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Hsu, Stephen M.; Zhang, Jun; Yin, Zhanfeng

doi:10.1023/a:1020112901674

Cited by 104 publications

(40 citation statements)

References 12 publications

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“…82,83 Regarding the new surfaces generated by fracture, numerical findings suggest that they can exhibit a marked chemical reactivity due to the chemical bond unsaturation. However, the chemical reactivity is rapidly quenched by the relaxation processes, resulting in surface reconstruction and chemical reaction with the environment.…”

Section: Friction Wear and Fracturementioning

confidence: 99%

Hallmarks of mechanochemistry: from nanoparticles to technology

et al. 2013

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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).

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Section: Friction Wear and Fracturementioning

confidence: 99%

Hallmarks of mechanochemistry: from nanoparticles to technology

et al. 2013

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“…During sliding process, total area (S) of nascent surface generated by friction can be calculated by the equation (5).…”

Section: Desorption Amount Of Reaction Productsmentioning

confidence: 99%

“…It is regarded that there are two main causes for tribochemistry: (1) thermal and pressure effects at mechanical contacts, i.e., high temperature and pressure at the contact area, (2) enhanced activity of contacting surfaces, for example, nascent surfaces and emissions [1][2][3][4][5]. Under boundary lubrication conditions, the surface layers on solids such as metal oxides and organic contaminants are removed by mechanical stimulation, resulting in the formation of nascent surfaces.…”

Section: Introductionmentioning

confidence: 99%

Investigation of decomposition of hydrocarbon oil on the nascent surface of steel

et al. 2007

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Hydrocarbon oil with low vapor pressure has been used as a lubricant in high-vacuum conditions. Decomposition of the oil under boundary lubrication conditions was studied by investigating desorption of hydrogen and hydrocarbons, generated by tribochemical reaction occurred on nascent surface of 52100 steel during the sliding process in a ball-on-disk type sliding tester. Gaseous products by tribochemical decomposition were monitored by a quadrupole mass spectrometer (Q-MS), which would reveal the decomposition mechanism of hydrocarbon oil. It is found that tribochemical reactions of hydrocarbon oil occurred on active sites on steel generated by sliding, the desorption amount of hydrogen and gaseous hydrocarbons increased linearly with sliding velocity, and parabolically with load. A critical load for the activation of decomposition of the hydrocarbon oil on bearing steel was found to be about 1.1 N. In this paper, the decomposition mechanism of hydrocarbon oil was also explored.

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“…Specifically, lubricants undergo reactions, called tribochemical reactions, in response to the extreme stresses and temperatures experienced in sliding contacts. [9][10][11][12][13] In many cases, these reactions have a negative effect on the performance of the lubricant by leading to its decomposition as well as corrosion and wear of surface materials. 11,[14][15][16] However, tribochemical reactions can be useful in some cases, with studies suggesting that compression-induced changes in the coordination numbers of zinc atoms in protective films contribute to lubrication in autoa) Electronic mail: nicholas.mosey@chem.queensu.ca.…”

Section: Introductionmentioning

confidence: 99%

Chemical response of aldehydes to compression between (0001) surfaces of α-alumina

Haw

Mosey

2011

The Journal of Chemical Physics

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First-principles molecular dynamics simulations are used to investigate the chemical response of acetaldehyde molecules (MeCHO) to compression and decompression between (0001) surfaces of α-alumina (Al(2)O(3)), with pressures reaching approximately 40 GPa. The results demonstrate that the MeCHO molecules are transformed into other chemical species through a range of chemical processes involving the formation of C-O and C-C bonds between MeCHO monomers as well as proton transfer. The mechanistic details of a representative set of the observed reactions are elucidated through analysis of maximally localized Wannier functions. Analysis of the changes in structure demonstrates that the main role of compression is to reduce the distances between MeCHO molecules to facilitate the formation of C-O bonds. Additional examination of the electronic structure demonstrates that the surface plays a role in facilitating proton transfer by both rendering hydrogen atoms in adsorbed MeCHO molecules more acidic and by acting as a proton acceptor. In addition, adsorption of the MeCHO molecules on the surface renders the sp(2) carbon atoms in these molecules more electrophilic, which promotes the formation of C-C and C-O bonds. It is suggested that the reaction products may be beneficial in the context of wear inhibition. Comparison of the surface structure before compression and after decompression demonstrates that the aldehydes and reaction products are capable of inhibiting irreversible changes in the structure as long as there is at least a monolayer coverage of these species. As a whole, the study sheds light on the chemical behavior of the aldehydes in response to uniaxial compression in nanoscopic contacts that likely applies to other molecules containing carbonyl groups and other metal oxide surfaces.

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Cited by 104 publications

References 12 publications

Hallmarks of mechanochemistry: from nanoparticles to technology

Hallmarks of mechanochemistry: from nanoparticles to technology

Investigation of decomposition of hydrocarbon oil on the nascent surface of steel

Chemical response of aldehydes to compression between (0001) surfaces of α-alumina

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