Methyl orange (MO) is a common anionic azo dye that is harmful to the environment and biology, so it must be treated innocuously before it can be discharged. Adsorption is an effective method to remove anionic dyes. Nanotube mineral is a natural one-dimensional adsorption material, and its unique morphology and structure endow it with good adsorption capacity. Although there are many related studies, there is a lack of in-depth discussions on the influence of nanotube’s composition and structure on the adsorption of dyes and other pollutants. In this paper, two kinds of natural one-dimensional silicate minerals [halloysite nanotubes (HNTs) and chrysotile nanotubes (ChNTs)] with similar morphology but slightly different compositions and crystal structures were used as adsorbents, and MO solution was used as simulate pollutants. It is the first time to discuss in depth the influence of the composition and structure of nanotube minerals on their charge properties and the adsorption performance of methyl orange dyes. It is found that HNTs and ChNTs have different adsorption capacity due to the difference of electronegativity between Al3+ and Mg2+ in the crystal, so they possess negative and positive charges respectively in near-neutral solution, which leads to the adsorption capacity of MO by ChNTs with positive charges which is greater than that of HNTs.

Nano-CL-20/TNT cocrystal explosive was successfully prepared by mechanical ball milling with 0.38 mm grinding beads. The micromorphology and particle size of cocrystal explosive were characterized by scanning electron microscopy. The average particle size of nano-CL-20/TNT cocrystal explosive was 119.5 nm and showed a spherical-like micromorphology. The crystal structure of cocrystal explosive was characterized by powder X-ray diffraction, infrared spectroscopy, and Raman spectroscopy. The results show that mechanical ball milling does not change the molecular structure of the raw material, but the sample after ball milling has a new crystal phase, rather than a simple mixing of raw materials. Differential scanning calorimetry tests show that nano-CL-20/TNT cocrystal explosive has a higher decomposition temperature; impact sensitivity tests show that the properties of cocrystal explosive are 26 and 21.7 cm higher than those of CL-20 and CL-20/TNT mixture, respectively, which indicates that nano-CL-20/TNT cocrystal explosive has better thermal stability and safety.

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Aimed at improving vermiculite's thermal expansibility, a novel method of Na+ modification has been proposed. The influencing mechanism of Na+ modification on the thermal expansibility of vermiculite was explored.