The aim of this critical review is to provide a broad but digestible overview of mechanochemical synthesis, i.e. reactions conducted by grinding solid reactants together with no or minimal solvent. Although mechanochemistry has historically been a sideline approach to synthesis it may soon move into the mainstream because it is increasingly apparent that it can be practical, and even advantageous, and because of the opportunities it provides for developing more sustainable methods. Concentrating on recent advances, this article covers industrial aspects, inorganic materials, organic synthesis, cocrystallisation, pharmaceutical aspects, metal complexes (including metal–organic frameworks), supramolecular aspects and characterization methods. The historical development, mechanistic aspects, limitations and opportunities are also discussed (314 references).

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Mechanochemistry: opportunities for new and cleaner synthesis

인공고관절의 세라믹 볼 헤드의 기계적 안정성 평가를 위한 3 차원 유한요소 해석

Interpretation of X-ray Powder Diffraction Patterns . By H. Lipson and H. Steeple. Pp. viii + 335 + 3 plates. (Mac-millan: London; St Martins Press: New York, May 1970.) £4.

X-Ray Diffraction

Preceramic polymers were proposed over 30 years ago as precursors for the fabrication of mainly Si-based advanced ceramics, generally denoted as polymer-derived ceramics (PDCs). The polymer to ceramic transformation process enabled significant technological breakthroughs in ceramic science and technology, such as the development of ceramic fibers, coatings, or ceramics stable at ultrahigh temperatures (up to 2000°C) with respect to decomposition, crystallization, phase separation, and creep. In recent years, several important advances have been achieved such as the discovery of a variety of functional properties associated with PDCs. Moreover, novel insights into their structure at the nanoscale level have contributed to the fundamental understanding of the various useful and unique features of PDCs related to their high chemical durability or high creep resistance or semiconducting behavior. From the processing point of view, preceramic polymers have been used as reactive binders to produce technical ceramics, they have been manipulated to allow for the formation of ordered pores in the meso-range, they have been tested for joining advanced ceramic components, and have been processed into bulk or macroporous components. Consequently, possible fields of applications of PDCs have been extended significantly by the recent research and development activities. Several key engineering fields suitable for application of PDCs include high-temperature-resistant materials (energy materials, automotive, aerospace, etc.), hard materials, chemical engineering (catalyst support, food- and biotechnology, etc.), or functional materials in electrical engineering as well as in micro/nanoelectronics. The science and technological development of PDCs are highly interdisciplinary, at the forefront of micro- and nanoscience and technology, with expertise provided by chemists, physicists, mineralogists, and materials scientists, and engineers. Moreover, several specialized industries have already commercialized components based on PDCs, and the production and availability of the precursors used has dramatically increased over the past few years. In this feature article, we highlight the following scientific issues related to advanced PDCs research: (1) General synthesis procedures to produce silicon-based preceramic polymers.
(2) Special microstructural features of PDCs.
(3) Unusual materials properties of PDCs, that are related to their unique nanosized microstructure that makes preceramic polymers of great and topical interest to researchers across a wide spectrum of disciplines.
(4) Processing strategies to fabricate ceramic components from preceramic polymers.
(5) Discussion and presentation of several examples of possible real-life applications that take advantage of the special characteristics of preceramic polymers. Note: In the past, a wide range of specialized international symposia have been devoted to PDCs, in particular organized by the American Ceramic Society, the European Materials Society, and the Materials Research Society. Most of the reviews available on PDCs are either not up to date or deal with only a subset of preceramic polymers and ceramics (e.g., silazanes to produce SiCN-based ceramics). Thus, this review is focused on a large number of novel data and developments, and contains materials from the literature but also from sources that are not widely available.

Polymer-Derived Ceramics: 40 Years of Research and Innovation in Advanced Ceramics

Metallurgical recovery of metals from electronic waste: a review.

Mechanochemical synthesis of lead selenide PbSe nanoparticles has been performed by high-energy milling of lead and selenium powder in a planetary ball mill Pulverisette 6 (Fritsch, Germany) and in an industrial eccentric vibratory mill ESM 654 (Siebtechnik GmbH, Germany) Structural properties of the synthesized lead selenide were characterized by X-ray diffraction, which confirms crystalline nature of PbSe nanoparticles (JCPDS 6-354) The average size of PbSe crystallites of 37 nm was calculated from XRD data by Williamson-Hall method The methods of particle size distribution analysis, specific surface area measurement, scanning electron microscopy and transmission electron microscopy were used for characterization of surface, mean particle size, and morphology of PbSe An application of industrial mill verified a possibility of the synthesis of a narrowband-gap semiconductor PbSe at ambient temperature and in a relatively short reaction time

Mechanochemical synthesis of nanocrystalline lead selenide

Mechanochemical Preparation of Nanocrystalline Stannite/Chatkalite Composite: Kinetics of Synthesis and Thermoelectric Properties

The Interoceanmetal Joint Organization’s (IOM) exploration license is granted in the area located within the Clarion–Clipperton Zone of the Eastern Central Pacific. All activities related to exploration of minerals in this area are beyond the limits of national jurisdiction and come under the provision of the United Nations Convention on the Law of the Sea and related regulations. The geological survey, which was the subject of the exploration, focused on the polymetallic nodule deposits. Other activities covered the tests of nodule processing, including alternative methods of metal extraction. This article describes the methodology of the bioleaching process and provides a summary of the initial results of the bioleaching test, applied to the samples of polymetallic nodules taken from the H22 exploration block of the IOM exploration area. The bioleaching efficiency under different pulp density conditions was studied. The enrichment of heterotrophic Mn-reducing microorganisms was prepared as the leaching medium. Bioleaching of the samples took place with different sample weights in order to determine the maximum possible extraction yield and the highest concentration of elements obtained in the leachate. During the bioleaching, the media were also exchanged to achieve maximum polymetallic nodule decomposition with regular addition of nutrients for heterotrophic Mn-reducing bacteria. The bioleaching efficiency of the polymetallic nodules increased to 100% (without Cu) when the pulp density was reduced to 0.1% (w/v). The discontinuous bioleaching and washing process recovered 55% Mn, 36% Ni, 15% Co, 27% Zn, and 38% Cu when the pulp density was increased to 10% (w/v). To achieve total Mn, Cu, Zn, Co, and Ni recovery from the polymetallic nodules, an intermittent bioleaching with about 25 changes of 60% of the medium was required when the pulp density was increased to 10% (w/v). Bioleaching has the potential to be used as an environmentally friendly alternative to other commonly used options for leaching and processing.

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Bioleaching Test of Polymetallic Nodule Samples from the IOM Exploration Area

Magnetic Properties of Mechanochemically Synthesized Mixed Oxides N.G. Kostova, A. Zorkovskab,∗, J. Kova£, N. Velinov, P. Balao Institute of Catalysis, Bulgarian Academy of Sciences, acad. G. Bonchev, Bl. 11, 1 1113 So a, Bulgaria Institute of Geotechnics Slovak Academy of Sciences, Watsonova 45, 043 53 Ko2ice, Slovakia The mixed oxides Fe2O3-ZnO have been obtained in nanocrystalline state by reactive milling in a high-energy planetary mill, from a stoichiometric mixture of hematite and ZnO. The magnetic properties of samples were evaluated by magnetization measurements and Mossbauer spectrometry. A post milling annealing promotes the solid state reaction and improves the zinc ferrite formation, paramagnetic ZnFe2O4 phase is formed. Further mechanical activation leads to structural transformation into Wustite-type (FeZn)O mixed oxide, with ferromagnetic hysteresis and increased magnetization.

http://przyrbwn.icm.edu.pl/APP/PDF/126/a126z1p199.pdf

Magnetic Properties of Mechanochemically Synthesized Mixed Oxides

Magnetic nanoparticles consisting of magnetite (Fe 3 O 4 ) are promising therapeutic and/or diagnostic tools in medicine. In this chapter, the ball milling processing of natural mineral magnetite for medical applications is described. The chapter is focused on the preparation of bifunctional materials where magnetic component (Fe 3 O 4 ) is combined with fluorescent (ZnS) and therapeutic (As 4 S 4 ) entities. The properties of the prepared powder materials including microstructure characterization are described in details. Subsequently, the coating with biocompatible surfactants is presented. The physico-chemical properties including stability are also demonstrated. Finally, the possibilities of up-scaling the process is described referring to the latest knowledge regarding to this issue.

Peter Baláž

Papers

Mechanochemical synthesis of nanocrystalline lead selenide

Mechanochemical Preparation of Nanocrystalline Stannite/Chatkalite Composite: Kinetics of Synthesis and Thermoelectric Properties

Bioleaching Test of Polymetallic Nodule Samples from the IOM Exploration Area

Magnetic Properties of Mechanochemically Synthesized Mixed Oxides

Processing of natural mineral magnetite for medical applications