A preparation method for an yttrium aluminum garnet continuous fiber. The method prepares a spinnable precursor sol by utilizing an Al.sub.13 colloidal particles contained alumina sol, γ-AlOOH nano-dispersion, yttria sol, glacial acetic acid and polyvinylpyrrolidone, then prepares a gel continuous fiber by adopting a dry spinning technique, and carries out a heat treatment to obtain the yttrium aluminum garnet continuous fiber.

A method of making polyurethane or polyurethane urea strands containing siloxane in the polyurethane or polyurethane urea backbone including the steps of: (a) reacting a macroglycol with a diisocyanate to form a prepolymer; (b) reacting the prepolymer with a diamine to form a spinning solution; (c) spinning the spinning solution to form polyurethane or polyurethane urea strands, wherein: i. a diol-polydimethylsiloxane is reacted with the macroglycol and the diisocyanate in step (a); ii. a diamine-polydimethylsiloxane is reacted with the prepolymer prior to the reaction of the prepolymer with the diamine in step (b); or iii. a diamine-polydimethylsiloxane is reacted at the same time as the prepolymer and diamine in step (b), and wherein the polyurethane or polyurethane urea strands comprise less than or equal to 6% of siloxane by weight based on the weight of the polyurethane or polyurethane urea strands and elastic fibers made thereby. An elastic fiber including two or more polyurethane or polyurethane urea strands including siloxane in the polyurethane or polyurethane urea backbone that are bundled together, wherein the siloxane is present in an amount of greater than or equal to 0.01% and less than or equal to 4.0% by weight based on the weight of the fiber. In some aspects, the siloxane is free of urethane radicals.

A method of making polyurethane or polyurethane urea strands containing siloxane in the polyurethane or polyurethane urea backbone including the steps of: (a) reacting a macroglycol with a diisocyanate to form a prepolymer; (b) reacting the prepolymer with a diamine to form a spinning solution; (c) spinning the spinning solution to form polyurethane or polyurethane urea strands, wherein: i. a diol-polydimethylsiloxane is reacted with the macroglycol and the diisocyanate in step (a); ii. a diamine-polydimethylsiloxane is reacted with the prepolymer prior to the reaction of the prepolymer with the diamine in step (b); or iii. a diamine-polydimethylsiloxane is reacted at the same time as the prepolymer and diamine in step (b), and wherein the polyurethane or polyurethane urea strands comprise less than or equal to 6% of siloxane by weight based on the weight of the polyurethane or polyurethane urea strands and elastic fibers made thereby. An elastic fiber including two or more polyurethane or polyurethane urea strands including siloxane in the polyurethane or polyurethane urea backbone that are bundled together, wherein the siloxane is present in an amount of greater than or equal to 0.01% and less than or equal to 4.0% by weight based on the weight of the fiber. In some aspects, the siloxane is free of urethane radicals.

Disclosed in the present disclosure are a self-fused graphene fiber and a method of preparing the same. Dried graphene oxide fibers are soaked in a solvent to swell and then the fibers are pulled out and coalesced. After being dried, the graphene oxide fibers are fused together, and then are further reduced to obtain a self-fused graphene fiber. The entire self-fusion process can be quickly finished within one minute without adding any additional binder. The operation is simple and time-saving. The process is environmentally friendly; the bond strength is high, and the excellent properties such as outstanding mechanical strength and electrical conductivity of the graphene fibers themselves can be maintained. The present disclosure has great research and application value for further preparation of two-dimensional graphene fabrics or three-dimensional network bulks with excellent performance.

Disclosed in the present disclosure are a self-fused graphene fiber and a method of preparing the same. Dried graphene oxide fibers are soaked in a solvent to swell and then the fibers are pulled out and coalesced. After being dried, the graphene oxide fibers are fused together, and then are further reduced to obtain a self-fused graphene fiber. The entire self-fusion process can be quickly finished within one minute without adding any additional binder. The operation is simple and time-saving. The process is environmentally friendly; the bond strength is high, and the excellent properties such as outstanding mechanical strength and electrical conductivity of the graphene fibers themselves can be maintained. The present disclosure has great research and application value for further preparation of two-dimensional graphene fabrics or three-dimensional network bulks with excellent performance.

According to an embodiment, an electrospinning apparatus includes: a transport roll; and a head unit. The transport roll is a roll that transports a substrate. The transport has a transport surface that is in contact with the substrate when transporting the substrate. The transport surface of the transport roll has a surface roughness Ra of 1.6 or less. The head unit ejects a raw material liquid of fiber toward the substrate transported by the transport roll to form a film of the fiber on the substrate.

According to an embodiment, an electrospinning apparatus includes: a transport roll; and a head unit. The transport roll is a roll that transports a substrate. The transport has a transport surface that is in contact with the substrate when transporting the substrate. The transport surface of the transport roll has a surface roughness Ra of 1.6 or less. The head unit ejects a raw material liquid of fiber toward the substrate transported by the transport roll to form a film of the fiber on the substrate.

Provided are a high-entropy carbide ceramic, a rare earth-containing high-entropy carbide ceramic, fibers thereof, precursors thereof, and preparation methods thereof. The precursor includes at least four elements selected from Ti, Zr, Hf, V, Nb, Ta, Mo, and W, with each metal element accounting for 5-35% of the total molar quantity of metal elements in the precursor. The rare earth-containing high-entropy carbide ceramic precursor includes at least four transition metal elements and at least one rare-earth metal element. The high-entropy ceramic is a single-crystal-phase high-performance ceramic prepared from the precursor, with each element being homogenously distributed at molecular level. The method for preparing the high-entropy ceramic fiber includes uniformly mixing high-entropy carbide ceramic precursor containing target metal elements with spinning aid and solvent to prepare a spinnable precursor solution, followed by spinning, pyrolyzation, and high-temperature solid solution to prepare the high-entropy carbide ceramic fiber.

Provided are a high-entropy carbide ceramic, a rare earth-containing high-entropy carbide ceramic, fibers thereof, precursors thereof, and preparation methods thereof. The precursor includes at least four elements selected from Ti, Zr, Hf, V, Nb, Ta, Mo, and W, with each metal element accounting for 5-35% of the total molar quantity of metal elements in the precursor. The rare earth-containing high-entropy carbide ceramic precursor includes at least four transition metal elements and at least one rare-earth metal element. The high-entropy ceramic is a single-crystal-phase high-performance ceramic prepared from the precursor, with each element being homogenously distributed at molecular level. The method for preparing the high-entropy ceramic fiber includes uniformly mixing high-entropy carbide ceramic precursor containing target metal elements with spinning aid and solvent to prepare a spinnable precursor solution, followed by spinning, pyrolyzation, and high-temperature solid solution to prepare the high-entropy carbide ceramic fiber.

A fiber assembly includes, on a main surface of a support sheet subjected to a release treatment, a warp yarn group in which a plurality of warp yarns including a polymer material are arranged, and a weft yarn group in which a plurality of weft yarns including a polymer material are arranged. The warp yarn group and the weft yarn group form a plurality of first contact portion regions and a plurality of non-contact portion regions. Each of the plurality of first contact portion regions is a region in which at least one of the plurality of warp yarns is integrated with at least one of the plurality of weft yarns. Each of the plurality of warp yarns has a line width of 1 μm to 10 μm, inclusive, and each of the plurality of weft yarns has a line width of 1 μm to 10 μm, inclusive. At least one of the plurality of first contact portion regions has a fiber density higher than that of at least one of the plurality of non-contact portion regions. Two of the plurality of warp yarns or two of the plurality of weft yarns have a spacing of 5 μm or more and 1000 μm or less in at least one of the plurality of first contact portion regions. Two of the plurality of warp yarns or two of the plurality of weft yarns have a spacing of 2000 μm or more in at least one of the plurality of non-contact portion regions.