Mechanochemistry

The research is performed mainly by Dr. Svetlana Lugovskoy, with some minor assistance of mine.

Mechanochemistry is a method of inducing chemical changes in a substance by mechanical actions. A simplest example of mechanochemical reaction can be seen in lighting cook matches: you strike it (a purely mechanical action) and it is lit (chemical reaction).

In our laboratory mechanochemical processes are realized in high-energy planetary ball mills (PM100, Retsch).

A milling jar made of hard alloys or ceramics is "charged" by solid or colloidal reactants and several grinding balls of different diameters. The jar is air-tight sealed and fixed in a support. The jar is then rotated around two axes (this is why the mill is called "planetary") and the balls inside it develop very high accelerations (to 600G for some models). Moving balls hit the walls of the jar where the reacting mixture is spread by the action of the centrifugal force thus providing severe mechanical impact on the reactants.

The effect of mechanochemical milling can be very diverse. We have successfully used it for the following tasks:

  • Polymerization reactions: in 2-5 minutes you obtain what you would have obtained after a couple of hours of a conventional "wet" process;
  • Alloying: metals are alloyed without high-temperature melting;
  • Grinding: inert materials are ground to nanometric sizes;
  • Surface modification: micron size particles demonstrate optical properties different than without the mechanochemical treatment.