ABSTRACT
Activated charcoal contains an internal network of very ne pores that adds up to an extensive surface area. One gram of this material typically exposes a few thousands of square meters of surface area. The surface has a high afnity to adsorb all kinds of substances. For this reason, activated charcoal has a long-standing reputation to be used in air and water lters, in gas masks, and, most eminently, as a universal antidote to drugs, chemicals, and toxins. Charcoal is inert to the body. In other words, it slides through the stomach and the intestines without being absorbed or metabolized. On its way, it binds (toxic) substances, carrying them throughout the digestive system so that they can be eliminated from the body. By doing so, activated charcoal has saved the lives of people that have consumed lethal doses of poisons such as microbial toxins in contaminated food, household chemicals, sedatives, party drugs, and pain killers. (Figure courtesy of Norit N.V., Amersfoort, the Netherlands.)
Adsorption is the spontaneous accumulation of matter at an interface. We came across this phenomenon in different contexts in foregoing chapters, for instance, in Section 3.11 where the Gibbs adsorption equation is derived and in Section 7.3 where adsorbed monolayers (Gibbs monolayers) at liquid interfaces are distinguished from spread monolayers (Langmuir’s monolayers).
