TY - CONF A1 - de Oliveira Guilherme Buzanich, Ana A1 - Michalchuk, Adam A1 - Cakir, Cafer Tufan A1 - Haider, M. B. A1 - Yusenko, Kirill A1 - Radtke, Martin A1 - Reinholz, U. A1 - Emmerling, Franziska T1 - Time resolved in situ monitoring of mechanochemical transformations by X-ray spectroscopy (XAS) N2 - Mechanochemical reactions promise a new direction for environmentally benign preparation of materials, and has been dubbed by IUPAC as one of the 10 chemical innovations that will change our world. Despite this significant promise, very little is known about the mechanisms that drive mechanochemical transformations, posing significant barriers to realizing their full potential. To this end, there is growing need to follow mechanochemical reactions in situ and in real time. We here describe advances in the development and application of XAS methods to monitor material synthesis in real time under mechanochemical conditions. We demonstrate the generality of our approaches by describing mechanochemical syntheses of materials by both vibratory ball milling and by Resonant Acoustic Mixing (RAM), where a time resolution of 1 second is for a whole XAS spectrum was achieved. Moreover, we describe how spectroscopic methods can be coupled to diffraction-based approaches, thereby providing new dimensions in understanding mechanochemical synthesis. T2 - AfLS3 CY - Online meeting DA - 14.11.2021 KW - Dipsersive XAS KW - Mechanochemistry KW - Time-resolved KW - In situ PY - 2021 AN - OPUS4-56256 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - de Oliveira Guilherme Buzanich, Ana A1 - Michalchuk, Adam A1 - Cakir, Cafer Tufan A1 - Yusenko, Kirill A1 - Radtke, Martin A1 - Reinholz, U. A1 - Emmerling, Franziska T1 - Time resolved in situ monitoring of mechanochemical transformations by X-ray spectroscopy (XAS) N2 - Mechanochemical reactions promise a new direction for environmentally benign preparation of materials, and has been dubbed by IUPAC as one of the 10 chemical innovations that will change our world. Despite this significant promise, very little is known about the mechanisms that drive mechanochemical transformations, posing significant barriers to realizing their full potential. To this end, there is growing need to follow mechanochemical reactions in situ and in real time. We here describe advances in the development and application of XAS methods to monitor material synthesis in real time under mechanochemical conditions. We demonstrate the generality of our approaches by describing mechanochemical syntheses of materials by both vibratory ball milling and by Resonant Acoustic Mixing (RAM), where a time resolution of 1 second is for a whole XAS spectrum was achieved. Moreover, we describe how spectroscopic methods can be coupled to diffraction-based approaches, thereby providing new dimensions in understanding mechanochemical synthesis. T2 - Denver X-ray Conference: DXC 2021 CY - Online meeting DA - 02.08.2021 KW - Dispersive XAS KW - Mechanochemistry KW - Time resolved KW - In situ PY - 2021 AN - OPUS4-56257 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Emmerling, Franziska A1 - Martins, Ines T1 - Carbamazepine Dihydroxybenzoic Acid Cocrystals: Exploring Packing Interactions and Reaction Kinetics JF - Crystal Growth and Design N2 - Herein, we present the mechanochemical formation of three new cocrystals containing the active pharmaceutical ingredient carbamazepine and dihydroxybenzoic acids as coformers (CBZ:2,4-DHBA 1:1, CBZ:2,5-DHBA 1:1, and CBZ:2,6-DHBA 1:1). Rietveld methods were used for three different purposes: (i) refining all structures solved using powder X-ray diffraction, (ii) performing a quantitative phase analysis of the diffraction data collected from ex situ mechanochemical reactions at different milling times, and (iii) determining the cocrystallization kinetic profiles. The rate of cocrystallization was found to be higher for the formation of CBZ:2,4-DHBA and CBZ:2,6-DHBA, reaching an equilibrium after 600 s of milling. In the case of CBZ:2,5-DHBA a short induction period of 20 s was detected prior to the start of the reaction and an equilibrium was reached after 1200 s. An empirical trend between the rate of cocrystallization and the structural complexity of the cocrystal product was found. The slowest cocrystallization rate observed for CBZ:2,5-DHBA corresponds to the crystal structure deviating substantially from the hydrogen-bonding motif found in the reactants. KW - Mechanochemistry KW - In situ real-time monitoring KW - Kinetics PY - 2021 DO - https://doi.org/10.1021/acs.cgd.1c00902 VL - 21 IS - 12 SP - 6961 EP - 6970 PB - ACS Publications AN - OPUS4-54407 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Casali, L. A1 - Broll, V. A1 - Ciurili, S. A1 - Braga, D. A1 - Emmerling, Franziska A1 - Gepioni, F. T1 - Facilitating Nitrification Inhibition through Green, Mechanochemical Synthesis of a Novel Nitrapyrin Complex JF - Crystal Growth and Design N2 - Nitrapyrin (NP) is applied to cultivated soils to inhibit the enzymatic activity of ammonia monooxygenase (AMO), but its poor aqueous solubility and high volatility severely limit its application. β-Cyclodextrin (β-CD) is commonly used to form inclusion complexes with hydrophobic molecules, improving water solubility and stability upon complexation. Here we report on the mechanochemical synthesis of the inclusion complex β-CD·NP, characterized via a combination of solid-state techniques, including exsitu and in situ X-ray diffraction, Raman and NMR spectroscopies, transmission electron microscopy, and energy dispersive X-ray spectroscopy. The pure inhibitor NP was also structurally characterized. The β-CD·NP complex presents improved solubility and thermal stability, and still inhibits the enzymatic activity of AMO with high efficacy. All results indicate that the inclusion of NP into β-CD represents a viable route for the preparation of a novel class of inhibitors, with improved properties related to stability, water solubility, and good inhibition activity. KW - Mechanochemistry KW - Nitrification PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-537154 DO - https://doi.org/10.1021/acs.cgd.1c00681 VL - 21 IS - 10 SP - 5792 EP - 5799 PB - ACS Publications AN - OPUS4-53715 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Emmerling, Franziska T1 - Shaken not stirred: enhancing the flavor of mechanochemistry N2 - Mechanochemistry is increasingly used for synthesizing soft matter materials including metal organic compounds and cocrystals.1 The ever-increasing interest in this method is contrasted by a limited mechanistic understanding of the mechanochemical reactivity and selectivity. Time-resolved in situ investigations of milling reactions provide direct insights in the underlying mechanisms.2-4 We recently introduced different setups enabling in situ investigation of mechanochemical reactions using synchrotron XRD combined with Raman spectroscopy and thermography. The presented setup allows the detection of crystalline, amorphous, eutectic, and liquid intermediates. Furthermore, the chemical composition of the reaction mixture was found to be directly correlated with changes in the temperature profile of the reaction. The resulting deeper kinetic and thermodynamic understanding of milling processes is the key for future optimization of mechanochemical syntheses. In this contribution, we will discuss our recent results investigating the formation of (polymorphic) cocrystals and coordination polymers.2,3,5 Our results indicate that in situ investigation of milling reactions offer a new approach to tune and optimize mechanochemical syntheses. T2 - BCA/BACG joint spring meeting CY - Online meeting DA - 29.03.2021 KW - Mechanochemistry KW - Cocrystals KW - Crystal Engineering PY - 2021 AN - OPUS4-53995 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Emmerling, Franziska T1 - Shaken not stirred: in situ investigations of mechanochemical processes N2 - Mechanochemistry has emerged as one of the most interesting synthetic protocols to produce new materials. The development of mechanochemistry as a synthetic method is supported by excellent research by many groups worldwide in a wide range of applications. The potential of mechanochemistry is also reflected in the inclusion in IUPAC’s 10 chemical innovations that will change our world’.[1] Solvent-free methodologies lead to unique chemical processes during synthesis with the consequent formation of martials with new properties.2 In this contribution, we will discuss our recent results investigating the formation of (polymorphic) cocrystals, coordination polymers, metal oxides and metal nanoparticles.[3-8] We introduced different setups enabling in situ investigation of mechanochemical reactions using synchrotron XRD combined with Raman spectroscopy and thermography. T2 - Deutsche Kristallzüchtertagung CY - Berlin, Germany DA - 06.10.2021 KW - Mechanochemistry KW - In situ real-time monitoring KW - Crystal PY - 2021 AN - OPUS4-53996 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lampronti, G. A1 - Michalchuk, Adam A1 - Mazzeo, P. A1 - Belenguer, Ana A1 - Sanders, J. K. M. A1 - Bacchi, A. A1 - Emmerling, Franziska T1 - Changing the game of time resolved X-ray diffraction on the mechanochemistry playground by downsizing JF - Nature Communications N2 - Time resolved in situ (TRIS) monitoring has revolutionised the study of mechanochemical transformations but has been limited by available data quality. Here we report how a combination of miniaturised grinding jars together with innovations in X-ray powder diffraction data collection and state-of-the-art analysis strategies transform the power of TRIS synchrotron mechanochemical experiments. Accurate phase compositions, comparable to those obtained by ex situ measurements, can be obtained with small sample loadings. Moreover, microstructural parameters (crystal size and microstrain) can be also determined with high confidence. This strategy applies to all chemistries, is readily implemented, and yields high-quality diffraction data even using a low energy synchrotron source. This offers a direct avenue towards the mechanochemical investigation of reactions comprising scarce, expensive, or toxic compounds. Our strategy is applied to model systems, including inorganic, metal-organic, and organic mechanosyntheses, resolves previously misinterpreted mechanisms in mechanochemical syntheses, and promises broad, new directions for mechanochemical research. KW - Mechanochemistry KW - Synchrotron radiation KW - Material synthesis PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-535932 DO - https://doi.org/10.1038/s41467-021-26264-1 SN - 2041-1723 VL - 12 IS - 1 SP - 1 EP - 9 PB - Nature Publishing Group CY - London AN - OPUS4-53593 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rautenberg, Max A1 - Gernhard, Marius A1 - Low, Jian L. A1 - Paulus, Beate A1 - Roth, Christina A1 - Emmerling, Franziska T1 - The Effect of Fluorine on Catalysts for the Oxygen Reduction Reaction obtained from Metal Organic Frameworks N2 - The oxygen reduction reaction (ORR) – an important reaction in electrochemical devices, such as fuel cells - is characterized by its sluggish kinetics and therefore requires catalysis. The industry currently relies on platinum as a catalyst, although it is scarce and expensive, hindering the commercial breakthrough of fuel cells in automotive applications. Platinum-free catalysts on basis of nitrogen- and metal doped carbons (NMCs) and fluorinated carbons are promising materials to replace platinum-based catalysts for the ORR. In this work we prepared six metal-organic frameworks (MOFs) by mechanical ball mill grinding and studied their formation by in-situ powder X-ray diffraction. Furthermore, the samples were carbonized under controlled conditions (900°C, 1h, N2-atmosphere) to yield carbon materials, that were employed in ORR-electrocatalysis. The effect of Co-doping and fluorination was systematically studied and outstanding ORR activity was found for the catalyst prepared from the Co-doped fluorinated ZIF-8. T2 - International Symposium on Fluorine-specific interactions CY - Berlin, Germany DA - 27.09.2021 KW - PGM-free catalyst KW - Oxygen Reduction Reaction KW - Mechanochemistry KW - MOFs PY - 2021 AN - OPUS4-53533 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rautenberg, Max A1 - Gernhard, Marius A1 - Roth, Christina A1 - Emmerling, Franziska T1 - Fluorination and co-doping of ZIF-8 by ball mill grinding for efficient oxygen reduction electrocatalysis N2 - The oxygen reduction reaction (ORR) is a common process in a variety of electrochemical devices, like fuel cells and metal air batteries. The sluggish kinetics of the ORR require an electrocatalyst to pass this bottleneck.[1] Currently, the most used catalytical systems are platinum-based, with several drawbacks, such as the high cost, low availability, and deactivation by CO poisoning.[2] Efforts are made to develop efficient, durable and low cost catalysts to promote the commercialization of fuel cells. Non-precious metal catalysts are promising candidates for efficient ORR catalysis. It has been shown that pyrolyzing metal organic frameworks (MOFs) under inert conditions yields carbon-rich materials, with evenly distributed metal sites, which possess promising electrocatalytic activity.[3] One widely used type of MOF as ORR catalyst precursors is the zeolitic imidazole framework (ZIF) where metal cations are linked through imidazole-based ligands. Their porous nature is partially retained after carbonization, making MOFs very suitable precursor materials. Herein we report the mechanochemical synthesis and structural analysis of Co-doped ZIF-8 (Zn), as well as two polymorphs (dense and prorous) of fluorinated Co-doped CF3-ZIF-8 (Zn). The samples showed electrochemical performance comparable to platinum after carbonization for 1 h at temperatures ranging between 850 – 1000°C. T2 - XXV General Assembly and Congress of the International Union of Crystallography - IUCr 2021 CY - Prague, Czech Republic DA - 14.08.2021 KW - PGM-free catalyst KW - Oxygen Reduction Reaction KW - Mechanochemistry KW - MOFs PY - 2021 AN - OPUS4-53535 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rautenberg, Max T1 - Coordination Polymers for the Applications in Electrochemical Devices N2 - Coordination polymers can be used as sacrificial templates to prepare nitrogen- and metal doped carbons (NMCs), which are promising catalysts for the oxygen reduction reaction. We at BAM employ mechanochemistry as a "green" synthetic approach to coordiantion polymers, which are throroughly characterized by methods such as XRD, XPS and sorption studies. Our collaborators can prepare NMCs from our coordination polymers and assess the catalytic activity thereof. T2 - 3rd Training School: "Mechanochemistry: from supramolecular to covalent bonds - synthesis and strctural characterization CY - Lisbon, Portugal DA - 22.03.2021 KW - PGM-free catalyst KW - Mechanochemistry KW - MOFs KW - Electrocatalysis KW - Oxygen reduction reaction (ORR) PY - 2021 AN - OPUS4-53536 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rautenberg, Max A1 - Gernhard, Marius A1 - Low, Jian L. A1 - Roth, Christina A1 - Paulus, Beate A1 - Emmerling, Franziska T1 - Fluorine Modified ZIF 8 for Electrochemical Catalysis: Where does the Fluorine go? N2 - Carbonization of fluorinated metal-organic frameworks (MOFs) should yield fluorinated nitrogen- and metal-doped carbons (F-NMCs), which are a combination of NMCs and fluorinated carbons, each promising electrocatalysts on their own. We synthesized two polymorphs of a fluorinated MOF by mechanical ball mill grinding, and carbonized them to yield potential electrocatalyt materials. The catalytical activity towards the oxygen reduction reaction (ORR) was examined, finding good activites. Simulations from a theoretic model helped assesing the stability of proposed catalytic sites and understanding the measured activites towards the ORR catalysis. T2 - Online symposium of the CRC 1349 "fluorine-specific interactions" CY - Online meeting DA - 29.06.2021 KW - PGM-free catalyst KW - Oxygen Reduction Reaction KW - Mechanochemistry KW - MOFs KW - Computational chemistry PY - 2021 AN - OPUS4-53538 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rautenberg, Max A1 - Gernhard, Marius A1 - Roth, Christina A1 - Emmerling, Franziska T1 - Synthesis and characterization of fluorinated Co-Zn-Zeolitic imidazole frameworks for catalysis of the oxygen reduction reaction N2 - The oxygen reduction reaction (ORR) is a common process in a variety of electrochemical devices, like fuel cells and metal air batteries. The sluggish kinetics of the ORR require an electrocatalyst to pass this bottleneck.[1] Currently, the most used catalytical systems are platinum-based, with several drawbacks, such as the high cost, low availability, and deactivation by CO poisoning.[2] Efforts are made to develop efficient, durable and low cost catalysts to promote the commercialization of fuel cells. Non-precious metal catalysts are promising candidates for efficient ORR catalysis. It has been shown that pyrolyzing metal organic frameworks (MOFs) under inert conditions yields carbon-rich materials, with evenly distributed metal sites, which possess promising electrocatalytic activity.[3] One widely used type of MOF as ORR catalyst precursors is the zeolitic imidazole framework (ZIF) where metal cations are linked through imidazolebased ligands. Herein we report the mechanochemical synthesis, structural analysis and of Co-doped ZIF-8 (Zn), as well as its fluorinated counterpart Co-doped CF3 -ZIF-8 (Zn). The samples showed electrochemical performance comparable to platinum after carbonization for 1h at temperatures ranging between 850 – 1000°C. T2 - 15th International conference on materials chemistry (MC15) CY - Online meeting DA - 12.07.2021 KW - PGM-free catalyst KW - Oxygen Reduction Reaction KW - Mechanochemistry KW - MOFs PY - 2021 AN - OPUS4-53539 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Martins, I. A1 - Carta, M. A1 - Haferkamp, Sebastian A1 - Feiler, Torvid A1 - Delogu, F. A1 - Colacino, E. A1 - Emmerling, Franziska T1 - Mechanochemical N‑Chlorination Reaction of Hydantoin: In Situ Real-Time Kinetic Study by Powder X‑ray Diffraction and Raman Spectroscopy JF - Acs Sustainable Chemistry & Engineering N2 - Mechanochemistry has become a valuable tool for the synthesis of new molecules, especially in the field of organic chemistry. In the present work, we investigate the kinetic profile of the chlorination reaction of N-3-ethyl-5,5-dimethylhydantoin (EDMH) activated and driven by ball milling. The reaction has been carried out using 2 mm, 4 mm, 5 mm, 6 mm, and 8 mm ball sizes in a new small custom-made Perspex milling jar. The Crystal structure of the starting material EDMH and the 1-chloro-3-ethyl5,5′-dimethyl hydantoin (CEDMH) chlorination product was solved by single-crystal X-ray diffraction. The reaction was monitored, in situ and in real time, by both powder X-ray diffraction (PXRD) and Raman spectroscopy. Our kinetic data show that the reaction progress to equilibrium is similar at all milling ball sizes. The induction period is very short (between 10 and 40 s) when using 4 mm, 5 mm, 6 mm, and 8 mm balls. For the reaction performed with a 2 mm ball, a significantly longer induction period of 9 min was observed. This could indicate that an initial energy accumulation and higher mixing efficiency are necessary before the reaction starts. Using different kinetic models, we found that the amount of powder affected by critical loading conditions during individual impacts is significantly dependent on the ball size used. An almost linear correlation between the rate of the chemical transformations and the ball volume is observed. KW - Mechanochemistry KW - In situ real-time monitoring KW - N-Chlorination KW - Kinetics KW - Hydantoin KW - Powder X-ray diffraction KW - Raman spectroscopy PY - 2021 DO - https://doi.org/10.1021/acssuschemeng.1c03812 VL - 9 IS - 37 SP - 12591 EP - 12601 AN - OPUS4-53541 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Souza, B. A1 - Chauque, S. A1 - de Oliveira, P. A1 - Emmerling, Franziska A1 - Torresi, R. T1 - Mechanochemical optimization of ZIF-8/Carbon/S8 composites for lithium-sulfur batteries positive electrodes JF - Journal of Electroanalytical Chemistry N2 - The application of lithium-sulfur (Li-S) batteries is still limited by their rapid capacity fading. The pulverization of the sulfur positive electrode after the lithiation and the consequence dissolution of long chain polysulfides in organic solvents lead to the shuttle effect. To address these issues, here we report the mechanochemical preparation of ZIF-8 (Zeolitic Imidazole Framework-8)-based composites as sulfur hosts for positive electrodes in Li-S batteries. We studied different methods for the incorporation of conductive carbon. Also, the replacement of Zn2+ metal centers by other bivalent metals (Cu2+, Co2+ and Ni2+), enabled the preparation of other ZIF-8-based materials. The positive electrode ZIF-8/C/S8 showed initial discharges of 772 mA h g−1 while the pristine one, ZIF-8/S8, displayed 502 mA h g−1. The enhanced performance of 54% for ZIF-8/C/S8 indicates that the direct mechanochemical synthesis of ZIF-8 with conductive carbon is beneficial at initials charge/discharge process in comparison to traditional slurry preparation (ZIF-8/S8). Also, the Li2S6 absorption tests shows 87% of discoloration with ZIF-8/C/S8, confirming the better polysulfides absorption. KW - Lithium-sulfur battery KW - Metal organic frameworks KW - ZIF-8 KW - Mechanochemistry PY - 2021 DO - https://doi.org/10.1016/j.jelechem.2021.115459 VL - 896 SP - 115459 PB - Elsevier B.V. AN - OPUS4-53542 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Feiler, Torvid A1 - Bhattacharya, Biswajit A1 - Michalchuk, Adam A1 - Rhim, S.-Y. A1 - Schöder, V. A1 - List-Kratochvil, E. A1 - Emmerling, Franziska T1 - Tuning the mechanical flexibility of organic molecular crystals by polymorphism for flexible optical waveguides JF - CrystEngComm N2 - The ability to selectively tune the optical and the mechanical properties of organic molecular crystals offers a promising approach towards developing flexible optical devices. These functional properties are sensitive to crystallographic packing features and are hence expected to vary with polymorphic modification. Using as a model system the photoluminescent material 4-bromo-6-[(6-chloropyridin-2-ylimino)methyl]phenol (CPMBP), we herein demonstrate the simultaneous tuning of mechanical flexibility and photoluminescence properties via polymorphism. Two new polymorphic forms of CPMBP were obtained from a solution and fully characterised using a combination of experiments and density functional theory simulations. These polymorphic forms exhibit remarkably distinct mechanical properties and an order of magnitude difference in photoluminescence quantum yield. The mechanically plastic form has a higher quantum yield than the brittle polymorphic form. However, their photoluminescence emission profile is largely unaffected by the observed polymorphism, thereby demonstrating that the optical properties and bulk mechanical properties can in principle be tuned independently. By distinguishing between active (involving absorption and emission) and passive (involving no absorption) light propagation, the waveguiding properties of the plastic form of CPMBP (form II) were explored using the straight and bent crystals to highlight the potential applications of CPMBP in designing flexible optical devices. Our results demonstrated that polymorph engineering would be a promising avenue to achieve concurrent modulation of the optical and mechanical properties of photoluminescent molecular crystals for next-generation flexible optical device applications. KW - Mechanochemistry KW - Flexible PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-532075 DO - https://doi.org/10.1039/d1ce00642h VL - 23 IS - 34 SP - 5815 EP - 5825 PB - Royal Society of Chemistry CY - London AN - OPUS4-53207 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Linberg, Kevin A1 - Michalchuk, Adam A1 - Emmerling, Franziska T1 - Tipping the Energy Scales to Control Mechanochemical Polymorphism N2 - Control of ball milling conversions is required before the full potential of mechanochemical processing can be realized. It is well known that many parameters affect the outcome of mechanochemical polymorphism, but the energy of ball milling itself is often overlooked. We show here how this parameter alone can exert a significant influence on the polymorphic outcome of ball mill grinding by allowing the selective isolation of two polymorphic forms in their pure form under the same grinding conditions. Furthermore, we show how apparent mechanochemical equilibria can be deceptive. Our results clearly demonstrate the need for careful design and interpretation of ball milling experiments beyond current thinking. T2 - SALSA make and measure CY - Online meeting DA - 16.09.2021 KW - Mechanochemistry KW - Energy KW - Polymorph KW - Cocrystal PY - 2021 AN - OPUS4-53293 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Linberg, Kevin A1 - Michalchuk, Adam A1 - Emmerling, Franziska A1 - Gaydamaka, A. A1 - Belenguer, A. A1 - Giordano, N. A1 - Zakharov, B. A1 - Boldyreva, E. T1 - Insights into Mechanochemical Reactions using High Pressure XRD and DFT Simulations N2 - The reactivity of organic solids under mechanochemical conditions remains very little understood, though many processes have been found empirically. Importantly, it is not well understood how mechanical treatment induces experimentally observed chemical transformations, and if the elevated pressures arising at the point of impact can play a role in the transformation. To understand this aspect of the mechanochemical reactions, the same compounds need to be explored under high pressure conditions. As a model system, we considered the reaction between the bis(4-chlorophenyl) disulfide and bis(2-nitrophenyl) disulfide. A powder mixture of these two compounds is known to undergo a disulfide exchange reaction under ball milling conditions. Using a combination of X-ray powder diffraction and dispersion-corrected density functional theory calculations, we investigated how this binary solid system behaves at elevated pressures and whether pressure alone can explain its mechanochemical reactivity. T2 - International Scientific Student Conference 2021 CY - Online meeting DA - 12.04.2021 KW - Mechanochemistry KW - High Pressure KW - Density-functional theory PY - 2021 AN - OPUS4-52494 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Michalchuk, Adam A1 - Boldyreva, E. A1 - Belenguer, A. M. A1 - Emmerling, Franziska A1 - Boldyrev, V. V. T1 - Tribochemistry, mechanical alloying, mechanochemistry: what is in a name? JF - Frontiers in chemistry N2 - Over the decades, the application of mechanical force to influence chemical reactions has been called by various names: mechanochemistry, tribochemistry, mechanical alloying, to name but a few. The evolution of these terms has largely mirrored the understanding of the field. But what is meant by these terms, why have they evolved, and does it really matter how a process is called? Which parameters should be defined to describe unambiguously the experimental conditions such that others can reproduce the results, or to allow a meaningful comparison between processes explored under different conditions? Can the information on the process be encoded in a clear, concise, and self-explanatory way? We address these questions in this Opinion contribution, which we hope will spark timely and constructive discussion across the international mechanochemistry community. KW - Mechanochemistry KW - Tribochemistry KW - Mechanical alloying KW - Tribology KW - Mechanical activation KW - Nomenclature KW - Mechanochemical pictographs PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-523291 DO - https://doi.org/10.3389/fchem.2021.685789 SN - 2296-2646 VL - 9 SP - 1 EP - 29 PB - Frontiers Media CY - Lausanne AN - OPUS4-52329 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -