The preparation of high-yield uniform nanotubes from coal-measure kaolinite

Abstract

A clean and efficient method was used to prepare kaolinite nanotubes from coal-measure kaolinite. Dimethyl sulfoxide, methanol, and cetyltrimethylammonium chloride were used to prepare intercalation compounds. We characterized the structures, surface functional group changes, morphology, and intercalation rates by x-ray diffraction (XRD), fourier transform infrared spectrometer (FT-IR), scanning electron microscopy (SEM), and transmission electron microscope (TEM). The intercalation rates of intercalation compounds of CK-D, CK-M, and CK-CTAC obtained from the x-ray diffraction (XRD) patterns reach 96.62%, 89.05%, and 86.96%, respectively. The morphology of the intercalation compounds of CK-D and CK-M did not change significantly before and after intercalation, showing a flaky accumulation similar to the original coal-measure kaolinite. Meanwhile, the macromolecular structure of the cetyltrimethylammonium chloride agent had a significant effect on the morphological changes of the kaolinite intercalation compounds. It can directly increase the basal spacing of coal-measure kaolinite from 7.15 Å to 38.38 Å, which is 5.36 times the original basal spacing. The energy input of the ultrasonic instrument can accelerate and enhance the exfoliation process of nanotube formation.