed by the ring­ time. 1 - 5 Up to now, anion transport membranes opening of 1 in various solution in the visible range have been developed by Ogata and his coworkers.6 vs. Dimroth's solvent polarity value (ET The synthetic membrane can also be used to (25°C)) gave a straight line.
    [Show full text]
  • Interaction-Based Ion Selectivity Exhibited by Self-Assembled, Cross-Linked Zwitterionic SPECIAL FEATURE Copolymer Membranes
    Interaction-based ion selectivity exhibited by self-assembled, cross-linked zwitterionic SPECIAL FEATURE copolymer membranes Samuel J. Loundera and Ayse Asatekina,1 aDepartment of Chemical and Biological Engineering, Tufts University, Medford, MA 02155 Edited by Howard A Stone, Princeton University, Princeton, NJ, and approved May 18, 2021 (received for review January 4, 2021) Water filtration membranes with advanced ion selectivity are assemblies (10), carbon nanotubes (11, 12), and graphene oxide urgently needed for resource recovery and the production of clean laminates (13). These various approaches face severe manufacturing drinking water. This work investigates the separation capabilities challenges (6, 14), however, and the use of polymeric materials is of cross-linked zwitterionic copolymer membranes, a self-assembled preferrable due to low cost and simple scale-up (6). For example, membrane system featuring subnanometer zwitterionic nanochan- block copolymers (BCPs) have been used to fabricate ultrafiltration nels. We demonstrate that selective zwitterion–anion interactions (UF) membranes with controlled pore wall functionality (15), simultaneously control salt partitioning and diffusivity, with the per- leading to tunable selectivity through solute–membrane interactions meabilities of NaClO4, NaI, NaBr, NaCl, NaF, and Na2SO4 spanning (16, 17). However, the relatively large size of BCP membrane pores roughly three orders of magnitude over a wide range of feed con- (>2 to 3 nm) limits its use for ion separations. Membranes formed centrations. We model salt flux using a one-dimensional transport from packed arrays of random copolymer micelles have demon- model based on the Maxwell–Stefan equations and show that diffu- strated selectivity based on solute charge (9) and aromaticity (18), sion is the dominant mode of transport for 1:1 sodium salts.
    [Show full text]
  • Highlights Article Info Graphical Abstract
    Journal of Membrane Science and Research 2 (2016) 118-127 Journal of Membrane Science & Research journal homepage: www.msrjournal.com Research Paper Monopolar and Platinum Interfaced Bipolar Membrane Electrodialysis: Experimental Assessment Using Synthetic Salt Solution Heterogeneous Cation Exchange Membranes Krishnaveni Venugopal, Sangeetha Dharmalingam* Department of Mechanical Engineering, Anna University, Guindy Chennai 600025, Tamil Nadu, India ARTICLE INFO GRAPHICAL ABSTRACT Received 2015-06-25 Revised 2015-07-20 Accepted 2015-07-21 Available online 2015-07-21 KEYWORDS Current efficiency Desalination Water splitting Platinum intermediate Reproducibility HIGHLIGHTS • Reinforced monopolar and bipolar IEM preparation using functionalized PSEBS polymer • Effect of platinum metal in BPM interface on water splitting was analyzed • Synthetic NaCl solution of brackish water range was used • Reproducibility of the membranes in BPMED performance was checked ABSTRACT In this study, polystyrene ethylene butylene polystyrene (PSEBS) was functionalized to prepare mono and bipolar ion exchange membranes. In the case of the bipolar membrane, platinum was used as the intermediate layer. NaCl solution of concentration ranging from 5 g/L to 25 g/L was used as the feed solution. A commercially procured ion exchange membrane made of polystyrene divinyl benzene was also evaluated for the purpose of comparison. The BPMED performance reached the highest current efficiency of 69.54% and 53.6% with the energy consumption of 0.37 Wh and 1.39 Wh for the synthesized and commercial membranes, respectively. Also the performance of the fabricated unit was assessed in terms of electrical conductivity, salinity and ion (sodium and chloride) concentrations for the feed solution after 8-hour duration. The reproducibility performance of the membranes was also analyzed for the synthetic salt solution.
    [Show full text]
  • Axter-Ecoflex-Single-Ply-PVC-System-Brochure-Feb-2014.Pdf
    03 CI/SfB (47) E February 2014 f ECOFLEX SINGLE-PLY ROOFING ECOFLEX SINGLE-PLY ROOFING AXTER ECOFLEX Axter is part of the Bouygues Group of Companies Engineered to provide unrivalled environmental and is one of the world’s leading designers and performance, ECOFLEX is a lightweight, flexible manufacturers of roofing and waterproofing PVC-p single-ply synthetic membrane that membranes. With over 100 years of experience, has been specifically designed for widespread Axter specialises in the production of high quality, use on all roofing projects including domestic, robust, fully integrated membranes for extensive commercial and industrial structures. ECOFLEX use in both new build and renovation projects. systems provide excellent performance characteristics such as strength and flexibility and Axter’s comprehensive product portfolio includes are fully reinforced and available with or without a over 700 different systems which have been fleece back (ADH material); this determines the engineered to provide unparalleled performance product application. The ECOFLEX system is and design flexibility. Through our global network complemented with a full range of vapour control of dedicated representatives and our relentless layers and accessories that ensure a total design commitment to research and development, Axter and installed solution is achieved. ensures its systems are successfully supplied and installed in more than 60 countries worldwide. ECOFLEX systems deliver specifier and installer confidence in both performance and design It is Axter’s proud tradition in the design and freedom. The waterproofing membranes can manufacture of high performance waterproofing be installed either mechanically fixed (FM) or systems that has facilitated the development of adhered (ADH) as part of a warm roof installation.
    [Show full text]
  • State of the Art Roofing Systems: PVC Membrane Roofing -- a New Approach”
    “State of the art roofing systems: PVC membrane roofing -- a new approach” Key words: roofing, synthetic membrane, PVC, single ply roofing, thermoplastic. Abstract: Construction industry in India has been at its all time high growth rate for past couple of years. The growth is in all walks of construction world, be it infrastructure, industrial or residential. This exponential growth has also thrown a few challenges at the construction professionals all across India which has motivated them to look at newer approaches to tackle such challenges. Waterproofing (including roofing) has seen two distinct changes in approaches in the recent times: # New technologies (Design driven) # New concepts (Construction driven) Introduction of synthetic membrane roofing systems in India is one such step forward towards this new approach in terms of technology and concept. With a high end, state of the art technology like PVC membrane based waterproofing and roofing systems, there can be serious value additions where conventional systems found to be less equipped to handle the higher demands like in the following typical applications; • case of re roofing of old bituminous and tiled roofs, • metal deck applications, • roof gardens, • energy savings in buildings and green building requirements (LEED certified) from roofing materials In short, this means that this state of the art technology now provides the construction world with a solution which has evolved by taking care of such requirements and hence can be looked at as an option when conventional treatments give lesser performance. Author biography: Arijit Basu is a marketing professional with more than 13 years of cross functional experience in the field of construction chemicals in Indian market.
    [Show full text]