Geoscience Reference
In-Depth Information
Recently, M¨ ller and Bein
[180]
reported a unique mechanism of creation of
pores within pores—how to craft ordered hierarchical zeolites. This has prompted
several new avenues for the zeolites' synthesis and applications. A pioneering work
has been carried out by Bein
[181]
on the zeolitic host
guest interactions and
building blocks for the self-assembly of complex materials. Zeolite crystals are
used as building blocks for the self-assembly of thin films or 3D objects. A combi-
nation of weaker and stronger interactions ranging from dispersive forces, hydrogen
bonding, and electrostatic interactions to covalent bonding can be used to build
functional hierarchical constructs. This has led to the formation of several compo-
sites for various novel applications. Some of these aspects are discussed more elab-
orately in Chapter 10.
Researchers from United Kingdom are working on the application of zeolites in
health-related issues. Researchers are producing activated liquid zeolite or activated
clinoptilolite in water suspension (ACS), which is popularly being used to safely and
effectively increase the urinary excretion of potentially toxic heavy metals in healthy
volunteers without negatively impacting the electrolyte profiles, which controls the
nutritional levels of the participants
[182]
. ACS has also undergone 13 years of phar-
maceutical research in the United Sates with humans. Zeolite is included on the Food
and Drug Administration's generally recognized as safe (GRAS) list and thus is con-
sidered to be “completely safe.” Zeolite may well be one of the most potent natural
preventatives and treatments for cancer ever discovered.
Thus, the study of zeolites is a very popular field. A great diversity, both in
terms of compositions and applications, is being reported for zeolites. New struc-
tures have been discovered. All these suggest a great future for the zeolites, cover-
ing fields of selective and shape catalysis, oxidative catalysis, microelectronics,
optoelectronics, health and environmental issues, and so on.
References
[1] A.F. Cr¨nstedt, Om en obekant b¨rg art, som kallas Zeolites, Akad. Handl. Stockholm
17 (1756) 120.
[2] W.A. Deer, R.A. Howie, J. Zussman, Rock-Forming Minerals, vol. 4, Longmans,
New York, London, 1967, p. 351.
[3] E.S. Dana, A Text Book of Mineralogy, John Wiley & Sons, New York, NY, 1955.
p. 640.
[4] D. Loew, US Geography and Geological Exploration and Survey, West of 100th
Meridian, Part 6, vol. 3, 1875, p. 569.
[4a] Sir J. Murray and A.F. Renyard, Report on deep-sea deposits based on the specimens
collected during the voyage of H. M. S. Challenger in the years 1872 to 1876. John
Gibson, Pub., Printed for H. M. Stationery off., by Neill and company, 1891.
[5] D.S. Coombs, The nature and alteration of some Triassic sediments, Trans. R. Soc.
New Zealand 82 (1954) 65.
[6] H. Eichorn, Ueber die Einwirkung verd
¨
nnter Salzl
¨
sungen auf Silicate, Ann. Phys.
Chem. 105 (1858) 130.
