24 May 2012
As explained by Antonio Torrisi, MSc Science Communication
Zeolites, literally “boiling stones” from the Greek words zeo (to boil) and lithos (stone), owe their name to the Swedish mineralogist Axel Friedrik Cronstedt, who observed water vapours being released from these materials when heated. Zeolites are made of silica-like sand and aluminium. They have a porous structure similar to a sponge, with cavities as small as thousandths of microns. The cavities form regular channels through which gas and water can move. Zeolites can be either natural or synthetic materials and are economically important. Their industrial uses include as adsorbents for water purification and gas separation in industrial processes, or as catalysts for the ‘cracking’ of petrol to make gasoline. Nanoparticles of zeolites could also be introduced into the human body to deliver anti-cancer drug molecules contained in the zeolite’s cavities, as a therapy that would attack only the sick cells, sparing the healthy ones. Advanced applications of zeolites aim to capture radioactive elements, which are large, positively charged, spherical atoms. They can be trapped in the cavities of the zeolites and can, therefore, be removed from soil or water.