electronic systems. Polanyi wrote to London asking, “Are these forces subject to screening by intervening molecules? Would a solid acting by these forces possess a spatially fixed adsorption potential?” After computational analysis, a joint publication was made between Polanyi and London claiming that the adsorptive forces behaved similarly to the model that Polanyi had proposed. Further research Polanyi's theory has historical significance whose work has been used a foundation for other models, such as the theory of volume filling micropores (TVFM) and the Dubinin–Radushkevich theory. Other research have been performed loosely involving the potential theory of Polanyi such as the capillary condensation phenomenon discovered by Zsigmondy. Unlike Poylani's theory which involves a flat surface, Zsigmondy's research involves a porous structure like silica materials. His research proved that condensation of vapors can occur in narrow pores below the standard saturated vapour pressure. Theory Polanyi potential adsorption theory The Polanyi potential adsorption theory is based on the assumption that the molecules near a surface move according to a potential, similar to that of gravity or electric fields. This model is applicable in the case of gases at a surface at constant temperature. Gas molecules move closer to that surface when the pressure is higher than the equilibrium vapor pressure. The change in potential relative to the distance from the surface can be calculated using the formula for difference of the chemical potential, where is the chemical potential, is the molar entropy, is the molar volume, and is the molar internal energy. At equilibrium, the chemical potential of a gas at a distance from a surface, , is equal to the chemical potential of the gas at an infinitely large distance from the surface, . As a result, the integration from an infinitely far distance to r distance from the surface leads to where is the partial pressure at distance r and is the partial pressure at infinite distance from the surface. Since the temperature remains constant, the difference in chemical potential formula can be integrated over pressures and By setting the , the equation can be simplified to Using the ideal gas law, , the following formula is obtained Since gas condenses into a liquid on a surface when the pressure of the gas exceeds the equilibrium vapor pressure, , we can assume a liquid film forms over the surface of thickness, . The energy at is Considering that the partial pressure