What Is Unique About Mechanochemical Reactions?

Abstract

Mechanochemical reactions can provide compounds, phases, and microstructures that are essentially dierent from the products of ordinary reactions. In this paper, the origin of this uniqueness is discussed in light of the recent advances of the eld. It is claimed that the local availability of large batches of energy, well above kT , is the key feature of mechanochemical reactions. As a consequence, reactions that cannot occur thermally become possible, similarly to the reactions induced by the energy of photons in photochemistry. However, the situation is more complex, as macroscopic deformation aects many defect sites simultaneously. The direction of the mechanical load relative to the orientation of a molecule or the crystallographic axes of a solid can be important. Many mechanochemical reactions of organic compounds take place at low milling energy that is not sucient to break primary bonds, but the gentle mechanical grinding can inuence the relative position of macromolecules, leading to the formation of unique cocrystals and compounds. In inorganic systems, unusual products form due to forced mixing and the high defect density generated by intense milling.

Mechanochemical conversion of brominated POPs into useful oxybromides: a greener approach

“…Utilizing special high energy mills, it is possible to carry out MC transformations and reactions to produce a large variety of materials with improved peculiar properties that cannot be prepared by conventional methods232425. Moreover, MC procedures are green: Reactions are carried out at solid state, so solvent regeneration/disposal is not necessary, and processes in milling facilities are simpler than in conventional plants2627.…”

Preparation of polyvinyl alcohol/two‐dimensional transition metal dichalcogenides composites by high‐pressure homogenization

“…The PVA/WS 2 composite was prepared by freeze drying and even when the volume fraction of WS 2 was as high as 10%, the monolayer did not agglomerate. It was mainly applied in the food processing industry such as cosmetics and pharmaceuticals, [20][21][22][23][24] mainly by crushing the refined dispersion by HPH. 4 The high pressure homogenization (HPH) technology was discovered at the beginning of the last century.…”

“…4 The high pressure homogenization (HPH) technology was discovered at the beginning of the last century. It was mainly applied in the food processing industry such as cosmetics and pharmaceuticals, [20][21][22][23][24] mainly by crushing the refined dispersion by HPH. 25 The particles in the emulsion reached the micron or nanometer level, thereby improving some physical structure of the material.…”

Influence of mechanochemical treatment on thermal and structural properties of silica–collagen and hydroxyapatite–collagen composites

“…This approach opens the way to the development of modern technologies that are environmentally friendly. Therefore, the issues related to the use of alternative energy sources, including mechanical energy, are the subject of research by many authors (Balaz 2008;Boldyrev 2006;Boldyrev and Tkacova 2000;Sepelak and Becker 2012;Skubiszewska-Zięba 2011;Takacs 2014).…”