Mercury porosimetry

1981 ◽  
pp. 564-582
Author(s):  
Terence Allen
Keyword(s):  
Mercury Porosimetry

Porous Structure and Transport Properties of a Carbonized Phenolic Resin

1995 ◽  
Vol 60 (2) ◽  
pp. 172-187 ◽  
Author(s):  
Pavel Fott ◽  
František Kolář ◽  
Zuzana Weishauptová
Keyword(s):  
Porous Structure ◽  
Transport Properties ◽  
Phenolic Resin ◽  
Arrhenius Equation ◽  
Mercury Porosimetry ◽  
Micropore Volume ◽  
Microporous Structure ◽  
Wetting And Drying ◽  
Phenolic Resins ◽  
Kinetics Of

On carbonizing phenolic resins, the development of porous structure takes place which influences the transport properties of carbonized materials. To give a true picture of this effect, specimens in the shape of plates were prepared and carbonized at various temperatures. The carbonizates obtained were studied by adsorption methods, electron microscopy, and mercury porosimetry. Diffusivities were evaluated in terms of measuring the kinetics of wetting and drying. It was found out that the porous structure of specimens in different stages of carbonization is formed mostly by micropores whose volumes were within 0.06 to 0.22 cm3/g. The maximum micropore volume is reached at the temperature of 750 °C. The dependence of diffusivity on the carbonization temperature is nearly constant at first, begins to increase in the vicinity of 400 °C, and at 600 °C attains its maximum. The experimental results reached are in agreement with the conception of the development and gradual closing of the microporous structure in the course of carbonization. The dependence of diffusivity on temperature can be expressed by the Arrhenius equation. In this connection, two possible models of mass transport were discussed.

Removal of Heavy Metal Ions from Aqueous Solution by Manganese Dioxide-Coated Polypropylene Granules: An Implication of Rainwater Runoff Treatment

2007 ◽  
Vol 544-545 ◽  
pp. 131-134
Author(s):  
Sardor Abdukakharovich Mavlyankariev ◽  
Dong Seok Rhee
Keyword(s):  
Metal Ions ◽  
Manganese Dioxide ◽  
Surface Area ◽  
Mercury Porosimetry ◽  
Surface Characteristics ◽  
Metal Species ◽  
Adsorption Model ◽  
Rainwater Runoff ◽  
Flow Through ◽  
Fast Removal

Modified polypropylene granules (MDPG) were coated by manganese dioxide and their surface and adsorptive characteristics were studied. Surface characteristics of the adsorbent were investigated by B.E.T. surface area and mercury porosimetry. Coating has significantly increased the surface area of granules from 0.12 m 2 /g B.E.T. N 2 to 15.42 m 2 /g. Gas pycnometry measurements resulted in low density of 0.13 g/cm 3 for uncoated granules, the fact ascribed to 0.65 porosity measured. Coating increased micro pore volume of raw granules by a factor of 58. Adsorption experiments were conducted in column flow-through reactors at pH 6.0 and 10 g/L sorbent dosage for mixture of four metal species, each having 5 mg/L initial concentration. More than 60 % of Pb and Cu was removed within first 20 min, whereas just over 29 and 13 % for Cd and Zn respectively. Furthermore, more than 99, 84, 40, 16 % of Pb, Cu, Cd, and Zn was removed within 1 h. Adsorption efficiencies for 5 ppm of initial metal concentration at pH 5.0 and 10 g/L sorbent/solute ratio resulted in 4.9, 3.9 mg of Pb and Cu sorbed per gram of sorbent. And these ratios for separate metal ions were substantially higher than those for the mixture of the four metal ions. For 5 g/L of sorbent under the same parameters, removal efficiencies of Cd and Zn were respectively 0.98, 0.75 mg/g, correlating well with Freundlich adsorption model. Adsorption kinetics showed relatively fast removal rates within first 5 h of sorption. Desorption resulted in eluting 57, 70, 76, 78 % of the initial feeding concentrations for Pb, Cu, Cd, Zn, respectively.

Induced polarization and pore radius — A discussion

Geophysics ◽  
2016 ◽  
Vol 81 (5) ◽  
pp. D519-D526 ◽  
Author(s):  
Andreas Weller ◽  
Zeyu Zhang ◽  
Lee Slater ◽  
Sabine Kruschwitz ◽  
Matthias Halisch
Keyword(s):  
Diffusion Coefficient ◽  
Relaxation Time ◽  
Diffusion Coefficients ◽  
Pore Radius ◽  
Mercury Porosimetry ◽  
Induced Polarization ◽  
Reliable Estimate ◽  
Characteristic Relaxation Time ◽  
A Value ◽  
Apparent Diffusion

Permeability estimation from induced polarization (IP) measurements is based on a fundamental premise that the characteristic relaxation time [Formula: see text] is related to the effective hydraulic radius [Formula: see text] controlling fluid flow. The approach requires a reliable estimate of the diffusion coefficient of the ions in the electrical double layer. Others have assumed a value for the diffusion coefficient, or postulated different values for clay versus clay-free rocks. We have examined the link between a widely used single estimate of [Formula: see text] and [Formula: see text] for an extensive database of sandstone samples, in which mercury porosimetry data confirm that [Formula: see text] is reliably determined from a modification of the Hagen-Poiseuille equation assuming that the electrical tortuosity is equal to the hydraulic tortuosity. Our database does not support the existence of one or two distinct representative diffusion coefficients but instead demonstrates strong evidence for six orders of magnitude of variation in an apparent diffusion coefficient that is well-correlated with [Formula: see text] and the specific surface area per unit pore volume [Formula: see text]. Two scenarios can explain our findings: (1) the length scale defined by [Formula: see text] is not equal to [Formula: see text] and is likely much longer due to the control of pore-surface roughness or (2) the range of diffusion coefficients is large and likely determined by the relative proportions of the different minerals (e.g., silica and clays) making up the rock. In either case, the estimation of [Formula: see text] (and hence permeability) is inherently uncertain from a single characteristic IP relaxation time as considered in this study.

Basic Physical and Mechanical Properties of Composites Based on Three Different Cements

2016 ◽  
Vol 677 ◽  
pp. 186-190 ◽  
Author(s):  
Monika Čáchová ◽  
Eva Vejmelková ◽  
Kateřina Šestáková ◽  
Pavel Reiterman ◽  
Martin Keppert ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Portland Cement ◽  
Open Porosity ◽  
Mercury Porosimetry ◽  
Physical And Mechanical Properties ◽  
Mineralogical Composition ◽  
Physical Parameters ◽  
Vacuum Saturation ◽  
Saturation Method ◽  
Properties Of Composites

This article is focused on cement based composites. Two cements differing in mineralogical composition are utilised as main binder in composites mixtures. Results of measured physical parameters of studied materials are presented. For the sake of comparison, a reference material with Portland cement was also prepared. Basic physical properties (measured by water vacuum saturation method and by helium pycnometry), characterizations of pore system (determined by mercury porosimetry) and mechanical properties are the matter of this study. Composites show various open porosity; the results of open porosity of materials containing special cements show higher values, in comparison with composite based on Portland cement. This fact of course influences other material characteristics - mainly mechanical properties.

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