TY - JOUR A1 - Linberg, Kevin A1 - Emmerling, Franziska A1 - Michalchuk, Adam T1 - Unintended Rate Enhancement in Mechanochemical Kinetics by Using Poly(methyl methacrylate) Jars JF - Crystal Growth & Design N2 - Time-resolved in situ (TRIS) X-ray diffraction has changed how mechanochemical transformations are studied but requires the use of X-ray transparent jars often made from poly(methyl methacrylate) (PMMA). However, using PMMA jars can alter the apparent kinetics of mechanochemical polymorphism by an order of magnitude, questioning the interpretability of established TRIS methods. Our results suggest that rate enhancement in PMMA jars may not be dominated by chemical effects of the polymer, but rather a result of different equilibrium temperatures within the jar. These features must be better understood before control over mechanochemical reactions can be achieved. KW - Mechanochemistry KW - Organic compounds KW - Polymers KW - Materials PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-565276 DO - https://doi.org/10.1021/acs.cgd.2c01227 SN - 1528-7483 SP - 1 EP - 5 PB - ACS Publications AN - OPUS4-56527 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Smales, Glen Jacob T1 - Structural characterization using small-angle X-ray scattering (SAXS) N2 - A short introduction to small-angle scattering, followed by a "choose your own adventure" style of talk on the characterisation of different materials using SAXS/WAXS. T2 - Operando workshop “SAXS and Ptychography” at the Paul Scherrer Institut CY - Villigen, Switzerland DA - 17.08.2021 KW - SAXS KW - Materials KW - Characterisation PY - 2021 AN - OPUS4-53188 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ghazanfari, M. R. A1 - Vittadello, L. A1 - Al-Sabbagh, Dominik A1 - Santhosh, A. A1 - Frankcom, C. A1 - Fuß, F. A1 - von Randow, C. A. A1 - Siemensmeyer, K. A1 - Vrijmoed, J. C. A1 - Emmerling, Franziska A1 - Jerabek, P. A1 - Irmlau, M. A1 - Thiele, G. T1 - Remarkable Infrared Nonlinear Optical, Dielectric, and Strong Diamagnetic Characteristics of Semiconducting K3[BiS3] JF - The journal of physical chemistry letters N2 - The ternary sulfido bismuthate K3[BiS3] is synthesized in quantitative yields. The material exhibits nonlinear optical properties with strong second harmonic generation properties at arbitrary wavelengths in the infrared spectral range and a notable laser-induced damage threshold of 5.22 GW cm−2 for pulsed laser radiation at a wavelength of 1040 nm, a pulse duration of 180 fs, and a repetition rate of 12.5 kHz. K3[BiS3] indicates semiconductivity with a direct optical band gap of 2.51 eV. Dielectric and impedance characterizations demonstrate κ values in the range of 6−13 at 1 kHz and a high electrical resistivity. A strong diamagnetic behavior with a susceptibility of −2.73 × 10−4 m3 kg−1 at room temperature is observed. These results suggest it is a promising nonlinear optical candidate for the infrared region. The synergic physical characteristics of K3[BiS3] provide insight into the correlation of optical, electrical, and magnetic properties. KW - Electrical properties KW - Insulators KW - Materials KW - Nonlinear optics KW - Quantum mechanics PY - 2022 DO - https://doi.org/10.1021/acs.jpclett.2c01689 VL - 13 IS - 30 SP - 6987 EP - 6993 PB - ACS Publications AN - OPUS4-55456 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kulla, Hannes A1 - Becker, C. A1 - Michalchuk, Adam A1 - Linberg, Kevin A1 - Paulus, B. A1 - Emmerling, Franziska T1 - Tuning the Apparent Stability of Polymorphic Cocrystals through Mechanochemistry JF - Crystal Growth & Design N2 - Mechanochemistry has become a valuable method for the synthesis of new materials and molecules, with a particular strength for screening and preparing multicomponent crystals. In this work, two novel cocrystals of pyrazinamide (PZA) with pimelic acid (PA) were prepared mechanochemically. Their formation was monitored in real time by in situ synchrotron powder X-ray diffraction. Control over the polymorphic form was obtained through the selective choice of liquid additive via liquid assisted grinding. Slurry experiments and dispersion-corrected density functional theory calculations suggest that Form I is the thermodynamically stable form under ambient conditions. Upon aging, Form II converts to Form I. The stability of Form II upon aging was found to depend strongly on the milling duration, intensity, and material of the milling vessels. Longer or higher energy milling drastically increased the lifetime of the Form II product. For the first time, this work also demonstrates that the choice of milling jar can have a decisive effect on the aging stability of a bulk polymorphic powder. In contrast to material prepared in steel milling vessels, the preparation of Form II in Perspex (PMMA) vessels increased its lifetime 3-fold. These findings offer a new dimension to garnering control over mechanochemical cocrystallization and demonstrate the critical importance of the careful and timely ex situ screening of ball mill grinding reactions. This will be of importance for potential industrial applications of mechanochemical cocrystallization where understanding polymorph longevity is crucial for the development of a robust preparative protocol. KW - Physical and chemical processes KW - Organic compounds KW - Liquids KW - Materials KW - Stability PY - 2019 DO - https://doi.org/10.1021/acs.cgd.9b01158 VL - 19 IS - 12 SP - 7271 EP - 7279 PB - ACS Publications AN - OPUS4-50281 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -