Coupling SEM-EDS and confocal Raman-in-SEM imaging: A new method for identification and 3D morphology of asbestos-like fibers in a mineral matrix

Abstract

Asbestos consists in natural minerals crystallized in a specific habit and possessing in particular properties. In the case of Naturally Occurring Asbestos, usual methods applied to the identification of mineral fibers and the determination of their possible asbestiform nature seems not efficient, especially in the case of mineral fibers included in mineral matrix.We present a new in-situ method based on the use of confocal Raman-in-SEM imaging implemented in a Scanning Electron Microscope as an efficient method for in-situ mineralogy. The limitation of conventional methods is discussed. We applied 2D-Raman imaging to the identification of sub-micrometric fibers included in different mineral matrix. We were able to identify actinolite fibers down to 400 nm in diameter, included in feldspar, quartz and/or calcite matrix. HighlightsNew methods are requested for characterizing asbestos fibers in a mineral matrix SEM-Raman imaging is efficient for characterizing mineral fibers in-situ Confocal Raman imaging makes 3D analysis possible 3D analysis provides information on the aspect ratio and volume fraction of asbestos Fibers thinner than 400nm can be identified by confocal Raman in SEM ( = 532 nm) Keywords in-situ asbestos diagnosis; Raman-in-SEM imaging; naturally occurring asbestos; 3D analysis; fibrous amphiboles;

Controlling Particle Size and Phase Purity of “Single-Crystal” LiNi0.5Mn1.5O4 in Molten-Salt-Assisted Synthesis

“…We suggest that correlative scanning electron microscopy and Raman spectroscopy (SEM-Raman), a powerful combination providing high-resolution morphological, structural, and chemical information can meet the challenge. This technique has been applied to study two-dimensional materials and minerals . However, to the best of our knowledge, it has not been applied to study LNMO (or any battery materials) and its preparation process.…”

“…This technique has been applied to study twodimensional materials 31 and minerals. 32 However, to the best of our knowledge, it has not been applied to study LNMO (or any battery materials) and its preparation process.…”

Linking the physical and chemical characteristics of single small microplastics or nanoplastics via photolithographic silicon substrates

“…20 Otherwise, it could only be done using a dedicated SEM–Raman microscope which may not be readily available. 21–23…”

“…20 Otherwise, it could only be done using a dedicated SEM-Raman microscope which may not be readily available. [21][22][23] 3.2 Characterization of tiny particles via SEM and AFM Scanning probe microscopes are not intended for characterization of single particles under most circumstances while our designs proved effective in practice. We rstly recorded the positional information of individual particles under the SEM (Fig.…”

Stokes Flow Induced Drag and Torque on Asbestos-Like Fibres Cannot Be Estimated by a Simplistic Ellipsoidal Approximation

“…Many researchers [2]- [4] model asbestos fibres as elongated ellipsoids. In reality [5]- [8], however, the shape of the particle can be curved, rod-shaped and contain protrusions, so the simplifying ellipsoid approximation can be questionable. In this paper, we compare the drag and torque exerted on a fibre using a 3D model of a realistic asbestos-like mineral and its simplifying ellipsoidal approximation by means of BEM-based numerical simulation.…”