Gas Adsorption Studies on Electrically Charged Carbon Surfaces
(Funded by the Chemical Industry Fund)
The enrichment of particles from a fluid phase on the surface of a solid is called adsorption. It can be distinguished between physical adsorption (“physisorption”) and chemical adsorption (“chemisorption”) that are based on purely physical van der Waals interaction and the formation of chemical bonds, respectively. Physisorption of gases on solid surfaces is widely applied for gas storage and removal of toxic compounds by filtration (e.g., in gas masks). Activated carbon materials with high surface area are crucial components in such applications due to their high uptakes and chemical stability. The adsorption capacity and selectivity towards the compound to be adsorbed can be influenced by the structural properties of the carbon adsorbent such as the pore size and surface chemistry. Pressure and temperature are external stimuli that can be changed to control the adsorption process. Within this project, we investigate the influence of electric charge on the carbon materials in combination with the structural properties on the gas adsorption behavior. It is the aim to increase the uptake and selectivity in gas purification processes, but also to get new insights into the thermodynamic fundamentals of physisorption processes.