Effect of plasma treatment on structure and surface properties of montmorillonite

• Montmorillonite powder was plasma treated.
• Ar plasma in fluidized bed reactor was used.
• Dehydration after plasma treatment was observed.
• The plasma treatment has similar effect to thermal treatment.
• The process is reversible.

Plasma treatment of montmorillonite has been investigated as a prerequisite for design of functional nanostructures, based on clay minerals. The effect of short-term (20 s) plasma treatment on structure and bonding of montmorillonite has been analyzed using combination of X-ray powder diffraction and infrared spectroscopy. Results showed that dehydration starts at low discharge power 10 W and at 50 W is completed. The effect of the plasma treatment was compared to the effect of the heat treatment (8 h at 450 °C). Both treatments can be considered as similar when dehydration takes place. However, the dehydroxylation does not seem to be triggered by the plasma treatment. Therefore for dehydration only, the plasma treatment can be used instead of much more energy consuming thermal treatment.