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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Hallmarks of mechanochemistry: From nanoparticles to technology

Wieslaw J. Roth,†,∥ Petr Nachtigall,‡ Russell E. Morris, and Jirí̌ Čejka*,† †J. Heyrovsky ́ Institute of Physical Chemistry, Academy of Sciences of the Czech Republic, v.v.i., Dolejsǩova 3, CZ-182 23 Prague 8, Czech Republic ‡Department of Physical and Macromolecular Chemistry, Faculty of Science, Charles University in Prague, Hlavova 2030, Prague 2, 128 00, Czech Republic EaStCHEM School of Chemistry, University of St. Andrews, St. Andrews KY16 9ST, Scotland Faculty of Chemistry, Jagiellonian University in Krakoẃ, ul. Ingardena 3,30-060 Krakoẃ, Poland

Two-dimensional zeolites: current status and perspectives.

Site Heterogeneous Catalysts: Strategies, Methods, Structures, and Activities Christophe Copeŕet,*,† Aleix Comas-Vives,† Matthew P. Conley,† Deven P. Estes,† Alexey Fedorov,† Victor Mougel,† Haruki Nagae,†,‡ Francisco Nuñ́ez-Zarur,† and Pavel A. Zhizhko†,§ †Department of Chemistry and Applied Biosciences, ETH Zürich, Vladimir Prelog Weg 1−5, CH-8093 Zürich, Switzerland ‡Department of Chemistry, Graduate School of Engineering Science, Osaka University, CREST, Toyonaka, Osaka 560-8531, Japan A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilov str. 28, 119991 Moscow, Russia

Surface Organometallic and Coordination Chemistry toward Single-Site Heterogeneous Catalysts: Strategies, Methods, Structures, and Activities

Silica Surface Features and Their Role in the Adsorption of Biomolecules: Computational Modeling and Experiments / Albert Rimola;Dominique Costa;Mariona Sodupe;Jean-François Lambert;Piero Ugliengo. In: CHEMICAL REVIEWS. ISSN 0009-2665. STAMPA. 113:6(2013), pp. 4216-4313. Original Citation: Silica Surface Features and Their Role in the Adsorption of Biomolecules: Computational Modeling and Experiments

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Silica Surface Features and Their Role in the Adsorption of Biomolecules: Computational Modeling and Experiments

We report our study of a silica-water interface using reactive molecular dynamics. This first-of-its-kind simulation achieves length and time scales required to investigate the detailed chemistry of the system. Our molecular dynamics approach is based on the ReaxFF force field of van Duin et al. [J. Phys. Chem. A 107, 3803 (2003)]. The specific ReaxFF implementation (SERIALREAX) and force fields are first validated on structural properties of pure silica and water systems. Chemical reactions between reactive water and dangling bonds on a freshly cut silica surface are analyzed by studying changing chemical composition at the interface. In our simulations, reactions involving silanol groups reach chemical equilibrium in approximately 250 ps. It is observed that water molecules penetrate a silica film through a proton-transfer process we call "hydrogen hopping," which is similar to the Grotthuss mechanism. In this process, hydrogen atoms pass through the film by associating and dissociating with oxygen atoms within bulk silica, as opposed to diffusion of intact water molecules. The effective diffusion constant for this process, taken to be that of hydrogen atoms within silica, is calculated to be 1.68 x 10(-6) cm(2)/s. Polarization of water molecules in proximity of the silica surface is also observed. The subsequent alignment of dipoles leads to an electric potential difference of approximately 10.5 V between the silica slab and water.

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A reactive molecular dynamics simulation of the silica-water interface

Realistic Models of Hydroxylated Amorphous Silica Surfaces and MCM‐41 Mesoporous Material Simulated by Large‐scale Periodic B3LYP Calculations

A partial charge shell-ion model potential for silica polymorphs and their hydroxylated surfaces (FFSiOH) was parametrized in a self-consistent way using periodic B3LYP results for bulk α-cristobalite and the (100) and (001) hydroxylated surfaces. The reliability of the new potentials was checked by comparing structures, vibrational frequencies and relative phase stabilities of dense bulk silica polymorphs, namely α-quartz, α-cristobalite, α-tridymite, and Stishovite with both experimental and B3LYP data. The FFSiOH was also checked for computing structural and vibrational features of representative all-silica microporous materials, namely edingtonite, chabazite, and faujasite. As a last step, FFSiOH was adopted to predict OH stretching vibrational frequencies and relative thermodynamic stability of the most common fully hydroxylated surfaces of the dense silica polymorphs, the (100) and (001) faces of all-silica edingtonite, the features of the local Si-defect in chabazite and sodalite known as (SiOH)4 h...

FFSiOH: a New Force Field for Silica Polymorphs and Their Hydroxylated Surfaces Based on Periodic B3LYP Calculations

Different models of hydroxylated surfaces of quartz, cristobalite, and tridymite have been studied with the hybrid B3LYP functional using the Gaussian basis set of polarized double-ζ quality with periodic boundary conditions. Starting from the optimized bulk structures of the polymorphs, 2D slabs exhibiting low (hkl) crystallographic planes have been cut, dangling bonds healed by hydroxyl groups, and the final structures fully optimized. The H-bond pattern at a given surface depends on the (hkl) plane and on the OH group density, exhibiting isolated, weakly interacting pairs, short chains, or strings extending through the whole surface. Cases in which no H-bonds are present envisage either a very low OH density or slab structural rigidity which hinders the OH groups to establish H-bond contacts. The thermodynamics of surface hydroxylation of the considered polymorphs has been shown to correlate with the strength of the H-bonds formed at the surfaces measured by the bathochromic shift of the ν(OH) stretchi...

H-Bond Features of Fully Hydroxylated Surfaces of Crystalline Silica Polymorphs: A Periodic B3LYP Study

Silica and silica based materials are widely used in chemistry and materials science due to their importance in many technological fields. The properties of these materials, which are crucial for their applications, are mainly determined by the presence of hydrogen bonding between surface silanols. Here, we present ab initio molecular dynamics simulations (AIMD) on different surfaces derived from the crystallographic α-quartz (100) and the α-cristobalite (001) and (101) faces, both free and at the interface with liquid water. The focus was on studying whether water adsorption can disrupt the H-bond pattern at the pristine free silica surface and how deep the perturbation due to the contact with the surface affects the structure of the water multilayer. Results highlight that the water phase is over structured at the interface with silica, as compared to water bulk. Furthermore, an apparent counterintuitive behavior has been observed for quartz (100) and cristobalite (001) surfaces: the interaction with water does not cleave the pre-existent H-bonds between the surface silanol groups. On the contrary, in several cases, it is observed that SiOH⋯OHSi H-bonds are even strengthened, as the result of a mutual cooperative H-donor/H-acceptor enhancement between silanols and water molecules, which may alter the adsorption capability of these silica surfaces.

Cooperative effects at water–crystalline silica interfaces strengthen surface silanol hydrogen bonding. An ab initio molecular dynamics study

Periodic DFT (BLYP, B3LYP, and BHandHLYP) calculations have been used to study the properties of SiO• radical defect on quartz, cristobalite, tridymite, and amorphous surface models. Crystalline orbitals are constructed by an expansion of Gaussian type orbitals in which all atoms are represented with a double-ζ plus polarization quality basis set. Starting from fully hydroxylated 2D slab models, the radical defect is constructed by removing a hydrogen atom from a silanol of the surface while conserving the other features of the crystalline polymorph. Among the different functionals used, the hybrid BHandHLYP is the one that better compares to the experimental EPR data and provides reaction energies in better agreement with CCSD(T). The GGA BLYP functional, however, tends to delocalize the spin density, which can have important consequences on the H-bonding at the surface, especially when it exhibits geminal silanols. Comparison between the hydroxylated and the radical slab shows that the radical defect at...

Federico Musso

Papers

Realistic Models of Hydroxylated Amorphous Silica Surfaces and MCM‐41 Mesoporous Material Simulated by Large‐scale Periodic B3LYP Calculations

FFSiOH: a New Force Field for Silica Polymorphs and Their Hydroxylated Surfaces Based on Periodic B3LYP Calculations

H-Bond Features of Fully Hydroxylated Surfaces of Crystalline Silica Polymorphs: A Periodic B3LYP Study

Cooperative effects at water–crystalline silica interfaces strengthen surface silanol hydrogen bonding. An ab initio molecular dynamics study

Periodic DFT Study of Radical Species on Crystalline Silica Surfaces