In addition to electrostatic interaction (physisorption) of PSC molecules on the iron surface, molecular adsorption may also play a role in the adsorption process.
In addition to electrostatic interaction (physisorption) of BPP molecules on the copper surface, molecular adsorption may also play a role in the adsorption process.
Generally, the values of ΔG ads up to −20 kJ/mol is an indication of electrostatic interaction (physisorption) of charged molecules and the metal, while those around −40 kJ mol−1 stands for chemisorption.
The free energy change of adsorption, enthalpy of adsorption and entropy of adsorption indicated that the adsorption process is spontaneous and exothermic and the phytochemical constituents of Tilia cordata extract adsorbed at the metal-surface interface and produce a protective barrier by the process of electrostatic adsorption (physisorption).
The process of coupling biocomelecules to UCNPs can be provided primarily by two methods: (i) First is electrostatic or physisorption; it provides a straightforward noncovalent force to couple with the biomolecules.
Generally, the values of ∆Gads up to − 20 kJ/mol signify physisorption, which is consistent with electrostatic interaction between charged molecules and a charged metal.
Application of charged polymer chains as additives for lubricating neutral surfaces in aqueous environment, especially via polymer physisorption, is generally impeded by the electrostatic repulsion between adjacent polymers on the surface.
Generally, the change in free energy values of −20 kJ mol−1 or less negative are associated with an electrostatic interaction between charged molecules and charged metal surface (physisorption); those above −40 kJ mol−1 or more negative involve charge sharing or transfer from the inhibitor molecules to the metal surface to form a coordinate covalent bond (chemisorption) [27, 28].
Generally, values of ∆ Gads around −20 kJ mol−1 or lower are consistent with the electrostatic interaction between charged molecules and the charged metal surface (physisorption); those around −40 kJ mol−1 or higher involve charge sharing or transfer from organic molecules to the metal surface to form a coordinate type of metal bond (chemisorption) [30].
In general, the values of ΔG ads o up to −20 kJ mol−1 are compatible with the electrostatic interaction between the charged inhibitor molecules and the charged metal surface (physisorption), and those which are more negative than −40 kJ mol−1 involve charge sharing or charge transfer from the inhibitor molecules to the metal surface (chemisorption) [36].
