Surface and Bulk Modifications of Fibrous Erionite in Mimicked Gamble’s Solution at Acidic pH

Minerals

Maria Rita Montereali¹  Raffaela Caprioli¹  Lorenzo Arrizza²  Marzia Fantauzzi³  Antonella Rossi³  Cecilia Viti⁴  Alessandro Pacella⁵  Paolo Ballirano⁵  Elisa Nardi⁶ 

[1] Agenzia Nazionale per le Nuove Tecnologie, l’energia e lo Sviluppo Economico Sostenibile (ENEA), S. Maria di Galeria, I-00123 Rome, Italy;Centro di Microscopie, Università degli Studi dell’Aquila, I-67100 L’Aquila, Italy;Dipartimento di Scienze Chimiche e Geologiche, INSTM Research Unit, Università di Cagliari, I-09042 Monserrato, Italy;Dipartimento di Scienze Fisiche, della Terra e dell’Ambiente, Università di Siena, I-53100 Siena, Italy;Dipartimento di Scienze della Terra and Laboratorio Rettorale Fibre e Particolato Inorganico, Sapienza Università di Roma, I-00185 Rome, Italy;Istituto Superiore per la Protezione e la Ricerca Ambientale (ISPRA), I-00144 Roma, Italy;

关键词: fibrous erionite;    fibre dissolution;    cation exchange;    Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES);    X-ray Photoelectron Spectroscopy (XPS);    Transmission Electron Microscopy (TEM);   

DOI  :  10.3390/min11090914

来源: DOAJ

【 摘 要 】

This study aimed at investigating both the surface and bulk modifications occurring on fibrous erionite during leaching in a mimicked Gamble’s solution (MGS) at pH of 4.5 and T = 37 °C, up to one month of incubation. Samples were characterized by a multi-analytical approach: field-emission scanning electron microscopy (FE-SEM) was employed to investigate the morphological changes of both pristine and reacted fibres, inductively coupled plasma optical emission spectrometry (ICP-OES) was used to measure the concentration of the released cations; X-ray photoelectron spectroscopy (XPS) was exploited for highlighting possible modifications of surface chemistry; X-ray powder diffraction (XRPD) and high-resolution transmission electron microscopy (HR-TEM) were applied aiming to get information on the structural state of the fibres following the incubation. ICP results integrated with those obtained by both bulk- and surface-chemical characterization highlighted that erionite binds Na especially in the first 24 h of sample incubation in the MGS, following ion exchange with the extra framework cations, in particular Ca. Moreover, our new results show that the Na binding process caused structural modifications with the migration of Na toward the Ca2 site and redistribution of the cations within the erionite cage. TEM investigation pointed out that the interaction between erionite and MGS results in the formation of a new surface amorphous layer with an irregular lobate pattern on an earlier surface weathered layer. However, the silicate framework is not weakened by incubation in the MGS at acidic pH. In addition, on the basis of the Si release normalized to the mineral surface area, fibrous erionite resulted significantly more biodurable than amphibole asbestos. Notably, considering the primary role played by biodurability in inducing pathogenicity, this result certainly supports in vivo observations showing that erionite is much more tumorigenic than asbestos. Moreover, the ions released by erionite when immersed in MGS may trigger biological effects, such as those on lipid packing and membrane permeability. On this basis, we expect a regulatory definition that would provide protection from this carcinogenic fibre.

【 授权许可】

Unknown