Effects of grinding montmorillonite and illite on their modification by dioctadecyl dimethyl ammonium chloride and adsorption of perchlorate: Fid-Bau Portal

Effects of grinding montmorillonite and illite on their modification by dioctadecyl dimethyl ammonium chloride and adsorption of perchlorate

Luo, Wuhui / Fukumori, Takeru / Guo, Binglin / Osseo-Asare, Kwadwo / Hirajima, Tsuyoshi / Sasaki, Keiko

Abstract

AbstractMontmorillonite (Mt) and illite (Ilt) were ground for different times under wet condition and sequentially subjected to organic modification by dioctadecyl dimethyl ammonium chloride (DDAC). The influence of the grinding time on the obtained products in terms of DDAC loading and ${ClO}_{4}^{-}$ adsorption were evaluated. Multiple techniques were used to characterize the changes in structure and morphology before and after mechanical or organic modification. Compared with Ilt, Mt showed a stronger resistance to mechanical treatment due to its swelling property. Silicon nuclear magnetic resonance (²⁹Si NMR) spectra and X-ray diffraction (XRD) patterns of samples ground for 30min indicate the disintegration of Ilt and exfoliation of Mt, resulting in increase of ${ClO}_{4}^{-}$ uptake by 147% for OIlt and 13% for OMt. Three stages in the grinding Mt can be proposed, including the separation of large particles into small particles, exfoliation of small particles, and disintegration of exfoliated single layers. In contrast, two stages are involved in the grinding Ilt, which are the destruction/exfoliation of large particles and further disintegration of small exfoliated layers.

Graphical abstract

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Highlights•Mt and Ilt were mechanically and organically modified for ${ClO}_{4}^{-}$ adsorption.•Wet grinding of Mt demonstrated a slight influence on ${ClO}_{4}^{-}$ adsorption.•Uptake of ${ClO}_{4}^{-}$ on OIlt was markedly affected by the grinding time of Ilt.•Grinding for 30min of Ilt led to an increase in uptake of ${ClO}_{4}^{-}$ by 147%.•Mt showed a higher resistance than Ilt to structural breakage by wet grinding.