Rus Articles Journal

Why to us mechanochemistry?

the Mechanochemistry studies chemical transformations of substances at mechanical influences (in mills, disintegrators, on rollers, extruders, etc.) at deformation, friction, shock compression. The transformations caused by friction allocate in the independent section called by tribokhimiy .

Plastic deformation of a solid body usually leads not only to change of a form of a solid body, but also to accumulation in it of the defects changing the physicist - chemical properties, including reactionary ability. Accumulation of defects is used in chemistry for acceleration of reactions with participation of solid substances, by decrease in temperature of processes and other ways of an intensification of chemical reactions in a firm phase. By a mechanochemical method make destruction of polymers, synthesis of intermetallid and ferrite, receive amorphous alloys, activate powder materials. Synthesis of the thermoelectric material FeSi2 in a planar spherical mill. And this refractory connections is received at the room temperature. It is used in ceramic cellular heaters.

Diamond synthesis in the way of direct phase transition from graphite was for the first time carried out by explosion in Sweden (1953), the USA (1954) and USSR (1959). Synthesis was made with use of energy of explosion, or directly from products of explosion of some explosives, with negative oxygen balance, trotyl is especially convenient for receiving diamonds. It is a cheap way of receiving diamonds. Explosive diamonds very small are also suitable only for abrasives and a dusting. The market of synthetic diamonds makes now, by estimates of various experts, 300-600 million carat (60-120 t ) in a year. For comparison: natural diamonds in a year about 150 million carats are around the world extracted (30 t ). You feel a mechanochemistry contribution to the industry of abrasives?

Sonokhimiya - the section of mechanochemistry, but in liquid. One of the reasons of chemical activation of liquids consists in cavitation emergence, for example, at absorption of ultrasound. Cavitation - education in the liquid environment of mass of the pulsing bubbles, leads to emergence of microshock pressure up to 800 MPas , to local increase of temperatures to 7400 K (by theoretical estimates), electric discharges, ionization. At a zakhlopyvaniye of cavitational cavities there is transmission of energy to the molecules of steam-gas mix directing in liquid and their dissociation.

Under the influence of ultrasound there is a sonolyuminestsention . The phenomenon it is that if to place the resonator in water and to create in it a standing spherical ultrasonic wave, then in water, in the center of the resonator, the bright, dot source of bluish light appears. The sound turns to the public! Estimates show that at a sonolyuminestsention there is a concentration of energy in one trillion times, that is on 12 orders!

From there is one of tempting opportunities of ultrasound in liquid - a cold thermonuclear reaction . The American physicists claim that they observed thermonuclear synthesis in experiments in desktop installation, however their work was apprehended by other researchers more than skeptically. Ruz Taleyarkhan from National Ok - Ridzhsky laboratory with some of coauthors insist that in their experiments on a sonolyuminestsention at a kollapsirovaniye of bubbles in deyterirovanny acetone there were temperatures in millions of degrees at which allegedly there was a thermonuclear synthesis. However two other his employees (Dan Shapira and Michael Soltmarsh) from Ok - the Ridge, after unfortunate attempt to repeat experiment, called its results in question. Authors of the publication, in turn, declared that their opponents just did not manage to calibrate devices properly. Other researchers of a sonolyuminestsention treat the message with a fair share of scepticism, but recognize that in case of confirmation it will become discovery of the first size.

The Institute of chemistry of a solid body and mechanochemistry of the Siberian Branch of the Russian Academy of Science (Novosibirsk), the European sonokhimichesky society works (European Society of Sonochemistry - ESS). It is possible to esteem: Haynike G. Tribokhimiya. M, 1987; Mechanochemical synthesis in inorganic chemistry / Under the editorship of E. G. Avvakumov - Novosibirsk: Science, FROM Academy of Sciences of the USSR, 1991; Chemistry and ultrasound. Under red. A.S. Kozmina. M.: World, 1993.