Search results
Results from the WOW.Com Content Network
Porosimetry is an analytical technique used to determine various quantifiable aspects of a material's porous structure, such as pore diameter, total pore volume, surface area, and bulk and absolute densities. The technique involves the intrusion of a non-wetting liquid (often mercury) at high pressure into a material through the use of a ...
In capillary flow porometry, in opposition to mercury intrusion porosimetry, the wetting liquid enters spontaneously the pores of the sample ensuring a total wetting of the material, and therefore the contact angle of the wetting liquid with the sample is 0 and the previous formula can be simplified as: P= 4*γ/D.
Powder wettability measurement with the Washburn method. In its most general form the Lucas Washburn equation describes the penetration length of a liquid into a capillary pore or tube with time as = (), where is a simplified diffusion coefficient. [4]
However, simple cooling of an all-liquid sample usually leads to a state of non-equilibrium super cooling and only eventual non-equilibrium freezing – to obtain a measurement of the equilibrium freezing event, it is necessary to first cool enough to freeze a sample with excess liquid outside the pores, then warm the sample until the liquid in ...
%PDF-1.3 %Äåòåë§ó ÐÄÆ 2 0 obj /Length 4 0 R /Filter /FlateDecode >> stream xÚí}[Ó ·‘å;~E?z#¤žÂ ðì‹ìðx6ÂŽõÄ(bž) ...
The samples' total volume and pore space volume were measured in order to calculate the porosities. Measuring pore space volume. A helium pyrometer was used to calculate the volume of the pores and relied on Boyle's law. (P 1 V 1 =P 2 V 2) and helium gas, which easily passes through tiny holes and is inert, to identify the solid fraction of a ...
A sample of known bulk volume is enclosed in a container of known volume. It is connected to another container with a known volume which is evacuated (i.e., near vacuum pressure). When a valve connecting the two containers is opened, gas passes from the first container to the second until a uniform pressure distribution is attained.
BET model of multilayer adsorption, that is, a random distribution of sites covered by one, two, three, etc., adsorbate molecules. The concept of the theory is an extension of the Langmuir theory, which is a theory for monolayer molecular adsorption, to multilayer adsorption with the following hypotheses: