Mechanochemistry

About: Mechanochemistry is a research topic. Over the lifetime, 1292 publications have been published within this topic receiving 33854 citations. The topic is also known as: mechanical chemistry.

Mechanochemistry: the mechanical activation of covalent bonds.

Abstract: Regarding the activation of chemical reactions, today’s chemist is used to thinking in terms of thermochemistry, electrochemistry, and photochemistry, which is reflected in the organization and content of the standard physical chemistry textbooks. The fourth way of chemical activation, mechanochemistry, is usually less well-known. The purpose of the present review is to give a survey of the classical works in mechanochemistry and put the key mechanochemical phenomena into perspective with recent results from atomic force microscopy and quantum molecular dynamics simulations. A detailed historical account on the development of mechanochemistry, with an emphasis on the mechanochemistry of solids, was recently given by Boldyrev and Tkáčová.1 The first written document of a mechanochemical reaction is found in a book by Theophrastus of Ephesus (371-286 B.C.), a student of Aristotle, “De Lapidibus” or “On stones”. If native cinnabar is rubbed in a brass mortar with a brass pestle in the presence of vinegar, metallic mercury is obtained. The mechanochemical reduction probably follows the reaction:1-3 * To whom correspondence should be addressed. Telephone: ++49-89-289-13417. Fax: ++49-89-289-13416. E-mail: martin.beyer@ch.tum.de (M.K.B.); Telephone: ++49-89-12651417. Fax: ++49-89-1265-1480. E-mail: clausen-schaumann@ fhm.edu (H.C.-S.). † Technische Universität München. ‡ Institut für Strahlenschutz. § Current address: Munich University of Applied Sciences. HgS + Cu f Hg + CuS (1) Volume 105, Number 8

Hallmarks of mechanochemistry: From nanoparticles to technology

Abstract: The aim of this review article on recent developments of mechanochemistry (nowadays established as a part of chemistry) is to provide a comprehensive overview of advances achieved in the field of atomistic processes, phase transformations, simple and multicomponent nanosystems and peculiarities of mechanochemical reactions. Industrial aspects with successful penetration into fields like materials engineering, heterogeneous catalysis and extractive metallurgy are also reviewed. The hallmarks of mechanochemistry include influencing reactivity of solids by the presence of solid-state defects, interphases and relaxation phenomena, enabling processes to take place under non-equilibrium conditions, creating a well-crystallized core of nanoparticles with disordered near-surface shell regions and performing simple dry time-convenient one-step syntheses. Underlying these hallmarks are technological consequences like preparing new nanomaterials with the desired properties or producing these materials in a reproducible way with high yield and under simple and easy operating conditions. The last but not least hallmark is enabling work under environmentally friendly and essentially waste-free conditions (822 references).

Mechanochemistry: A Force of Synthesis

Abstract: The past decade has seen a reawakening of solid-state approaches to chemical synthesis, driven by the search for new, cleaner synthetic methodologies. Mechanochemistry, i.e., chemical transformations initiated or sustained by mechanical force, has been advancing particularly rapidly, from a laboratory curiosity to a widely applicable technique that not only enables a cleaner route to chemical transformations but offers completely new opportunities in making and screening for molecules and materials. This Outlook provides a brief overview of the recent achievements and opportunities created by mechanochemistry, including access to materials, molecular targets, and synthetic strategies that are hard or even impossible to access by conventional means.

Mechanochemistry in Nanoscience and Minerals Engineering

Abstract: Mechanochemistry and Nanoscience.- High-Energy Milling.- Selected Identification Methods.- From Minerals to Nanoparticles.- Mechanochemistry in Minerals Engineering.- Applied Mechanochemistry.

The science and technology of mechanical alloying

Abstract: Mechanical alloying (MA) is a powder metallurgy processing technique involving cold welding, fracturing, and rewelding of powder particles in a high-energy ball mill, and has now become an established commercial technique to produce oxide dispersion strengthened (ODS) nickel- and iron-based materials. MA is also capable of synthesizing a variety of metastable phases, and in this respect, the capabilities of MA are similar to those of another important non-equilibrium processing technique, viz., rapid solidification processing (RSP). However, the “science” of MA is being investigated only during the past 10 years or so. The technique of mechanochemistry, on the other hand, has had a long history and the materials produced in this way have found a number of technological applications, e.g., in areas such as hydrogen storage materials, heaters, gas absorbers, fertilizers, catalysts, cosmetics, and waste management. The present paper discusses the basic mechanisms of formation of metastable phases (specifically supersaturated solid solutions and amorphous phases) by the technique of MA and these aspects are compared with those of RSP. Additionally, the variety of technological applications of mechanically alloyed products are highlighted.