8 results about "Silicon nanotube" patented technology

The invention discloses a silicon-carbon material and a preparation method and application thereof, belongs to the technical field of negative electrode materials, and overcomes the defect of high volume expansion rate of a silicon-based material in the prior art. The silicon-carbon material provided by the invention comprises porous carbon and silicon deposited in porous carbon channels; the porous carbon comprises mesopores and macropores, the pore diameter of the mesopores is greater than 10nm and less than or equal to 50nm, and the pore diameter of the macropores is greater than 50nm and less than or equal to 100nm; based on the total volume of the pores in the porous carbon, the volume fraction of the mesopores is 50%-75%, and the volume fraction of the macropores is 10%-20%; and the silicon deposited in the mesopores and the macropores is a hollow silicon nanotube. Silicon in the silicon-carbon material mainly exists in the form of hollow silicon nanotubes, and during lithium intercalation expansion, since expansion spaces are reserved in the hollow nanotubes, the lithium intercalation expansion of the whole silicon-carbon material is reduced.

The invention relates to a multilayer layered mesoporous silicon nanotube and a preparation method and application thereof, and the preparation method comprises the following steps: mixing a single-chain surfactant, a double-chain surfactant and water to obtain a mixed solution; mixing the obtained mixed solution with alkali and a silane precursor for reaction; and washing a reaction product obtained by the reaction, and roasting at high temperature to obtain the multilayer layered mesoporous silicon nanotube. Compared with the prior art, the prepared mesoporous silicon nanotube has a long-range ordered layered mesoporous structure, the outer tube diameter is 20-60 nm, the interlayer spacing is 2.0-20 nm, the specific surface area is 100-1200 m < 2 > / g, the mesoporous silicon nanotube is expected to be applied to the field of heat insulation, and the preparation method is high in controllability and suitable for preparation of layered mesoporous silicon of a series of sizes.

The present application belongs to the field of one-dimensional size nanometer material preparation and application, and particularly relates to a preparation method of a size-controllable hollow silica nanometer tube coating and application of the coating in a super-hydrophobic self-cleaning anti-reflection coating. The coating is prepared by high-temperature treatment of poly(methyl hydrogen siloxane) in an alkaline environment, and the specific preparation method is as follows: preparing a n-heptane or cyclohexane solution of poly(methyl hydrogen siloxane); placing the n-heptane or cyclohexane solution of poly(methyl hydrogen siloxane), ammonia water, ultrapure water and a substrate in a reaction kettle; adjusting the volume ratio of the ammonia water to the ultrapure water and the reaction temperature to prepare hollow nanometer tube coatings with different sizes. The average light transmittance of the coating prepared by the present application can reach 92.44% in the range of 400-800 nm, which is 2.4% higher than that of the substrate, the water contact angle is 156.1°, and the rolling angle is 0.75°. The silica nanometer tube coating has excellent self-cleaning properties.

The invention relates to a preparation method of a silicon nanotube array. The preparation method comprises the following steps: providing a silicon substrate, preparing a nanotube array pattern on the surface of the silicon substrate, and carrying out deep silicon etching by utilizing a Bosh process to form the silicon nanotube array. Wherein in the process of performing deep silicon etching by using the Bosh process, the etching gas is SF6, the passivation gas is C4F8, and the flow ratio R of the SF6 to the C4F8 is 0.8-0.9; the etching power P ranges from 600 W to 800 W; the etching depth D meets the relational expression that D is in direct proportion to PR / (1 + R2). According to the preparation method of the silicon nanotube array disclosed by the invention, the silicon nanotube array of which the side wall roughness is less than 10nm and the depth-to-width ratio is not less than 20: 1 can be obtained in an atypical parameter interval in the prior art. Moreover, according to the method disclosed by the invention, parameter adjustment is carried out based on a relational expression D < PR / (1 + R2), the method is different from a traditional process regulation and control mode depending on a trial-and-error method, and proper process parameters can be quickly and accurately found for the preparation process of the silicon nanotube array with the smooth side wall and the high aspect ratio.

The application discloses a method for preparing a mixed matrix reverse osmosis membrane by using mesoporous silicon nanotubes, and the method is implemented according to the following steps: 1) obtaining a silicon solid rod by using Pluronic F127 block copolymer and cetyltrimethylammonium bromide under the participation of tetraethyl orthosilicate, then removing the surfactant by using hydrochloric acid to further obtain a mesoporous material, and finally etching the mesoporous material by using polyethyleneimine to obtain the mesoporous silicon nanotubes; 2) then, the synthesized mesoporous silicon nanotubes are added into an aqueous phase solution containing m-phenylenediamine and uniformly dispersed, so that the content of the mesoporous silicon nanotubes in the aqueous phase solution is 0.005% w / v to 0.04% w / v, and an aqueous phase solution is obtained; 3) the aqueous phase solution obtained through the step 2) and a uniform benzenetriyl chloride oil phase solution are used to form a polyamide layer on a support layer by using an interfacial polymerization method, and a mixed matrix reverse osmosis membrane is obtained. The method can significantly improve the flux of the reverse osmosis membrane while maintaining a high rejection rate.

The present application relates to the technical field of fluorine-free anti-dripping agent, and particularly relates to a high-efficiency fluorine-free anti-dripping agent and a preparation method thereof, which comprises high-aspect-ratio silicon nanotubes, low-aspect-ratio silicon nanotubes, modified PVP-b-PCL and a composite stabilizer. The high-aspect-ratio silicon nanotubes are grafted with PEG, which effectively prevents PBT molecules from approaching the surface of the silicon nanotubes, thereby controlling the shrinkage of the material after molding. The low-aspect-ratio silicon nanotubes are added to prevent the high-aspect-ratio silicon nanotubes from directly contacting and tightly winding to cause agglomeration, and the introduction of the low-aspect-ratio silicon nanotubes can significantly improve the zero-shear viscosity of the polymer melt, thereby avoiding the warping and distortion of the product. The PCL segment of the modified PVP-b-PCL helps the high-aspect-ratio silicon nanotubes to better integrate into the PBT matrix, and the PVP segment prevents the short nanotubes from being aggregated due to polarity, so that the low-aspect-ratio silicon nanotubes can stably exist around the high-aspect-ratio silicon nanotubes to form a uniform mixture.

The invention relates to the technical field of fluoride-free anti-dripping agents, in particular to an efficient fluoride-free anti-dripping agent and a preparation method thereof.The efficient fluoride-free anti-dripping agent comprises a high-length-diameter-ratio silicon nanotube, a low-length-diameter-ratio silicon nanotube, modified PVP-b-PCL and a compound stabilizer. The high-length-diameter-ratio silicon nanotube is grafted with PEG, PBT molecules are effectively prevented from being linked to the surface of the silicon nanotube, and then the shrinkage rate of the formed material is controlled. The addition of the low-length-diameter-ratio silicon nanotubes prevents agglomeration caused by direct contact and tight winding of the high-length-diameter-ratio silicon nanotubes, and the introduction of the low-length-diameter-ratio silicon nanotubes can significantly improve the zero shear viscosity of a polymer melt and avoid warping and twisting of a product. The PCL chain segment of the modified PVP-b-PCL helps the high-length-diameter-ratio silicon nanotubes to be better fused into the PBT matrix, and the PVP segment prevents short nanotubes from mutually gathering due to polarity, so that the low-length-diameter-ratio silicon nanotubes can stably exist around the high-length-diameter-ratio silicon nanotubes to form a uniform mixture.

Silicon carbide nanowires on carbon species and methods of making and using thereof, and, more particularly, silicon carbide nanowires on coal, graphene, graphite, and fibrous carbon species and methods of making and using thereof. Flash Joule heating and / or microwave reactions are performed in which silicon carbide nanotubes are grown on the surface of a coal-based feedstock, a carbon fiber-based feedstock, or a graphene or graphite feedstock derived from coal or carbon fiber.