Kahlenberg Volker, Braun Doris E, Schmidt Wolfgang, Liu Hang, Leiting Sebastian, Weidenthaler Claudia
University of Innsbruck, Institute of Mineralogy and Petrography Innrain 52 A-6020 Innsbruck Austria.
University of Innsbruck, Institute of Pharmacy, Pharmaceutical Technology Innrain 52c A-6020 Innsbruck Austria.
RSC Mechanochem. 2024 Nov 28;2(1):152-158. doi: 10.1039/d4mr00093e. eCollection 2025 Jan 14.
This study presents the mechanochemical synthesis of the two KCa(CO) polymorphs, fairchildite and buetschliite, from CaCO and KCO using a shaker mill. Unlike previous methods requiring high temperatures and prolonged heating, fairchildite, a high-temperature polymorph, is formed initially in all experiments, adhering to Ostwald's rule of stages. Notably, the transformation to the stable buetschliite phase can be achieved by varying milling parameters, particularly frequency and moisture content. The results suggest that pressure, rather than temperature, plays a significant role in this phase transition, with moisture further accelerating the transformation. These findings offer a new, efficient route for the synthesis of these polymorphs, highlighting the critical influence of milling conditions on the reaction pathway.
本研究介绍了使用振动磨由碳酸钙和碳酸钾通过机械化学合成两种KCa(CO)多晶型物，即钙镁石和贝氏石。与以往需要高温和长时间加热的方法不同，在所有实验中最初都会形成高温多晶型物钙镁石，这符合奥斯特瓦尔德阶段规则。值得注意的是，通过改变研磨参数，特别是频率和水分含量，可以实现向稳定的贝氏石相的转变。结果表明，压力而非温度在这一相变中起重要作用，水分会进一步加速转变。这些发现为合成这些多晶型物提供了一条新的、高效的途径，突出了研磨条件对反应途径的关键影响。
