The present invention provides a porous carbon fiber which has an excellent permeation amount and excellent pressure resistance, which is prevented from the occurrence of detachment or cracking at an interface, and which can exhibit excellent properties needed for use as a support for a fluid separation membrane. The present invention is a porous carbon fiber having a bicontinuous porous structure, wherein

the average value R.sub.ave of the R value of the outer surface and the R value of the inside is 1.0 or more and 1.8 or less,

the absolute value ΔR of the difference between the R value of the outer surface and the R value of the inside is 0.05 or less, and

R value is a carbonization progression degree calculated from a Raman spectrum in accordance with the following formula:

R value=(intensity of scattering spectrum at 1360 cm.sup.−1)/(intensity of scattering spectrum at 1600 cm.sup.−1).

In a method of making a carbon fiber, PAN (poly(acrylonitrile-co methacrylic acid)) is dissolved into a solvent to form a PAN solution. The PAN solution is extruded through a spinneret, thereby generating at least one precursor fiber. The precursor fiber is passed through a cold gelation medium, thereby causing the precursor fiber to gel. The precursor fiber is drawn to a predetermined draw ratio. The precursor fiber is continuously stabilized to form a stabilized fiber. The stabilized fiber is continuously carbonized thereby generating the carbon fiber. The carbon fiber is wound onto a spool. A carbon fiber has a fiber tensile strength in a range of 5.5 GPa to 5.83 GPa. The carbon fiber has a fiber tensile modulus in a range of 350 GPa to 375 GPa. The carbon fiber also has an effective diameter in a range of 5.1 μm to 5.2 μm.

A method of preparing a structure, more particularly, a method of preparing a structure capable of ensuring a space for carrying an electrode active material by a simple method which includes an electrospinning process using a double nozzle electrospinning device and a heat treatment process.

An aqueous liquid of a carbon fiber precursor treatment agent contains a carbon fiber precursor treatment agent and water, the carbon fiber precursor treatment agent containing an amino-modified silicone and a particular nonionic surfactant having a molecular weight distribution (Mw/Mn) of from 1.05 to 1.50. The amino-modified silicone may have a kinematic viscosity at 25° C. of 50 to 4,000 mm.sup.2/s. The carbon fiber precursor treatment agent is adhered to a carbon fiber precursor.

A molybdenum disulfide/graphene/carbon composite material having a hierarchical pore structure includes a composite nanofiber having a diameter of 60 to 500 nm. The composite nanofiber comprises, in mass percentage, 3% to 35% of molybdenum disulfide, 0.2% to 10% of graphene, and 60% to 95% of carbon. The composite nanofiber has a hierarchical pore structure distributed along the axial direction, and has a pore diameter continuously distributed between 0.1 nm and 5 μm and an average pore diameter between 1.5 nm and 25 nm. On the basis of the pore volume, in the hierarchical pore structure, a micropore structure accounts for 25% to 60%, and a mesoporous structure accounts for 40% to 75%. The microporous structure is distributed on the surface of the nanofiber and the pore wall of the mesoporous structure.

A method of producing an oxidized fiber bundle includes heat-treating an acrylic fiber bundle aligned in a heat treatment chamber in which hot air is circulated while causing the acrylic fiber bundle to run on direction-changing rollers disposed on both ends of an outside of the heat treatment chamber, wherein first hot air is supplied in a direction substantially parallel to a running direction of the acrylic fiber bundle, and second hot air is supplied from above the acrylic fiber bundle at an angle of 20 to 160° with respect to a wind direction of the first hot air, so that the second hot air passes at least a part of a running acrylic fiber bundle in a longitudinal direction.

A method of producing an oxidized fiber bundle includes heat-treating an acrylic fiber bundle aligned in a heat treatment chamber in which hot air is circulated while causing the acrylic fiber bundle to run on direction-changing rollers disposed on both ends of an outside of the heat treatment chamber, wherein first hot air is supplied in a direction substantially parallel to a running direction of the acrylic fiber bundle, and second hot air is supplied from above the acrylic fiber bundle at an angle of 20 to 160° with respect to a wind direction of the first hot air, so that the second hot air passes at least a part of a running acrylic fiber bundle in a longitudinal direction.

The present invention discloses a method for preparing graphene nanofibers and non-woven fabrics using a fluid with a ultra-high draw ratio by means of a high-voltage electrospinning method. Compared with other methods for preparing graphene fibers (such as wet spinning, air-assisted spinning, etc.), the graphene fibers obtained by the present method have smaller diameters (about 100 nm to 500 nm) and a higher yield. The fibers themselves have better mechanical and electrical properties. The invention discloses a method for preparing ultra-fine graphene nanofibers and non-woven fabrics by electrospinning a mixed spinning liquid system of polymer and graphene oxide (the polymer is sodium polyacrylate). This method is highly efficient and environmentally friendly, and the resulted graphene nanofibers are the thinnest graphene fibers as currently known.

The present invention discloses a method for preparing graphene nanofibers and non-woven fabrics using a fluid with a ultra-high draw ratio by means of a high-voltage electrospinning method. Compared with other methods for preparing graphene fibers (such as wet spinning, air-assisted spinning, etc.), the graphene fibers obtained by the present method have smaller diameters (about 100 nm to 500 nm) and a higher yield. The fibers themselves have better mechanical and electrical properties. The invention discloses a method for preparing ultra-fine graphene nanofibers and non-woven fabrics by electrospinning a mixed spinning liquid system of polymer and graphene oxide (the polymer is sodium polyacrylate). This method is highly efficient and environmentally friendly, and the resulted graphene nanofibers are the thinnest graphene fibers as currently known.

The present invention discloses a method for preparing graphene nanofibers and non-woven fabrics using a fluid with a ultra-high draw ratio by means of a high-voltage electrospinning method. Compared with other methods for preparing graphene fibers (such as wet spinning, air-assisted spinning, etc.), the graphene fibers obtained by the present method have smaller diameters (about 100 nm to 500 nm) and a higher yield. The fibers themselves have better mechanical and electrical properties. The invention discloses a method for preparing ultra-fine graphene nanofibers and non-woven fabrics by electrospinning a mixed spinning liquid system of polymer and graphene oxide (the polymer is sodium polyacrylate). This method is highly efficient and environmentally friendly, and the resulted graphene nanofibers are the thinnest graphene fibers as currently known.