Person:
Seoane Rodríguez, Benjamín

First Name

Benjamín

Last Name

Seoane Rodríguez

URI

https://hdl.handle.net/20.500.14352/84030

Affiliation

Universidad Complutense de Madrid

Faculty / Institute

Ciencias Físicas

Area

Física Aplicada

Identifiers

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Now showing 1 - 10 of 28

Water and methanol transport in Nafion membranes with different cationic forms 1. Alkali monovalent cations
(Journal of Power Sources, 2006) Godino Gómez, María Paz; Barragán García, Vicenta María; García Villaluenga, Juan Pedro; Ruiz Bauzá, Carlos; Seoane Rodríguez, Benjamín
The mass flux originated when two methanol-water solutions of different methanol concentration are separated by a Nation 117 membrane in acid (H+) and different alkali metal forms (Li+, Na+, K+, Rb+, Cs+) have been measured, as a function of the methanol concentration difference. From the experimental results, the methanol and water permeabilities have been estimated for the different forms of the membrane. The results show that the cationic form of the membrane strongly influences on the methanol and water permeabilities with respect to the values corresponding to its acid form. Moreover, this influence is different for water and methanol depending on the substituted cation. This strong influence of the cationic form of the membrane on the methanol and water permeabilities could be important in relation to the development of new membranes to decrease the methanol crossover in direct methanol fuel cells.
Pervaporation of toluene/alcohol mixtures through a coextruded linear low-density polyethylene membrane
(Industrial and engineering chemistry research, 2003) García Villaluenga, Juan Pedro; Khayet Souhaimi, Mohamed; Godino Gómez, María Paz; Seoane Rodríguez, Benjamín; Mengual Cabezón, Juan Ignacio
The pervaporation characteristics of toluene/methanol, toluene/ethanol, and toluene/propanol mixtures through a linear low-density polyethylene membrane were investigated at different feed compositions. These characteristics were obtained from quantities such as the swelling ratio, permeation rate, and selectivity. In all cases toluene permeates preferentially through the membrane, with a separation factor up to 66 and fluxes varying between 0.1 and 1.4 kg/ m2.h. Predictions based on the Flory-Huggins theory have shown that toluene is preferentially sorbed by the membrane. The pervaporation flux increases and the selectivity decreases with the toluene content in the feed. The experimental results show that pure-alcohol fluxes decrease with the molecular size.
Study of the activation energy for transport of water and methanol through a Nafion membrane
(Chemical Engineering Journal, 2009) Godino Gómez, María Paz; Barragán García, Vicenta María; García Villaluenga, Juan Pedro; Izquierdo Gil, María Amparo; Seoane Rodríguez, Benjamín; Ruiz Bauzá, Carlos
This study investigates the influence of different operating parameters in the transport of water and methanol through a Nafion membrane when it is used to separatewater fromamethanol–water solution. For this purpose, measurements of mass flux and concentration change have been performed at different values of circulation velocity, concentration of themethanol–water solutions and temperature conditions. From the experimental data, thewater and methanol partial fluxes have been estimated, and itwas found that the water flux is always lower than the methanol flux, but it cannot be neglected. Whereas total and methanol fluxes seem to have predictable and similar behaviors, the water flux seems to be less predictable and it exhibits a very distinct behavior. Methanol and water permeabilities have been calculated, and from these values the activation energy of methanol and water fluxes in the membrane has been estimated. The results have been discussed in terms of the methanol and water solubilities in the membrane.
Permeation of carbon dioxide through multiple linear low-density polyethylene films
(European polymer journal, 2000) García Villaluenga, Juan Pedro; Seoane Rodríguez, Benjamín
We have investigated the effect of stacking on the permeation of carbon dioxide through multilayer LLDPE films. The measurements were carried out using samples made up of one, two, four, eight and 12 films, respectively, over the temperature interval of 25-85 degrees C. The results indicate that the permeability coefficient P of carbon dioxide does not show any variation on the number of films stacked. In contrast, the time lag values increase in a non-linear way with increasing the number of films in the samples. The analysis of these results, according to gas permeation models through multilayer systems, shows that boundary effects at the interface between films are not found, on the one hand, and the experimental values determined for the time lags are in good agreement with the theoretical predictions, on the other hand.
Fluid flow modeling in a sulfonated cation-exchange membrane
(Journal of Applied Polymer Science, 2009) García Villaluenga, Juan Pedro; Barragán García, Vicenta María; Izquierdo Gil, María Amparo; Godino Gómez, María Paz; Seoane Rodríguez, Benjamín; Ruiz Bauzá, Carlos
Liquid permeation measurements of water, methanol, and 2-propanol were carried out using a commercial cation-exchange membrane Nafion-117 (perfluorinated polyethylene with pendant ether-linked side chains terminated with sulfonated groups). The experimental permeation data are treated and analyzed using the capillary model, leading to the determination of equivalent pore radius of the membrane structure.
Experimental estimation of equilibrium and transport properties of sulfonated cation-exchange membranes with different morphologies
(Journal of Colloid and Interface Science, 2009) Barragán García, Vicenta María; García Villaluenga, Juan Pedro; Godino Gómez, María Paz; Izquierdo Gil, María Amparo; Ruiz Bauzá, Carlos; Seoane Rodríguez, Benjamín
Solvent uptake, hydraulic and electroosmotic permeabilities, true cation transport number, effective fixed charge concentration, and limiting current values have been determined in aqueous LiCl solutions for three commercial cation-exchange membranes with different morphologies and similar electric properties. The differences found in the equilibrium and transport properties of the membranes have been analyzed on the basis of their different structures. The experimental results show that the membrane morphology has an influence on the effect that the presence of an electrolyte has in the solvent uptake and in the liquid permeation. Differences have also been found in the polarization concentration effects, and on the loss of the membrane selectivity with the increase of the electrolyte concentration.
Simultaneous electroosmotic and permeation flows through a Nafion membrane - 1. Aqueous electrolyte solutions
(Journal of Colloid and Interface Science, 2004) Barragán García, Vicenta María; Ruiz Bauzá, Carlos; García Villaluenga, Juan Pedro; Seoane Rodríguez, Benjamín
The volume flow through a Nafion membrane originated by the simultaneous action of an electric potential difference and a pressure difference has been measured using aqueous KCl solutions under different experimental conditions. The behavior has been analyzed when both gradients act in the same and in the opposite sense. The results indicate that the simultaneous action of the pressure and potential differences originates a total flow different from the sum of the electroosmotic and permeation flows due to each force acting separately. The application of irreversible thermodynamics, which includes second-order terms, allowed the determination of the phenomenological coefficients. Moreover, from these values, the equivalent pore radius was estimated on the assumption that the membrane is a porous medium filled with an internal solution.
Poly(2,6-dimethyl-1,4-phenylene oxide) mixed matrix pervaporation membranes
(Desalination, 2006) Khayet Souhaimi, Mohamed; García Villaluenga, Juan Pedro; Valentín, Juan L.; López Manchado, Miguel Ángel; Mengual Cabezón, Juan Ignacio; Seoane Rodríguez, Benjamín
Preparation and application of dense poly(phenylene oxide) membranes in pervaporation
(Journal of colloid and interface science, 2004) Khayet Souhaimi, Mohamed; García Villaluenga, Juan Pedro; Godino Gómez, María Paz; Mengual Cabezón, Juan Ignacio; Seoane Rodríguez, Benjamín; Khulbe, K. C.; Matsuura, T.
Dense flat-sheet membranes were prepared from poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) using the casting solvents chloroform and 1,1,2-trichloroethylene. X-ray diffraction, tapping mode atomic force microscopy (TM-AFM), and contact angle studies were used to characterize the membranes. The surface energy and the solubility parameters of the PPO membranes were determined from the measured contact angles and compared with the predicted ones from the group contribution method. Swelling experiments and pervaporation separation of methanol from its mixture with ethylene glycol over the entire range of concentration, 0-100%, were conducted using these membranes. Flory-Huggins theory was used to predict the sorption selectivity. The results are discussed in terms of the solubility parameter approach and as function of the morphological characteristics of the membranes. It was found that PPO membranes prepared with chloroform exhibited better pervaporation performance than PPO membranes prepared with 1, 1,2-trichloroethylene.
On the methanol-water electroosmotic transport in a Nafion membrane
(Journal of Membrane Science, 2004) Barragán García, Vicenta María; Ruiz Bauzá, Carlos; García Villaluenga, Juan Pedro; Seoane Rodríguez, Benjamín
Electroosmosis experiments through a Nafion membrane have been performed using methanol–water KCl solutions in different experimental situations. The influence on the electroosmotic transport of the percentage of methanol on solvent at different electrolyte concentrations has been studied. The experimental results show that the presence of methanol on the solutions affects strongly to the electroosmotic flow. From the current–voltage curves determined for this membrane system, the limiting currents were obtained at different volume percentages of methanol. The values obtained decrease with increasing the percentage of methanol and a minimum value seems to be reached at certain percentage of alcohol.