Captiv8
How does Captiv8 activated carbon cloth work?
The process, by which activated carbon cloth is able to adsorb contaminant molecules from the atmosphere, can be explained simply by considering the surface area contributed by cylindrical pores in the carbon fibre. The carbon molecules at the surface of the pore exert a weak force (Van der Waals force) directed towards the body of the carbon. Although this force is weak, the sheer number of pores ensure that any contaminant molecule that approaches the cloth is drawn into the pore and held fast by the force applied. Because the adsorption is by physical attraction, it is termed PHYSISORPTION.
This process is particularly effective towards large carbon containing molecules. It is less effective with respect to small fast moving molecules that contain no carbon. As can be imagined, although the attractive forces draw these molecules to the surface of the carbon, the molecule is too energetic to be stopped or adsorbed onto the carbon. In this case, the performance of the cloth can be improved by treating the surface of the carbon with some chemical that will react with the molecule to be removed. Thus for example an alkaline molecule such as ammonia can be removed by cloth treated with an acid such as citric acid. The pore structure of the cloth attracts the ammonia molecule to the surface and slows it down sufficiently for a chemical reaction to take place. This process is termed CHEMISORPTION, and Carbon Filter Technology Ltd has developed a wide range of systems to enhance performance in particular applications.
