Porosity measurements by a gas penetration method and other techniques applied to membrane characterization

Palacio, Laura; Prádanos, Pedro; Calvo, José Ignacio Madalena; Hernández, Antonio

doi:10.1016/s0040-6090(99)00197-2

Cited by 94 publications

(58 citation statements)

References 25 publications

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“…Se observa nuevamente un acuerdo razonable con los valores nominales propuestos por el fabricante, aunque en algunos casos las desviaciones son importantes, especialmente respecto a los datos de porosidad. Estos valores de la porosidad se han comparado con los procedentes de diversas técnicas de caracterización, (7,9,10). Los resultados de dicha comparación se presentan en la Figura 4, para un conjunto representativo de las membranas analizadas.…”

Section: Resultsunclassified

“…I. CALVO, L. PALACIO, P. PRÁDANOS, A. MARTíN, F. MARTíNEZ y A. HERNÁNDEZ Los datos obtenidos del análisis de las imágenes de AFM fueron comparados con resultados provenientes de otras téc-nicas de caracterización habituales en el análisis de membranas y materiales porosos en general. Así se utilizó un equipo de adsorción-desorción de gases (con permeación de helio), un Omnisorp 100-CX de Coulter Ltd., para determinar la porosidad de las membranas mediante una técnica desarrollada en este grupo, (7).…”

Section: Equipos Y Técnicas Experimentalesunclassified

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Estudio estructural de membranas cyclopore de microfiltración

Calvo¹,

Palacio²,

Prádanos³

et al. 2000

Bol. Soc. Esp. Ceram. Vidr.

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La Microscopía de Fuerza Atómica (AFM), de reciente desarrollo, se ha revelado como una técnica especialmente valiosa en la caracterización de todo tipo de superficies y materiales. En este trabajo se ha utilizado dicha técnica en la caracterización superficial de diversos filtros de microfiltración, obtenidos por el método de revelado de trazas nucleares, y en consecuencia, especialmente útiles como membranas test, debido a su simple estructura. Para estas membranas se han estudiado diversos parámetros de interés estructural, como son la porosidad, la distribución de tamaños de poro y la rugosidad superficial de las mismas. Todos estos parámetros han sido convenientemente analizados y sus resultados comparados con los obtenidos por otras técnicas de caracterización complementarias, a fin de asegurar su validez y fiabilidad. Se ha obtenido información importante sobre la estructura de dichas membranas, especialmente se ha determinado una importante asimetría entre las caras de la membrana, asimetría que se atribuye al proceso de bombardeo que constituye la fase esencial del método de fabricación de las mismas.Palabras clave: Membranas, microfiltración, microscopía de fuerza atómica, porometría de aire, porosimetría de mercurio. Structural study of cyclopore microfiltration membranes.Atomic Force Microscopy (AFM), a recently developed technique, has proved to be a specially useful tool to characterise different types of material surfaces. In this work, we have used AFM to achieve a complete surface characterisation of several microfiltration membranes. These membranes are obtained by the track-etching method and, consequently, they are very suitable as test membranes, as having a very simple porous structure. For these membranes, several interesting structural parameters have been studied, as: porosity, pore size distributions and surface roughness of the membrane samples. All these parameters, conveniently analysed, have been compared with results obtained from other complementary characterisation techniques, to assure the realiability and validity of the obtained results. Important information on the membrane samples structure has been obtained. In that sense has been determined a clear asymmetry between both membrane sides, asymmetry that can be attributed to the manufacture process itself.Keywords: Membranes, microfiltration, atomic force microscopy, air displacement porometry, mercury porosimetry. INTRODUCCIÓNLas membranas de microfiltración presentan un extenso campo de utilización industrial, con aplicaciones plenamente desarrolladas en campos tan diversos como procesos farmacéuticos, biotecnología o producción de alimentos. A fin de optimizar la utilización de los diversos tipos de membranas existentes en el mercado en las diferentes aplicaciones industriales posibles, se hace necesario un completo y amplio conocimiento previo de las características y posibilidades de dichos filtros. En este sentido, su caracterización estructural, tanto superficial como en volumen, se puede acometer utilizando un amplio ...

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Section: Resultsunclassified

Section: Equipos Y Técnicas Experimentalesunclassified

Estudio estructural de membranas cyclopore de microfiltración

Calvo¹,

Palacio²,

Prádanos³

et al. 2000

Bol. Soc. Esp. Ceram. Vidr.

Self Cite

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“…The maximal pressure applied was 395 MPa, which corresponds to a minimum pore diameter D of 3.5 m. The pore-size distribution was extracted from the intrusion volume-pressure curve using the Pascal 140/440 Series software. [14][15][16][17][18][19] The total porosity T and solid density S of the preforms were obtained from Archimedes-principle based MB measurements with a Mettler AG204 Delta Range balance (Naenikon-Uster, Switzerland) adapted for buoyancy measurements. The main advantage of this method is that the open as well as the closed porosity is measured.…”

Section: B Preform Characterizationmentioning

confidence: 99%

“…The determination of the open porosity O by HP was performed with the Micrometrics AccuPyc 1330 instrument (GA). 16,17,20 From each powder batch A100T40-i and A100T200-i, three samples were prepared and measured. For samples free of moisture and of volatile substances, the skeletal density and open porosity may be determined with an error of ഛ0.01%.…”

Section: B Preform Characterizationmentioning

confidence: 99%

“…[14][15][16][17] Drawbacks of these methods are that models have to be assumed for the evaluation of the data, like cylindrical pores for MIP, and that the information is spatially not localized [18][19][20] ; moreover, some of the methods are destructive (MB, MIP). [21][22][23][24][25][26][27][28] BET and HP usually give results superior to MB and MIP and have the advantage of being nondestructive.…”

Section: Introductionmentioning

confidence: 99%

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X-ray computed micro tomography as complementary method for the characterization of activated porous ceramic preforms

et al. 2007

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X-ray computed micro tomography (CT) is an alternative technique to the classical methods such as mercury intrusion (MIP) and gas pycnometry (HP) to obtain the porosity, pore-size distribution, and density of porous materials. Besides the advantage of being a nondestructive method, it gives not only bulk properties, but also spatially resolved information. In the present work, uniaxially pressed porous alumina performs activated by titanium were analyzed with both the classical techniques and CT. The benefits and disadvantages of the applied measurement techniques were pointed out and discussed. With the generated data, development was proposed for an infiltration model under ideal conditions for the production of metal matrix composites (MMC) by pressureless melt infiltration of porous ceramic preforms. Therefore, the reliability of the results, received from different investigation techniques, was proved statistically and stereologically.

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