Synthesis and characterization of tremolite asbestos fibres

Fibres of Fe-free tremolitic amphibole were synthesized using hydrothermal conditions. The run products contained only minor amounts of one other phase, quartz, as determined by X-ray powder diffraction (XRPD). The fibrous material was characterized by scanning and transmission electron microscopies combined with energy dispersive spectrometry (SEM-EDS and TEM-EDS), differential scanning calorimetry (DSC), thermogravimetry (TG) and micro-Raman spectroscopy. The average length and width of the fibres, as determined by SEM and TEM on about 600 fibrils, fall within the definition of breathable fibres and potentially carcinogenic. Electron diffraction patterns of selected areas (SAED) from single fibres revealed a high crystallinity. Raman spectroscopy showed bands matching those observed on natural samples of tremolite. These synthetic and well-characterized fibres can be used in in vitro studies, where cell reactions to synthetic and natural tremolite fibres are compared.