Abstract: A high-entropy austenitic stainless steel and a preparation method thereof are provided. The elemental composition of the stainless steels developed by the invention is as follows: Cr: 5-30%; Ni: 5-50%; Ti: 1-15%; Al: 1-15%; the rest are Fe and inevitable impurities; preferably, the composition is Cr: 5-19%; Ni: 5-29%; Ti: 6-15%; Al: 5-15%; the rest element is Fe. By adjusting the atomic ratio of each element, the nano-sized precipitates are generated as much as possible, and the strength is maximized while maintaining a high plasticity. The stainless steels provided by this invention have only five alloying components, a low manufacturing cost, and high-strength and high-plasticity. They can be widely used in many industrial fields such as aviation, aerospace, marine, and nuclear power with broad market prospects.

Abstract: Dispersible single-walled and multi-walled carbon nanotubes (CNTs) are prepared by dissolving surfactants in water to form a solution; adding carbon nanotubes to the solution to form a mixture; sonicating and agitating the mixture to form a carbon-nanotube/water dispersion; centrifuging the dispersion to remove un-dispersed carbon nanotubes and impurities; repeatedly freezing and heating the CNT dispersion; and, sublimating water in the CNT dispersion by freezing and evacuating the dispersion to obtain carbon nanotubes coated with surfactant. The carbon nanotubes prepared by the method of the invention are dry, amphiphilic, and surfactant-coated powders that can be dispersed in both aqueous and organic solvents to form stable and uniform dispersions having a high concentration of carbon nanotubes.

Abstract: Dispersible single-walled and multi-walled carbon nanotubes (CNTs) are prepared by dissolving surfactants in water to form a solution; adding carbon nanotubes to the solution to form a mixture; sonicating and agitating the mixture to form a carbon-nanotube/water dispersion; centrifuging the dispersion to remove un-dispersed carbon nanotubes and impurities; repeatedly freezing and heating the CNT dispersion; and, sublimating water in the CNT dispersion by freezing and evacuating the dispersion to obtain carbon nanotubes coated with surfactant. The carbon nanotubes prepared by the method of the invention are dry, amphiphilic, and surfactant-coated powders that can be dispersed in both aqueous and organic solvents to form stable and uniform dispersions having a high concentration of carbon nanotubes.