Role of Impurities in Kaolinite Intercalation and Subsequent Formation of Nanoscrolls

Shilong Zhang; Qinfu Liu; Juanjuan Luo; Na Yang; Yi Zhang; Yang Liu; Luyi Sun

doi:10.1021/acs.inorgchem.3c01263

Role of Impurities in Kaolinite Intercalation and Subsequent Formation of Nanoscrolls

Inorg Chem. 2023 Aug 21;62(33):13205-13211. doi: 10.1021/acs.inorgchem.3c01263. Epub 2023 Jul 27.

Authors

Shilong Zhang^{1

2

3}, Qinfu Liu², Juanjuan Luo¹, Na Yang¹, Yi Zhang¹, Yang Liu⁴, Luyi Sun^{3

5}

Affiliations

¹ School of Physics and Electronics, Qiannan Normal University for Nationalities, Duyun 558000, China.
² School of Geological Science and Survey Engineering, China University of Mining and Technology, Beijing 100083, China.
³ Polymer Program, Institute of Materials Science, University of Connecticut, Storrs, Connecticut 06269, United States.
⁴ School of Public Health, Nantong University, Nantong 226019, China.
⁵ Department of Chemical and Biomolecular Engineering, University of Connecticut, Storrs, Connecticut 06269, United States.

PMID: 37497621
DOI: 10.1021/acs.inorgchem.3c01263

Abstract

Kaolinite (Kaol)-methanol (MeOH) compounds (Kaol-Me) are widely used as the starting materials for further intercalation. The conventional approach to prepare Kaol-Me compounds is to wash dimethyl sulfoxide (DMSO)-intercalated Kaol (Kaol-DMSO) for 16 days, and MeOH must be refreshed every day. Herein, we report a new and much more efficient method to prepare Kaol-Me from Kaol-DMSO by the promotion of AlCl₃ under mild conditions, and the corresponding mechanism is investigated. The X-ray diffraction (XRD), Fourier transform infrared spectroscopy, and X-ray fluorescence characterization results reveal that the electric double layer resulting from the impurities absorbed on the kaolinite surface prevents weakly polar molecules from entering the kaolinite interlayers, which is probably the key reason that MeOH must be refreshed daily in the preparation of Kaol-Me compounds. After being treated with HCl to remove the impurities, Kaol-Me-HCl was successfully intercalated by cetyltrimethyl ammonium bromide and subsequently predominantly curled into nanoscrolls.