Super multi-use minerals unveiled

From PhysOrg.com - latest science and technology news:

This material forms around a third of the average packet of washing powder and helps refine 99 per cent of the world's petrol. It is also used to clean up nuclear waste. This extremely useful material is a zeolite. In its natural form it originates from volcanoes but it is synthesised for commercial purposes. A European team of scientists has revealed, for the first time, its chemical structure using the ESRF. This research, published in Nature Materials on 22 June, opens doors to more effective zeolites in the future. Zeolites are crystalline white minerals, mostly made of aluminium, silicon and oxygen. Their structure is like molecular scaffolding, similar to a sieve. Thanks to this structure, they are frequently used as a "molecular sieve". This means that with their pores they can separate different molecules and cause different reactions, which are crucial in treating petrol and producing chemicals. Zeolites can also provoke ion exchange, which is useful in water softening or in the removal of nuclear waste (by filtering the radioactive components). Due to their importance in industry, there is extensive research on zeolites world-wide. However, a crucial aspect about these minerals is still not known. Their functioning and effectiveness depends on different parameters, such as the size of their pores and the distribution of aluminium in the structure of the zeolites. However, the location of the active aluminium remains unknown in many of these materials. The team from the ETH Zurich, the European Synchrotron Radiation Facility (ESRF), Diamond Light source, the University of Torino and the University of Hamburg have determined unambiguously and directly the distribution of aluminium in zeolites using the technique of X-rays standing wave at the ESRF. The object of the study was a scolecite zeolite, a natural mineral stemming from the zeolite-rich region of Puna in India. Natural zeolites are not so commonly used in industry because they tend to have more impurities than those synthesised, but they can be used in cleaning nuclear waste. After the Chernobyl catastrophe, tons of zeolites were used with the aim of cleaning the radioactively contaminated area.

Read the whole article