Particle & Particle Systems Characterization

Cover image for Particle & Particle Systems Characterization

Special Issue: Analysis of Meso- and Macroporous Systems - Mercury Porosimetry, Capillary Pressure Analysis, Permporometry

June, 2006

Volume 23, Issue 1

Pages 3–111

    1. Contents: Part. Part. Syst. Charact. 1/2006 (pages 3–6)

      Article first published online: 26 JUN 2006 | DOI: 10.1002/ppsc.200690002

    2. Editorial: Part. Part. Syst. Charact. 1/2006 (pages 7–8)

      R. Denoyel and M. Thommes

      Article first published online: 26 JUN 2006 | DOI: 10.1002/ppsc.200690003

    3. Mercury Porosimetry: A General (Practical) Overview (pages 9–19)

      Herbert Giesche

      Article first published online: 26 JUN 2006 | DOI: 10.1002/ppsc.200601009

      The paper describes general concepts of mercury porosimetry measurements and provides an overview on the current status of pore-network analysis tools. Practical aspects of the technique are described as well as emphasizing the need for testing of model pore structures and the current status of pore network modeling software is given.

    4. Characterization of Mineral Building Materials by Mercury-Intrusion Porosimetry (pages 20–28)

      Katrin Rübner and Dirk Hoffmann

      Article first published online: 26 JUN 2006 | DOI: 10.1002/ppsc.200601008

      The application properties of mineral building materials are closely associated with porosity and pore size distribution. The entire pore size distribution curves are used to determine changes in pore structure and are correlated to engineering properties. These key values are applied as criteria to evaluate the quality and durability of a building material. The effects of preparation conditions and analysis techniques are discussed in detail.

    5. Capillary Pressure Curves of Sphere Packings: Correlation of Experimental Results and Comparison with Predictions from a Network Model of Pore Space (pages 29–39)

      John A. Dodds and Prashant Srivastava

      Article first published online: 26 JUN 2006 | DOI: 10.1002/ppsc.200501017

      A water suction apparatus is used to measure capillary pressure curves of glass beads (4 mono-sized and 4 ternary mixtures) in both loose and dense random packings. It is shown that the experimental results can be reduced to a single master curve which is further validated by experiments with a series of 5 grades of diatomaceous filter aid. The experiments are simulated with a 2D network model of pore space in packings giving capillary pressure curves comparable with the experimental results. The method therefore gives a relation between grain space and pore space through capillary pressure curves.

    6. Liquid Expulsion Permporometry – a Tool for Obtaining the Distribution of Flow-Through Pores (pages 40–47)

      Olga Šolcová, Vladimír Hejtmánek, Hana Šnajdaufová and Petr Schneider

      Article first published online: 26 JUN 2006 | DOI: 10.1002/ppsc.200601014

      The permporometry technique that is common in the field of membranes was extended to porous solids. The basic idea is the controlled expulsion of a liquid by increase of gas pressure difference. This allows determination of the pore size distribution (PSD). Two modes of measurement were suggested and tested including the contribution of the Knudsen flow mechanism. Both measurement modes were compared with results from mercury porosimetry and pseudo-steady state permeation. The specific advantages of each method are discussed.

    7. Domain Complexion Diagrams Related to Mercury Intrusion-Extrusion in Monte Carlo-Simulated Porous Networks (pages 48–60)

      Carlos Felipe, Salomón Cordero, Isaac Kornhauser, Giorgio Zgrablich, Raul López and Fernando Rojas

      Article first published online: 26 JUN 2006 | DOI: 10.1002/ppsc.200601013

      Hg intrusion-extrusion processes in porous networks are simulated by a Monte Carlo procedure considering canthotaxis at site-bond joints and snap-off of Hg threads. Hg porosimetry is illustrated in terms of domain complexion diagrams depicting the sites and bonds of given sizes that are Hg-filled or not. Using this representation the effects during intrusion-extrusion caused by voids and throats in the porous medium are elucidated in detail and the effects of porosity structure on the obtained hysteresis curves are discussed.

    8. The Physical Significance of Mercury Porosity Hysteresis in the Characterization of Calcined Precipitated Alumina (pages 61–71)

      J. Donald Carruthers

      Article first published online: 26 JUN 2006 | DOI: 10.1002/ppsc.200601016

      The target specifications of activated alumina (e.g. surface area, total pore volume, pore size distribution and density) for application as a catalyst support or as an adsorbent depend on the ultimate application. In this work mercury porosimetry measurements on a wide variety of calcined aluminas is contrasted with thermogravimetric analyses (TGA) of the source aluminum oxide hydrates. The results imply a ‘connectivity’, or internal structure, explanation for porosimetry hysteresis in calcined aluminas.

    9. Non Intrusive Mercury Porosimetry: Pyrolysis of Resorcinol-Formaldehyde Xerogels (pages 72–81)

      Nathalie Job, René Pirard, Jean-Paul Pirard and Christelle Alié

      Article first published online: 26 JUN 2006 | DOI: 10.1002/ppsc.200601011

      Some materials examined by mercury porosimetry are densified by the isostatic pressure. Expecially, very porous materials formed by aggregated particles undergoe a hierarchical pore collapse. Thus, an accurate data analysis requires the previous determination of the mechanism of pore collapse in order to account for. This work examines the complex and unusual behavior of gels when submitted to mercury porosimetry. The unusual behavior encountered complicates the mechanism identification and, therefore, the equation selection. However, the major part of the volume distribution as a function of the pore size can be determined with a good accuracy.

    10. Using Nano-Cast Model Porous Media and Integrated Gas Sorption to Improve Fundamental Understanding and Data Interpretation in Mercury Porosimetry (pages 82–93)

      Sean P. Rigby, Irene O. Evbuomwan, Matthew J. Watt-Smith, Karen Edler and Robin S. Fletcher

      Article first published online: 26 JUN 2006 | DOI: 10.1002/ppsc.200601012

      The mechanisms of entrapment, and the nanoscopic spatial distribution, of the residual mercury within nano-cast and amorphous porous media (pore sizes ∼1–100 nm) following high-pressure penetration have been studied. It is shown that, even at the nano-scale, one of the same two principle mechanisms can be observed as in macroscopic porous materials. The mechanisms and geometrical conditions for entrapment are elucidated. This enables information not previously available for nanoporous systems which can be incorporated into simulations of mercury porosimetry on those materials.

    11. Application of Mercury Porosimetry to Predict the Porosity and Strength of Ceramic Catalyst Supports (pages 94–100)

      Malcolm Yates

      Article first published online: 26 JUN 2006 | DOI: 10.1002/ppsc.200601015

      Ceramic based monolithic supports are used in many catalytic reactions. Maximum porosity is desired in order to ensure a high diffusional transport. However, an upper limit for porosity is given by the required mechanical strength. Here we show how the mechanical strength and porosity of ceramic catalyst supports are related to the primary particle size of the raw materials, initial composition and final heat treatment temperature.

    12. Application of Mercury Intrusion Porosimetry for Characterization of Combined Micro- and Mesoporous Zeolites (pages 101–106)

      Johan C. Groen, Sander Brouwer, Louk A. A. Peffer and Javier Pérez-Ramírez

      Article first published online: 26 JUN 2006 | DOI: 10.1002/ppsc.200601010

      Combined micro- and mesoporous ZSM-5 zeolites have been investigated using mercury porosimetry (MP) and N2 gas adsorption. These methods complement to each other and a fairly good correlation has been obtained for the mesopore size and volume as derived from both techniques. Effects of compression and reproducibility issues of both methods are discussed in detail. Besides, MP provides supplementary information on the presence of macropores.