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DOI	10.5194/acp-21-11801-2021
	Effect of chemically induced fracturing on the ice nucleation activity of alkali feldspar
	Kiselev A.A.; Keinert A.; Gaedeke T.; Leisner T.; Sutter C.; Petrishcheva E.; Abart R.
发表日期	2021
ISSN	1680-7316
起始页码	11801
结束页码	11814
卷号	21 期号:15
英文摘要	Feldspar is an important constituent of airborne mineral dust. Some alkali feldspars exhibit particularly high ice nucleation (IN) activity. This has been related to structural similarities of the ice (1013/40) prism planes and the (100) planes of alkali feldspar. Here the effect of generating feldspar surfaces with close to (100) orientation by means of chemically induced fracturing on the IN activity of alkali feldspar was investigated experimentally. To this end, gem-quality K-rich alkali feldspar was shifted towards more Na-rich compositions by cation exchange with an NaCl-KCl salt melt at 850 C. By this procedure, a system of parallel cracks with an orientation close to the (100) plane of the feldspar was induced. Droplet-freezing assay experiments performed on grain mounts of the cation-exchanged alkali feldspars revealed an increase in the overall density of ice-nucleating active site (INAS) density with respect to the untreated feldspar. In addition, annealing at 550 C subsequent to primary cation exchange further enhanced the INAS density and led to IN activity at exceptionally high temperatures. Although very efficient in experiment, fracturing by cation exchange with an alkali halide salt is unlikely to be of relevance in the conditioning of alkali feldspars in nature. However, parting planes with similar orientation as the chemically induced cracks may be generated in lamellar microstructures resulting from the exsolution of initially homogeneous alkali feldspar, a widespread phenomenon in natural alkali feldspar known as perthite formation. Perthitic alkali feldspars indeed show the highest IN activity. We tentatively ascribe this phenomenon to the preferential exposure of feldspar crystal surfaces oriented sub-parallel to (100). © Copyright:
语种	英语
scopus关键词	alkali feldspar; cloud droplet; ice crystal; mineral dust; nucleation
来源期刊	ATMOSPHERIC CHEMISTRY AND PHYSICS
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/246674
作者单位	Karlsruhe Institute of Technology, Institute of Meteorology and Climate Research, Karlsruhe, Germany; Institut für Umweltphysik, Universität Heidelberg, Heidelberg, Germany; Department of Lithospheric Research, University of Vienna, Althanstrasse 14, Vienna, 1090, Austria
推荐引用方式 GB/T 7714	Kiselev A.A.,Keinert A.,Gaedeke T.,et al. Effect of chemically induced fracturing on the ice nucleation activity of alkali feldspar[J],2021,21(15).
APA	Kiselev A.A..,Keinert A..,Gaedeke T..,Leisner T..,Sutter C..,...&Abart R..(2021).Effect of chemically induced fracturing on the ice nucleation activity of alkali feldspar.ATMOSPHERIC CHEMISTRY AND PHYSICS,21(15).
MLA	Kiselev A.A.,et al."Effect of chemically induced fracturing on the ice nucleation activity of alkali feldspar".ATMOSPHERIC CHEMISTRY AND PHYSICS 21.15(2021).