Adsorption Process J。=f(W,T,,P) Adsorbate P=pressure of the adsorbate I=interaction between adsorbate and adsorbent If w, T, and I are made constant, the above equation can be written as J ere Adsorbent pressure of adsorbate S. Lowell J. E. Shields, Powder Surface Area and P saturated pressure of adsorptive Porosity, 3rd Ed. Chapman&Hall,New York, 1991 Gas Sorption: Isotherm 。 Desorption isotherm P pressure of adsorbate p saturated pressure of adsorptive Adsorption isotherm >Isotherm is a measure of the volume of gas adsorbed at a constant temperature function pressure >Isotherms can be grouped into SIX lasse10 http://nano.materials.drexel.edu Adsorption Process Adsorption Process Adsorbent Adsorbate saturated pressure of adsorptive pressure of adsorbate where equation can be written as: If W, T, and I are made constant, the above interaction between adsorbate and adsorbent. temperature; pressure of the adsorbate; weight of adsorbent; volume of gas adsorbed; where ( , , , ) = ⎟ ⎟ ⎠ ⎞ ⎜ ⎜ ⎝ ⎛ = = = = = = = p p p p f I T P W f W T I P o V o V V a a a Equation of adsorption isotherm S. Lowell & J. E. Shields, Powder Surface Area and Porosity, 3rd Ed. Chapman & Hall, New York, 1991 http://nano.materials.drexel.edu Gas Sorption: Isotherm Adsorption isotherm ¾Isotherm is a measure of the volume of gas adsorbed at a constant temperature as a function of gas pressure. ¾Isotherms can be grouped into six classes. saturated pressure of adsorptive pressure of adsorbate where = ⎟ ⎟ ⎠ ⎞ ⎜ ⎜ ⎝ ⎛ = p p p p f o V o a Va Desorption isotherm p po