Conventional cigarettes have filter elements that can incorporate materials such as carbon. Certain commercially available filter cigarettes have particles or granules of carbon (e.g., an activated carbon material or an activated charcoal material) incorporated with the cellulose acetate tow or in cavities of a cellulose acetate material.
Activated carbon has strong physical adsorption forces, and high volumes of adsorbing porosity. Traditionally, activated carbon is formed by activation and carbonization of coconut husk, coal, wood, pitch, cellulose fibers, or polymer fibers, for example. Carbonization can be carried out at high temperatures, i.e., about 200° C. to about 800° C., in an inert atmosphere, followed by activation in an oxidization environment.
As a result of using single composition precursors, single modal pore distributions are attained in activated carbon because of the pore sizes of activated carbon being dependent upon the single composition precursors, and the carbonization and activation processes. Thus, the activated carbon has been provided with a single modal pore distribution, which in turn has only provided predictable, single function adsorption properties.
USPTO Backgrounds
USPTO Backgrounds