Gas adsorption isotherm classification - Database & Sql Blog Articles

Classification of Gas Adsorption Isotherms If the absolute temperature, pressure, and action of the gas (adsorbate) and surface (adsorbent) are constant, the amount of adsorption on a particular surface is constant. Since the amount of gas adsorbed by a solid surface is a function of temperature, pressure, and affinity or energy, we can plot the amount of adsorption per unit weight of adsorbent at equilibrium temperature at a constant temperature. The curve of the amount of adsorption versus pressure at a constant temperature is the adsorption isotherm of a particular gas-solid interface. ?

At a constant temperature, only a certain amount of gas adsorption can exist on the solid surface corresponding to a certain adsorbate pressure. The adsorption isotherm can be obtained by measuring the corresponding adsorption amount under a series of relative pressures. The adsorption isotherm is the basic data for the adsorption phenomenon and the surface and pores of the solid. The surface and pore properties can be studied to calculate the specific surface area and pore size distribution.
There are six adsorption isotherms (Figure 1). The first five have been assigned a type number, and the sixth one has been added in recent years. The shape of the adsorption isotherm is directly related to the size and the number of holes.