Mercury intrusion apparatus

In this study mercury intrusion porosimetry (MIP) analyses were employed to determine the pore size distribution and pore volume over the range of approximately 100 pm down to 7.5 nm diameter, utilising CE Instruments Pascal 140/240 apparatus, on samples previously dried overnight at 150°C. The pressure/volume data were analysed by use of the Washburn Equation [14] assuming a cylindrical nonintersecting pore model and taking the mercury contact angle as 141° and surface tension as 484 mN m [10]. For the monolith... 

Transmission microscopy is realized using a Philips CM30 apparatus at 300 KV. DRX spectra were realized on a diffractometer Philips 1700 by scanning between 5 to 70° at l°/mn. Porous distribution is determined by mercury intrusion after elimination of gas over night at 200°C in an oven (Autopore II 9220 V3.01). Acidobasic properties characteristics of solids were estimated by studying the reactivity of 2-methyl 3-butyn-2-ol (MBOH) (ref. 3). 

Crush strengths were measured using a Chatillon apparatus. Values reported were the average of 20 determinations. Pore size distributions were measured by mercury intrusion using a Micromeritics Autopore 9220. A contact angle of 130° was assumed for all measurements. 

In summary, both pore size and pore size distribution can be determined by the mercury intrusion technique. One disadvantage is that the apparatus is rather expensive and not widely used as a consequence. Another point is that small pore sizes require high pressures and damage of the membrane structure may occur. Furthermore, the method measures all the pores present in the structure, including dead-end pores. 

The apparatus used was an Autopore III from Micromeritics. The powder was outgassed at room temperature until the residual pressure was equal to 20 pm Hg When the pressure is increased, mercury penetrates into the powder and the corresponding intrusion volume is... 

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