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Synthesis and modeling of charged ultrafiltration membranes of poly(styrene-co-divinyl benzene) for the separation of chromium(VI) / Sonny Sachdeva in Industrial & engineering chemistry research, Vol. 47 n°12 (Juin 2008) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 47 n°12 (Juin 2008) . - p. 4236–4250 Titre : Synthesis and modeling of charged ultrafiltration membranes of poly(styrene-co-divinyl benzene) for the separation of chromium(VI) Type de document : texte imprimé Auteurs : Sonny Sachdeva, Auteur ; Anil Kumar, Auteur Année de publication : 2008 Article en page(s) : p. 4236–4250 Note générale : Bibliogr. p. 4249-4250 Langues : Anglais (eng) Mots-clés : Polystyrene  composite  membrane;  Gas-phase  nitration;  Amination;  Quaternization;  Chromium(VI) Résumé : A ceramic supported cross-linked polystyrene (PS) composite membrane has been prepared from its monomers using a dual initiator system, and it has been chemically modified by gas-phase nitration (using NOx), amination using hydrazine hydrate, and quaternization using dichloroethane and triethylamine. The membranes (unmodified, aminated, and quaternized) have been used to study the rejection of chromium(VI) as a function of pressure, concentration, and pH of the feed solution, which was observed to be >90%. The experimental results have been fitted using a space charge model (SCM) to obtain the membrane wall potential and membrane surface concentration. The transport through the membrane capillaries has been described by a two-dimensional model, using the Nernst−Planck equation for ion transport, the Navier−Stokes equation to describe the flow, and the Poisson−Boltzmann equation for the radial distribution of potential. A semianalytical series solution to the highly nonlinear Poisson−Boltzmann equation has been developed, to reduce the computational time required to solve the set of coupled differential equations. The effective wall potential was determined to be 85.95 and 78.7 mV for the quaternized and aminated membranes, respectively. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie070730g [article] Synthesis and modeling of charged ultrafiltration membranes of poly(styrene-co-divinyl benzene) for the separation of chromium(VI) [texte imprimé] / Sonny Sachdeva, Auteur ; Anil Kumar, Auteur . - 2008 . - p. 4236–4250. Bibliogr. p. 4249-4250 Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 n°12 (Juin 2008) . - p. 4236–4250 Mots-clés : Polystyrene  composite  membrane;  Gas-phase  nitration;  Amination;  Quaternization;  Chromium(VI) Résumé : A ceramic supported cross-linked polystyrene (PS) composite membrane has been prepared from its monomers using a dual initiator system, and it has been chemically modified by gas-phase nitration (using NOx), amination using hydrazine hydrate, and quaternization using dichloroethane and triethylamine. The membranes (unmodified, aminated, and quaternized) have been used to study the rejection of chromium(VI) as a function of pressure, concentration, and pH of the feed solution, which was observed to be >90%. The experimental results have been fitted using a space charge model (SCM) to obtain the membrane wall potential and membrane surface concentration. The transport through the membrane capillaries has been described by a two-dimensional model, using the Nernst−Planck equation for ion transport, the Navier−Stokes equation to describe the flow, and the Poisson−Boltzmann equation for the radial distribution of potential. A semianalytical series solution to the highly nonlinear Poisson−Boltzmann equation has been developed, to reduce the computational time required to solve the set of coupled differential equations. The effective wall potential was determined to be 85.95 and 78.7 mV for the quaternized and aminated membranes, respectively. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie070730g