Porous Materials, Inc > Glossary of Terms

Glossary of Terms

glossaryThis is a small Glossary used here on our website. This is here to give you a better understanding of different terms used to describe our products and what they do.

Adsorption
a process that occurs when a gas or liquid solute accumulates on the surface of a solid or, more rarely, a liquid (adsorbent), forming a molecular or atomic film (the adsorbate). It is different from absorption, in which a substance diffuses into a liquid or solid to form a solution. The term sorption encompasses both processes, while desorption is the reverse process.
Area
a quantity expressing the two-dimensional size of a defined part of a surface, typically a region bounded by a closed curve. The term surface area refers to the total area of the exposed surface of a 3-dimensional solid, such as the sum of the areas of the exposed sides of a polyhedron.
Chemisorption
a type of adsorption whereby a molecule adheres to a surface through the formation of a chemical bond
Darcy
a unit of permeability, named after Henry Darcy. It is not an SI unit, but it is widely used in petroleum engineering and geology. Like other measures of permeability, a darcy has the same units as area.
Density
mass per unit volume
Diameter
the width of a circular or cylindrical object
Gurley (in relation to Porosity)
a unit describing the number of seconds required for 100 cubic centimeters (1 deciliter) of air to pass through 1.0 square inch of a given material at a given pressure differential.
Ideal Gas Law

The ideal gas law is the equation of state of a hypothetical ideal gas. It is a good approximation to the behavior of many gases under many conditions, although it has several limitations.

The state of an amount of gas is determined by its pressure, volume, and temperature. The modern form of the equation is:

pV = nRT

where p is the absolute pressure of the gas; V is the volume; n is the amount of substance; R is the gas constant; and T is the absolute temperature.

Liquid Extrusion
The forcing of liquid out of a sample
Liquid Intrusion
The forcing of liquid into a sample
Mean
Occupying a middle or intermediate position between two extremes
Nonwovens
Nonwoven textiles are those which are neither woven nor knit, for example felt.
Permeability
a measure of the ability of a material to transmit fluids; the rate of flow of a liquid or gas through a porous material
Pore
a minute opening or orifice, as in the skin or a leaf, for perspiration, absorption, etc.
Pore Size
the size of the opening in the sample
Pore Volume
the amount of space, measured in cubic units, that an object or substance occupies
Porosimetry
an analytical technique used to determine various quantifiable aspects of a material's porous nature, such as pore diameter, total pore volume, surface area, and bulk and absolute densities.
Porosity
a measure of the void spaces in a material, and is measured as a fraction, between 0-1, or as a percentage between 0-100%.
Rayl
one of two units of acoustic impedance. When sound waves pass through any physical substance the pressure of the waves causes the particles of the substance to move. The sound impedance is the ratio between the sound pressure and the particle velocity it produces. The impedance is one rayl if unit pressure produces unit velocity.
Surface Area
the summation of the areas of the exposed sides of an object
Viscosity
the property of a fluid that resists the force tending to cause the fluid to flow; a resistance to flow

See more definitions here.

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