TY - JOUR A1 - Müller, Ralf A1 - Behrens, Harald A1 - Ageo-Blanco, Boris A1 - Reinsch, Stefan A1 - Wirth, Thomas T1 - Foaming Species and Trapping Mechanisms in Barium Silicate Glass Sealants N2 - Barium silicate glass powders 4 h milled in CO2 and Ar and sintered in air are studied with microscopy, total carbon analysis, differential thermal Analysis (DTA), vacuum hot extraction mass spectroscopy (VHE-MS), Fourier-transformed infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), and time-of-flight secondary-ion mass spectrometry (TOF-SIMS). Intensive foaming of powder compacts is evident, and VHE studies prove that foaming is predominantly caused by carbonaceous species for both milling gases. DTA Shows that the decomposition of BaCO3 particles mix-milled with glass powders occurs at similar temperatures as foaming of compacts. However, no carbonate at the glass surface could be detected by FTIR spectroscopy, XPS, and TOF-SIMS after heating to the temperature of sintering. Instead, CO2 molecules unable to rotate identified by FTIR spectroscopy after milling, probably trapped by mechanical dissolution into the glass bulk. Such a mechanism or microencapsulation in cracks and particle aggregates can explain the contribution of Ar to foaming after intense milling in Ar atmosphere. The amount of CO2 molecules and Ar, however, cannot fully explain the extent of foaming. Carbonates mechanically dissolved beneath the surface or encapsulated in cracks and micropores of particle aggregates are therefore probably the major foaming source. KW - Milling KW - Foaming KW - Glass powder KW - Sintering PY - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-531227 SN - 1438-1656 VL - 24 IS - 6 SP - 2100445-1 EP - 2100445-13 AN - OPUS4-53122 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Fischer, Franziska A1 - Heidrich, Adrian A1 - Greiser, Sebastian A1 - Rademann, K. A1 - Emmerling, Franziska T1 - Polymorphism of mechanochemically synthesized Cocrystals: an in situ study N2 - In situ investigations using PXRD coupled with Raman spectroscopy permit the evaluation of the formation pathways of milling reactions. The liquid-assisted grinding cocrystallisation of theophylline with benzamide leading to polymorphic compounds was investigated. The dipole moment of the solvent used in the synthesis determines the structure of the polymorphic product. A detailed investigation allows determining the kinetically and thermodynamically favored product. In situ observations of the formation pathway during the grinding process of both polymorphs show that the thermodynamically favored cocrystal is formed in a two-step mechanism with the kinetic cocrystal as intermediate. The evaluation of the mechanochemical formation pathways reveals the importance of in situ investigations for an in depth understanding of mechanochemical synthesis mechanisms. Our study demonstrates that the choice of the solvent in the LAG synthesis is decisive for the controlled formation of a desired polymorphic final product. T2 - CGOM/ BACG 47th Annual British Association of Crystal Growth Conference CY - Leeds, UK DA - 28.06.2016 KW - Cocrystal KW - Mechanochemistry KW - Milling PY - 2016 AN - OPUS4-36764 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Fischer, Franziska A1 - Lubjuhn, Dominik A1 - Greiser, Sebastian A1 - Rademann, K. A1 - Emmerling, Franziska T1 - Supply and demand in the ball mill: competitive cocrystal reactions N2 - The stability of different theophylline cocrystals under milling conditions was investigated by competitive cocrystal reactions. To determine the most stable cocrystal form under milling conditions, the active pharmaceutical ingredient theophylline was either ground with two similar coformers (benzoic acid, benzamide, or isonicotinamide), or the existing theophylline cocrystals were ground together with a competitive coformer. All competitive reactions were investigated by in situ powder X-ray diffraction disclosing the formation pathway of the milling processes. On the basis of these milling reactions, a stability order (least to most stable) was derived: tp/bs < tp/ba < tp/ina < bs/ina. KW - Mechanochemistry KW - Cocrystal KW - Milling PY - 2016 U6 - https://doi.org/10.1021/acs.cgd.6b00928 SN - 1528-7483 SN - 1528-7505 VL - 16 IS - 10 SP - 5843 EP - 5851 AN - OPUS4-38097 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Fischer, Franziska A1 - Kulla, Hannes A1 - Emmerling, Franziska A1 - Rademann, K. T1 - In situ investigation of the mechanochemical formation of cocrystals unsing combined PXRD and Raman spectroscopy N2 - We present an in situ investigation of the mechanochemical formation of cocrystals using synchrotron XRD and Raman spectroscopy. This combination allows to study milling processes on the level of the molecular and crystalline structure thus obtaining reliable data for mechanistic studies. Thereby, mechanochemical syntheses can be optimized to isolate new crystal structures. T2 - Joint BER II and BESSY II User Meeting 2016 CY - Berlin, Germany DA - 07.12.2016 KW - Intermediate KW - Mechanochemistry KW - Cocrystal KW - In situ KW - Milling PY - 2016 AN - OPUS4-38722 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Breitfeld, Steffen A1 - Scholz, G. A1 - Emmerling, Franziska A1 - Kemnitz, E. T1 - BaF-benzenedicarboxylate: the first mechanochemical N2 - Anewbariumcoordination polymer, BaF-benzenedicarboxylate (BaF(p-BDC)0.5), with fluorine directly coordinated to the metal cation, was prepared by mechanochemical synthesis routes. Phase-pure BaF-benzenedicarboxylate was synthesized by milling starting either from barium hydroxide or from Barium acetate as sources for barium cations. In both cases, the second reactant was 1,4-benzenedicarboxylic acid (H2(p-BDC)). Ammonium fluoride was used as fluorinating agent directly at milling. This is the first mechanochemical synthesis of coordination polymers where fluorine is directly coordinated to the metal cation. Following the second possibility, barium acetate fluoride (Ba(OAc)F) is formed as ntermediate product after milling, and the new coordination polymer is accessible only after washing with water and dimethyl sulfoxide. The new compound BaF(p-BDC)0.5 was characterized by X-ray powder diffraction, FTIR-, and 19F, 1H-13C CP MAS NMR spectroscopies, DTA-TG, and elemental Analysis. KW - Milling KW - MOF PY - 2018 U6 - https://doi.org/10.1007/s10853-018-2331-3 SN - 0022-2461 VL - 53 IS - 19 SP - 13682 EP - 13689 PB - Springer AN - OPUS4-45677 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kulla, Hannes A1 - Becker, C. A1 - Casati, N. A1 - Paulus, B. A1 - Rademann, K. A1 - Emmerling, Franziska T1 - In situ investigations of a mechanochemical cocrystal formation by X-ray diffraction for two different milling jar materials N2 - Mechanochemistry has become a valuable method for the synthesis of new materials, especially for pharmaceutical cocrystals. The Advantages of fast reactions in high purity and yield face a lack of understanding the underlying mechanism. Therefore, in situ setups to study mechanochemical reactions have been established. Herein, we present an in situ investigation of the mechanochemical cocrystal formation of pyrazinamide (PZA) with pimelic acid (PM) using synchrotron XRD. Two new polymorphs of PZA:PM (1:1) were synthesized by milling the starting materials in milling jars of different materials. While Form I is only obtained using a steel jar, Form II can be obtained purely in jars made of Perspex. In situ XRD experiments reveal a direct formation of Form II in Perspex and an intermediate formation of Form II in steel jars converting to Form I upon further grinding. Heating experiments and DFT calculations predict that Form II is the thermodynamically more stable polymorph. Therefore, the reaction progress in the steel jar contradicts Ostwald’s rules of stages as the more stable Form II converts into the metastable Form I. Hence, mechanochemistry offers the possibility to synthesize new materials that cannot be obtained using conventional methods. T2 - Adlershofer Forschungsforum 2017 CY - HU-Berlin, Erwin-Schrödinger Zentrum, Germany DA - 10.11.2017 KW - Cocrystal KW - Mechanochemistry KW - Polymorph KW - In situ KW - Milling PY - 2017 AN - OPUS4-42956 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kulla, Hannes A1 - Becker, Christian A1 - Casati, Nicola A1 - Paulus, Beate A1 - Rademann, Klaus A1 - Emmerling, Franziska T1 - In situ PXRD monitoring of a mechanochemical cocrystal formation in milling jars of different material N2 - We present an in situ PXRD investigation of the mechanochemical cocrystal formation of pyrazinamide with pimelic acid in two milling jar materials. In the steel jar a polymorph transformation presenting an exception of Ostwald’s rule of stages is observed. T2 - BESSY User Meeting 2017 CY - Bessy II (HZB), Berlin, Germany DA - 14.12.2017 KW - In situ KW - XRD KW - Polymorph KW - Cocrystal KW - Milling PY - 2017 AN - OPUS4-43502 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kulla, Hannes A1 - Wilke, Manuel A1 - Fischer, Franziska A1 - Röllig, Mathias A1 - Maierhofer, Christiane A1 - Emmerling, Franziska T1 - Warming up for mechanosynthesis – temperature development in ball mills during synthesis N2 - We present a first direct measurement of the temperature during milling combined with in situ Raman spectroscopy monitoring. The data reveal a low temperature increase due to the mechanical impact and clear temperature increases as a consequence of the reaction heat. Based on the data, temperature rises as postulated in the magma plasma and hot spot theory can be excluded for soft matter milling syntheses. KW - Thermography KW - Milling KW - Mechanochemistry KW - Soft matter PY - 2017 U6 - https://doi.org/10.1039/c6cc08950j SN - 1364-548X SN - 1359-7345 SN - 0009-241X VL - 53 IS - 10 SP - 1664 EP - 1667 AN - OPUS4-39251 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Agea Blanco, Boris A1 - Reinsch, Stefan A1 - Müller, Ralf T1 - Sintering and Foaming of Barium Silicate Glass Powders N2 - The manufacture of sintered glasses and glass-ceramics, glass matrix composites, and glass-bounded ceramics or pastes is often affected by gas bubble formation. Against this background, we studied sintering and foaming of barium silicate glass powders used as SOFC sealants using different powder milling procedures. Sintering was measured by means of heating microscopy backed up by XPD, differential thermal analysis, vacuum hot extraction (VHE), and optical and electron microscopy. Foaming increased significantly as milling progressed. For moderately milled glass powders, subsequent storage in air could also promote foaming. Although the powder compacts were uniaxially pressed and sintered in air, the milling atmosphere significantly affected foaming. The strength of this effect increased in the order Ar ≈ N2 < air < CO2. Conformingly, VHE studies revealed that the pores of foamed samples predominantly encapsulated CO2, even for powders milled in Ar and N2. Results of this study thus indicate that foaming is caused by carbonaceous species trapped on the glass powder surface. Foaming could be substantially reduced by milling in water and 10 wt% HCl. T2 - 91. Glastechnische Tagung CY - Weimar, Germany DA - 29.05.2017 KW - Glass powder sintering KW - Milling KW - Foaming KW - Degassing KW - SOFC PY - 2017 AN - OPUS4-42858 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Haferkamp, Sebastian A1 - Emmerling, Franziska A1 - Akhmetova, Irina A1 - Kulla, Hannes A1 - Rademann, K. T1 - In situ investigations of mechanochemical reactions N2 - Mechanochemistry paves the way to simple, fast, and green syntheses. Despite considerable effort, there remains a lack in understanding of the underlying mechanisms. In situ investigations help to understand these mechanisms, which occur during a mechanochemical reaction. Here we present a universal strategy for simultaneous real-time in situ analysis, combining X-ray diffraction, Raman spectroscopy, and thermography. The potential of our approach is shown for different model reactions. T2 - ANAKON 2019 CY - Münster, Germany DA - 25.03.2019 KW - In situ KW - Mechanochemistry KW - Milling PY - 2019 AN - OPUS4-47701 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Altmann, Korinna A1 - Waniek, Tassilo T1 - Needs, concepts and state of the art: Top-down production of reference materials for micro- and nanoplastics and their use in harmonisation processes N2 - The talk explains the top-down production of materials suitable for mircoplastics and nanoplastics and the use in ILCs. T2 - EUROLAB webinar: MICROPLASTICS: regulations, standards and the role of laboratories CY - Online meeting DA - 15.02.2023 KW - Microplastics KW - Nanoplastics KW - ILC KW - Milling PY - 2023 AN - OPUS4-57008 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -