Halloysite is an aluminosilicate clay mineral with the empirical formula Al2Si2O5(OH)4. Its main constituents are aluminium (20.90%), silicon (21.76%) and hydrogen (1.56%). Halloysite typically forms by hydrothermal alteration of alumino-silicate minerals.[4] It can occur intermixed with dickite, kaolinite, montmorillonite and other clay minerals. X-ray diffraction studies are required for positive identification. It was first described in 1826 and named after the Belgian geologist Omalius d'Halloy.
Halloysite is an efficient adsorbent both for cations and anions. It has also been used as a petroleum cracking catalyst, and Exxon has developed a cracking catalyst based on synthetic halloysite in the 1970s. Owing to its structure, halloysite can be used as filler in either natural or modified forms in nanocomposites.
Halloysite nanotube can be intercalated with catalytic metal nanoparticles made of silver, ruthenium, rhodium, platinum or cobalt, thereby serving as a catalyst support.[5]Besides supporting nanoparticles, halloysite nanotubes can also be used as a template to produce round well-dispersed nanoparticles (NPs). For example, bismuth and bismuth subcarbonate NPs with controlled size (~7 nm) were synthesized in water. Importantly, when halloysite was not used, large nanoplates instead of round spheres are obtained.
AXE Price at posting:
15.0¢ Sentiment: Buy Disclosure: Not Held
A personalised tool to help users track selected stocks. Delivering real-time notifications on price updates, announcements, and performance stats on each to help make informed investment decisions.
(20min delay)