Correlation of natural muscovite exfoliation with interlayer and solvation forces

Abstract

The correlation of natural muscovite exfoliation with interlayer and solvation forces was investigated in this work, respectively. The former was studied through exfoliating seven muscovite samples with different interlayer forces in 40% tert-butanol/water solvent, while the latter was performed by exfoliating a muscovite in various alcohol/water solvents. This study was implemented by means of measurements using a UV-VIS spectrophotometer, surface tension measurements, XRD, IR spectroscopy, and ICP-OES. The results indicated that the exfoliation degree of natural muscovite was strongly related to the interlayer and solvation forces. Weak interlayer forces facilitated the exfoliation of muscovite, which might be due to the fact that the interlayer structure was easily broken down. Solvents with a larger molecular size and similar surface energy to the muscovite (around 54.8 mJ m⁻²) were better for the exfoliation. This observation was attributed to the fact that the molecules of the solvents had stronger solvation forces to muscovite layers, leading them to intercalate into the adjacent layers to overcome the interlayer interactions and thus the exfoliation.