Mercury intrusion test

The principle of the water intrusion test derives from the mercury intrusion test, which (applicable to both hydrophilic and hydrophobic membranes) is restricted to laboratory conditions. The membrane is placed in contact with the fluid (water in the case of the water penetration test, mercury in the case of the mercury intrusion test), and the pressure is increased, with the purpose of forcing the fluid into the pores. The volume of fluid forced into the pores is a measure of pore size and void space volume and thus of filter integrity. 

Mercury intrusion test data show that before and after the consolidation the porosities of macropores (d > 10 pm) and the medium pores (5 pm < d < 10 pm) of the samples are very small the samples mainly contain the small pore (0.1 pm < d < 5 pm) the porosity of micropores (d < 0.1 pm) is greater than macropores and medium pores, but less than the small pores. Compared with the samples before consolidation, the small pores porosity has increased after consolidation and the quantity of macropores decreased. The reason is that soil particles slide or collapse due to the consolidation pressure. Therefore pores are compacted, and macropores reduce or even disappear. These conclusions are basically consistent with the SEM quantitative analysis. The samples mainly contain small pores before and after consolidation, pore size is primarily in the... 

The mercury porosimetry test (see Section 4.10) shown in Figure 6.30 was performed in a Micromeritics AutoPore IV-9500 automatic mercury porosimeter This study was carried out as follows the porosimeter sample holder chamber was evacuated up to 5 x 10 5 Torr, the equilibration time was 10 s and the mercury intrusion pressure range was from 0.0037 to 414 MPa, that is, the pores size range was from 335.7 to 0.003 pm. 

Each testing laboratory performed four measurements of each sample Bl, Gl, B2, G2, B3 and G3. The mercury intrusion measurements were carried out according to DIN 66133 [9]. Additionally, the bulk density was determined pycnometrically by mercury immediately after the low-pressure measurement. The experiments were performed according to routine procedures of the participating laboratories and instructions of the test coordinator. 

Experimental Procedure. Each sample was first characterized by both mercury intrusion and nitrogen sorption. Mercury intrusion measurements were replicated at least four times, and the solid residues from each analysis were collected and combined after the bulk of the mercury was decanted. These samples were washed free of mercury by using 50% nitric acid (25 mL per 0.5 g of solid) and then washed free of acid by filtering and reslurrying in demineralized water (six times with 50 mL per 0.5 g of solid). The washed samples were then rapidly cooled in liquid nitrogen and freeze-dried (Chemlab SB4). For comparison, samples of material that had not been analyzed with mercury intrusion were washed and dried in a similar manner to test for structural modification caused by the acid-washing technique. 

Mercury intrusion porosimetry (MIP) tests were performed to characterize the multiple-porosity network of the artificially prepared packing at different dry density values ranging from 1.2 to 1.95 Mg/m ... 

Other characterization tests were performed, such as porosimetry by mercury intrusion, thermal analysis and density by intrusion of helium, but the main characterization was possible from the tests already cited. As part of a more comprehensive characterization still in progress, other tests are being performed, namely durability performance tests such as penetration of chloride ions, electrical resistivity, capillary absorption and oxygen permeability. The results presented in this paper refer only related to the mechanical properties of compressive and tensile strength. 

On initial inspection the results obtained from serial sectioning of LMPA intruded samples appear at odds with the principle theory behind intrusion and retraction as predicted by the Washburn equation. But further inspection shows it is not the Washburn equation, but mercury porosimetry that is at fault. Pore network models have often been used to characterise the behaviour of pore structure in relation to mercury porosimetry. But the model is only as good as the assumptions and the data that it is based iqron. Without artificially shielding the network, the model caimot propa ly detomine the correct psd and cannot derive a more spatially accurate structure that could be used for diffusion and reaction modelling. In order to characterise the pore structure more accurately, we need to introduce some of the elements usually revealed by LMPA intrusion tests. 

Mercury intrusion data also may be misleading for porous materials having many inkbottle type pores, cp. middle portion of Fig. 1.1. In such situations high pressures are needed to overcome resistance of mercury to pass the narrow neck of the pore, i. e. the wider portion of the inkbottle pores will not be adequately reflected in the experimentally taken Vhj = Vng (p) curve. However, despite these disadvantages, mercury intrusion experiments often gives valuable information concerning the macro- and mesopores of a sorbent and hence very well may be used for comparative measurements and quality tests of sorbent samples. 

ASTM D4284-12. Standard test method for determining pore volume distribution of catalysts and catalyst carriers by mercury intrusion porosimetry... 

Additionally, porosity structure and strength development were determined for two Roman cements. For porosity structure measurements, prismatic specimens of 20 by 2 by 2 cm were cast in steel molds. The samples were demolded immediately after setting and cured under 100 % RH until tested. After the predetermined curing period, specimens for porosity stmctuie measurements were taken and immediately soaked in acetone for 24 h to stop the hydration of the cementitious materials. They were placed in a rotary vacuum flask at 20 °C for 4 h to remove acetone and to be dried. The porosity structure of the paste samples was determined using a Poremaster mercury intrusion porosimeter from Quantachrome, allowing the study of pore sizes in the range 440-0.0035 p,m. The measurements of strength are described in Ref. [4]. 

The CFP and Darcy air-permeability data discussed in Sect. 5.1 were correlated with mercury porosimetry (total PSD) and water porosimetry (hydrophobic PSD) before and after the consecutive aging/durability-testing experiments for cell M2. Mercury porosimetry can be effectively used to measure the total porosity and PSD of a GDL. This technique measures all porosity that exists (including constricted or dead-ended pores). The mercury intrusion volume also represents the hydrophobic plus hydrophilic surface domains because mercury is nonwetting for both types of pores. 

Ceramic membranes can be characterized in terms of pore size, pore size distribution, interfacial area, tortuosity, etc. Various tests are carried out to obtain information on the above such as bubble point, SEM, mercury porosimetry, etc. Currently industry uses mercury intrusion porosimetry to characterize pore size distribution. Since mercury cannot differentiate between open and blind pores (closed at one end), mercury porosimetry does not generate the size distribution of pores available for flow. In pennoporometry the pores are first filed with a liquid and then the liquid in the pores available for flow is expelled with a second fluid. Since liquid expulsion is unidirectional, this gives an accurate representation of e quality of the filter [63]. 

The test methods able to determine the complete geotextile PSD are mercury intrusion porosimetry (ASTM D4404), capillary flow (ASTM D6767), image analysis, and probabihstic approach (AydUek et al., 2005). 

ASTM D4404. Standard Test Method for Detamination of Pore Volume and Pore Volume Distribution of Soil and Rock by Mercury Intrusion Porosimetry. ASTM International, USA. 

Out of other physical methods used for porosity analysis, mercury intrusion porosimetry is worth mentioning. This method can be tried at all levels of electrode development, i.e. from catalyst to matrix stage. Testing of a matrix is done at low pressures (upto 400 kPa) so that the soft structure of the matrix is not deformed. Fig. 11 shows a typical result of PAFC cathode developed by the author s laboratory. The matrix is also characterized by other simple tests, like water loading, rate of water migration when dry matrix is dipped in one end etc. (Caires et al., 1997). 

Test Method for Determination of the Unit Cell Dimension of a Faujasite-Type Zeolite Test Method for Determination of Nitrogen Adsorption and Desorption Isotherms of Catalysts by Static Volumetric Measurements Test Method for Determining Pore Volume Distribution of Catalysts by Mercury Intrusion Porosimetry... 

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