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 29

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.
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.
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
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.
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.
Salt diffusion through cation-exchange membranes in alcohol-water solutions
(Separation and Purification Technology, 2009) Izquierdo Gil, María Amparo; Barragán García, Vicenta María; Godino Gómez, María Paz; García Villaluenga, Juan Pedro; Ruiz Bauzá, Carlos; Seoane Rodríguez, Benjamín
The salt flow through several commercial cation-exchange membranes separating two NaCl alcohol-water solutions with the same alcohol concentration, but different NaCl concentration was investigated. Homogeneous (Nafion-115) and heterogeneous (MK-40 and CR65-AZL-412) membranes were used in this work. The integral permeability coefficient was determined from the temporal evolution of the concentration in the dilute solution. The results showed that the integral permeability coefficient depends on both the solution alcohol concentration and the type of alcohol. It is observed that this dependence is function of the membrane structure. In general, for the heterogeneous membranes, the integral permeability coefficient is less sensible to alcohol concentration than for the homogeneous membrane at low and intermediate values of the alcohol percentage in the solutions.
Gas permeation characteristics of heterogeneous ODPA-BIS P polyimide membranes at different temperatures
(Journal of Membrane Science, 2007) García Villaluenga, Juan Pedro; Seoane Rodríguez, Benjamín; Hradil, J.; Sysel, P.
Heterogeneous carbon molecular sieves and hypercrosslinked polystyrene microparticles adsorbent-based membranes with a (ODPA-BIS P) polyimide binder were prepared. The effect of adsorbent particles on the gas transport properties of heterogeneous membranes was studied. Permeability, diffusion and solubility coefficients of He, CO2, O-2 and N-2 were estimated for homogeneous and heterogeneous membranes at a feed pressure of 1 atm for different temperatures between 25 and 60 degrees C. It was observed that adsorbent-filled (ODPA-BIS P) polyimide membranes exhibit higher gas permeability in comparison with adsorbent-free membrane, while permselectivity is maintained. The results also showed that the adsorbents enhance significantly gas diffusivity in (ODPA-BIS P) polyimide membrane, whereas the gas solubility is clearly reduced. In both type of heterogeneous membranes, gas permeation and diffusion are thermal activated processes described by the Arrhenius equation, whereas the Sorption process is exothermic. The addition of both type of adsorbents to the (ODPA-BIS P) polyimide membrane increases the activation energy of permeability, this is mainly due to a significant increase of the heat of sorption, because the activation energy for diffusion is slightly decreased.
Simultaneous electroosmotic and permeation flows through a Nafion membrane - 2. Methanol-water electrolyte solutions
(Journal of Colloid and Interface Science, 2005) Barragán García, Vicenta María; Ruiz Bauzá, Carlos; García Villaluenga, Juan Pedro; Seoane Rodríguez, Benjamín
The volume flow of methanol-water potassium chloride solutions through a Nation membrane originated by the simultaneous action of electric potential and pressure gradients has been measured at different percentage, of methanol. Measurement were conducted when both gradients act in the same and in the opposite directions under different experimental conditions. The result, indicate that the simultaneous action of the pressure and potential differences originates a total flow different from the sum of the individual electroosmotic and permeation flows due to each force acting separately. The application of the irreversible thermodynamics theory, which includes second-order terms, allowed the study of the influence of the composition of the solutions on the determination of the different phenomenological coefficients.