ABSTRACT
The driving force behind sorption is the formation of more stable systems that are characteristic with minimal thermodynamic free energies. Sorption is classified under adsorption and absorption. This classification is based on the location of captured molecules. Capturing gas molecules by solids is the result of attractive forces and electron correlations between the two types of interacting atoms/particles. Chemisorption energy is greater than physisorption energy. Both physical and chemical sorption may exist alongside each other. Adsorption processes are fundamentally based on the interactive forces between the particles or atoms of adsorbent and adsorbate, and they can be explained by the presence of force fields/potential fields formed around the particle counterparts. Due to the low adsorption binding energies, the physi-adsorbed molecules are fairly mobile over surfaces, and therefore they can serve as precursors for subsequent chemisorption. Uniform adsorption energy over an entire surface is considered at derivation of the Henry adsorption law.
