A crystalline silicon carbide fiber containing silicon carbide and boron nitride, the crystalline silicon carbide fiber having a content of Si of 64% to 72% by weight, a content of C of 28% to 35% by weight, and a content of B of 0.1% to 3.0% by weight, and including, at a surface portion, a composition gradient layer in which a content of silicon carbide increases while a content of boron nitride decreases toward a depth direction.

A method for manufacturing composite fiber of charred vinasse and shell includes steps of: charring a vinasse raw material at 800 to 1000 degrees Celsius to form a charred vinasse material, washing a shell raw material and charring the shell raw material at 1000 to 1400 degrees Celsius to form a charred shell material; mixing the charred vinasse material and the charred shell material in a weight ratio of 60-70:40-30 to form a mixed material, grinding the mixed material, mixing the mixed material and polyester granules in a weight ratio of 10-16:90-84, melting and granulating the mixed material and polyester granules to form primary granules; mixing and melting the primary granules and polyester granules in a weight ratio of 5-20:95-80 and granulating to form mixed granules; melting the mixed granules to spin into a composite fiber.

In order to provide a method for preparing a chalcogenide-carbon nanofiber, capable of implementing oxidation resistance characteristics and process simplification, the present invention provides a method for preparing a chalcogenide-carbon nanofiber and a chalcogenide-carbon nanofiber implemented by using the same, the method comprising the steps of: forming a chalcogenide precursor-organic nanofiber comprising a chalcogenide precursor and an organic material; and forming a chalcogenide-carbon nanofiber by selectively and oxidatively heat treating the chalcogenide precursor-organic nanofiber such that the carbon of the organic material is oxidized and the chalcogenide is reduced at the same time, wherein the oxidation reactivity of the chalcogenide is lower than that of carbon, the selective and oxidative heat treatment is carried out through one heat treatment step instead of a plurality of heat treatment steps, and the chalcogenide can form a chalcogenide-carbon nanofiber having a structure formed with at least one layer according to an oxygen partial pressure at which the selective and oxidative heat treatment is carried out.

In order to provide a method for preparing a chalcogenide-carbon nanofiber, capable of implementing oxidation resistance characteristics and process simplification, the present invention provides a method for preparing a chalcogenide-carbon nanofiber and a chalcogenide-carbon nanofiber implemented by using the same, the method comprising the steps of: forming a chalcogenide precursor-organic nanofiber comprising a chalcogenide precursor and an organic material; and forming a chalcogenide-carbon nanofiber by selectively and oxidatively heat treating the chalcogenide precursor-organic nanofiber such that the carbon of the organic material is oxidized and the chalcogenide is reduced at the same time, wherein the oxidation reactivity of the chalcogenide is lower than that of carbon, the selective and oxidative heat treatment is carried out through one heat treatment step instead of a plurality of heat treatment steps, and the chalcogenide can form a chalcogenide-carbon nanofiber having a structure formed with at least one layer according to an oxygen partial pressure at which the selective and oxidative heat treatment is carried out.

An inorganic fiber-formed article, composed of a mat-shaped inorganic fiber assembly, the inorganic fiber-formed article including needle marks that extend in a direction including a thickness direction of the mat-shaped inorganic fiber assembly, where the needle marks include needle marks A and needle marks B having a diameter smaller than that of the needle marks A, dense portions in which a plurality of the needle marks A lie densely are arranged apart, non-dense portions in which a needle mark density of the needle marks A is lower than that in the dense portions are present between the dense portions in both a first direction which is any mat-surface direction extending through the dense portions and a second direction orthogonal to the first direction, and the needle marks B are present at least in the non-dense portions.

An inorganic fiber-formed article, composed of a mat-shaped inorganic fiber assembly, the inorganic fiber-formed article including needle marks that extend in a direction including a thickness direction of the mat-shaped inorganic fiber assembly, where the needle marks include needle marks A and needle marks B having a diameter smaller than that of the needle marks A, dense portions in which a plurality of the needle marks A lie densely are arranged apart, non-dense portions in which a needle mark density of the needle marks A is lower than that in the dense portions are present between the dense portions in both a first direction which is any mat-surface direction extending through the dense portions and a second direction orthogonal to the first direction, and the needle marks B are present at least in the non-dense portions.

A method for synthesizing silica nanofibers using sound waves is provided. The method includes providing a solution of polyvinyl pyrrolidone, adding sodium citrate and ammonium hydroxide to form a first mixture, adding a silica-based compound to the solution to form a second mixture, and sonicating the second mixture to synthesize a plurality of silica nanofibers having an average cross-sectional diameter of less than 70 nm and having a length on the order of at least several hundred microns. The method can be performed without heating or electrospinning, and instead includes less energy intensive strategies that can be scaled up to an industrial scale. The resulting nanofibers can achieve a decreased mean diameter over conventional fibers. The decreased diameter generally increases the tensile strength of the silica nanofibers, as defects and contaminations decrease with the decreasing diameter.

A method for synthesizing silica nanofibers using sound waves is provided. The method includes providing a solution of polyvinyl pyrrolidone, adding sodium citrate and ammonium hydroxide to form a first mixture, adding a silica-based compound to the solution to form a second mixture, and sonicating the second mixture to synthesize a plurality of silica nanofibers having an average cross-sectional diameter of less than 70 nm and having a length on the order of at least several hundred microns. The method can be performed without heating or electrospinning, and instead includes less energy intensive strategies that can be scaled up to an industrial scale. The resulting nanofibers can achieve a decreased mean diameter over conventional fibers. The decreased diameter generally increases the tensile strength of the silica nanofibers, as defects and contaminations decrease with the decreasing diameter.

Lithium-containing nanofibers, as well as processes for making the same, are disclosed herein. In some embodiments described herein, using high throughput (e.g., gas assisted and/or water based) electrospinning processes produce nanofibers of high energy capacity materials with continuous lithium-containing matrices or discrete crystal domains.

Lithium-containing nanofibers, as well as processes for making the same, are disclosed herein. In some embodiments described herein, using high throughput (e.g., gas assisted and/or water based) electrospinning processes produce nanofibers of high energy capacity materials with continuous lithium-containing matrices or discrete crystal domains.