Optimization for the Preparation of Sepiolite Nanofibers via a Combination of Physical and Chemical Purifications

In recent years, the continuous advancement of nanotechnology has promoted the wide application of natural mineral materials in various fields. Due to its unique mineralization conditions, natural sepiolite usually exists in nature in the form of fiber bundles, and the internal pores of sepiolite fibers are often clogged and the presence of a large number of impurities limits its surface modification and its application. Therefore, in order to further enhance the application potential of sepiolite as a natural mineral, it is necessary to pretreat, purify and depolymerize sepiolite to obtain sepiolite nanofibers. In this paper, a technique combining two methods, gravity sedimentation (physical method) and acid purification (chemical method), was used to prepare sepiolite nanofibers. This technique is not only low-pollution, low-energy consumption and easy to operate, but also the produced sepiolite nanofibers have better dispersibility, adsorption and its specific surface area has been significantly improved from 1.969[Formula: see text]m 2 /g to 79.219[Formula: see text]m 2 /g, which is about 40 times. The pore volume was enhanced from 0.009[Formula: see text]cm 3 /g to 0.153[Formula: see text]cm 3 /g. The average pore size was reduced from 35.517[Formula: see text]nm to 9.753[Formula: see text]nm.