Definition - What does Chemisorption mean?
Chemisorption is a chemical adsorption process, caused by a reaction on an exposed surface, which creates an electronic bond between the surface and the adsorbate. During the chemical reaction, a distinct chemical species is created on the adsorbent surface, which causes the bond to be created.
Chemisorption is used in development, monitoring and measuring of corrosion inhibitors and is used for measuring surface active sites on a substrate.
Corrosionpedia explains Chemisorption
Chemisorption generally involves either a charge sharing or charge transfer between a solid metal substrate and an adsorbent, such as the corrosion inhibitor molecule. Chemically adsorbed inhibitors on the metal surface interfere with metal dissolution in an electrolyte fluid.
The effectiveness of chemisorbed organic molecules depends upon:
- Molecular size and ability to donate electrons to the substrate
- Physical adsorption (physisorption), which retains the chemical species within the the adsorbate and the substrate surface in its original condition
The chemisorption process involves the creation of strong electronic bonds between adsorbate molecules and certain surface locations, which are known as surface active sites.
Chemisorption is irreversible and involves more heat than physical adsorption.