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Author (up) Buekenhoudt, A.; Bisignano, F.; De Luca, G.; Vandezande, P.; Wouters, M.; Verhulst, K.
Title Unravelling the solvent flux behaviour of ceramic nanofiltration and ultrafiltration membranes Type A1 Journal article
Year 2013 Publication Journal of membrane science Abbreviated Journal J Membrane Sci
Volume 439 Issue Pages 36-47
Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT); Applied Electrochemistry & Catalysis (ELCAT)
Abstract In order to increase the understanding of the underlying processes in organic solvent nanofiltration (OSN), a study has been undertaken aimed at clarifying the solvent flux behaviour of ceramic nanofiltration and ultrafiltration membranes. Ceramic membranes were chosen for their non-swelling character. Pure water and a variation of 11 different organic solvents were measured on a series of different ceramic membranes with pore-size diameters ranging from 0.9 nm up to 100 nm. To avoid any historical effects, each flux measurement was carried out on a new membrane. The flux results were analysed in a phenomenological way, and a common very simple linear relationship was observed between the product of flux and viscosity of the solvent, and the total Hansen solubility parameter of the solvent. The linear relationship was found for all membranes, independent of the membrane pore size and the membrane material. The slope of the linear relationship was found to depend exponentially on the pore-size diameter and on the polarity of the membrane surface. This result emphasizes the importance of viscosity in the solvent transport, but also of the polarity difference between membrane surface and solvent. The very simple flux model deduced, allows a straightforward prediction of the flux of any solvent or solvent mixture, once the water flux of the membrane is known. At the high pore-size end, the phenomenological model naturally transforms into the viscous-flow or pore-flow behaviour as required. A tentative physical explanation of the model takes into account the presence and extension of a water layer adsorbed to the total pore surface of these membranes. This work also shows that the water flux of a hydrophilic membrane gives a good indication of its molecular weight cut-off (MWCO), and therefore of its separation performance in water. (C)0 2013 Elsevier B.V. All rights reserved.
Address
Corporate Author Thesis
Publisher Place of Publication Amsterdam Editor
Language Wos 000319501200005 Publication Date 2013-03-30
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0376-7388; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.035 Times cited 55 Open Access
Notes Approved Most recent IF: 6.035; 2013 IF: 4.908
Call Number UA @ lucian @ c:irua:109568 Serial 3816
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Author (up) Pauwels, D.; Hereijgers, J.; Verhulst, K.; De Wael, K.; Breugelmans, T.
Title Investigation of the electrosynthetic pathway of the aldol condensation of acetone Type A1 Journal article
Year 2016 Publication Chemical engineering journal Abbreviated Journal Chem Eng J
Volume 289 Issue Pages 554-561
Keywords A1 Journal article; Engineering sciences. Technology; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Applied Electrochemistry & Catalysis (ELCAT)
Abstract The potential-controlled electrochemical aldol condensation of acetone to diacetone alcohol in a standard batch electrolysis set-up was studied in this work. It is confirmed that the reaction proceeds at the cathode and that, contrary to what is mentioned in earlier literature, water in the electrolyte has a disadvantageous effect on the reaction. Similar to the chemical reaction, the electrochemical reaction reaches a maximum yield when the equilibrium is reached. Separating the anode and cathode prevents cross-over and degradation of products, leading to a higher yield. Starting with pure acetone and support electrolyte, it was possible to obtain a diacetone alcohol concentration of 15 m% after two hours electrolysis in a divided set-up with a platinum electrode at -2.5 V. The concentration gradient throughout the electrolysis follows an exponential curve up to its equilibrium concentration.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000371559900061 Publication Date 2016-01-13
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1385-8947; 1873-3212 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.216 Times cited 6 Open Access
Notes ; ; Approved Most recent IF: 6.216
Call Number UA @ admin @ c:irua:130396 Serial 5675
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