A manufacturing method for a carbon fiber includes: performing an emulsification step that includes uniformly mixing a silicone oil composition and an emulsifier to form an oiling agent, in which the silicone oil composition includes γ-divinyltriamine propylmethyldimethoxyl silane and N-(β-aminoethyl)-γ-aminopropylmethylbimethoxy silane; performing an oiling step that includes soaking a carbon raw filament in the oiling agent, such that the oiling agent is adhered to a surface of the carbon raw filament to form a carbon fiber precursor; and performing a calcination step on the carbon fiber precursor, such that the carbon fiber is formed.

A manufacturing method for a carbon fiber includes: performing an emulsification step that includes uniformly mixing a silicone oil composition and an emulsifier to form an oiling agent, in which the silicone oil composition includes γ-divinyltriamine propylmethyldimethoxyl silane and N-(β-aminoethyl)-γ-aminopropylmethylbimethoxy silane; performing an oiling step that includes soaking a carbon raw filament in the oiling agent, such that the oiling agent is adhered to a surface of the carbon raw filament to form a carbon fiber precursor; and performing a calcination step on the carbon fiber precursor, such that the carbon fiber is formed.

The present application provides methods for producing polybenzimidazole carbon fiber that does not require infusibilization treatment.

The present application provides methods for producing polybenzimidazole carbon fiber that does not require infusibilization treatment.

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).

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).

Hybrid carbon nanofiber (Cnf) products (e.g., mats, yarns, webs, etc.) and methods of fabricating the same are provided. The hybrid Cnf products are flexible and lightweight and have high thermal conductivity. An electrospinning process can be used to fabricate the hybrid Cnf products and can include preparation of an electrospinning solution, electrospinning, and carbonization (e.g., under a vacuum condition).

In an infusibilized polyphenylene ether fiber of the present disclosure, an absorbance height ratio (A/B) between an absorbance height A at a wave number of 1694 cm.sup.−1 derived from C═O stretching vibration and an absorbance height B at a wave number of 1600 cm.sup.−1 derived from skeleton vibration due to carbon-carbon stretching of a benzene ring is 0.25 or more, and an absorbance height ratio (C/B) between an absorbance height C at a wave number of 1661 cm.sup.−1 derived from C═O stretching vibration and an absorbance height B at a wave number of 1600 cm.sup.−1 derived from skeleton vibration due to carbon-carbon stretching of a benzene ring is 0.75 or less, as measured by infrared spectroscopy.

In an infusibilized polyphenylene ether fiber of the present disclosure, an absorbance height ratio (A/B) between an absorbance height A at a wave number of 1694 cm.sup.−1 derived from C═O stretching vibration and an absorbance height B at a wave number of 1600 cm.sup.−1 derived from skeleton vibration due to carbon-carbon stretching of a benzene ring is 0.25 or more, and an absorbance height ratio (C/B) between an absorbance height C at a wave number of 1661 cm.sup.−1 derived from C═O stretching vibration and an absorbance height B at a wave number of 1600 cm.sup.−1 derived from skeleton vibration due to carbon-carbon stretching of a benzene ring is 0.75 or less, as measured by infrared spectroscopy.

[Problem] To provide: a carbon fiber precursor fiber that can efficiently produce a carbon fiber at a low cost which is excellent in mechanical strengths even without an infusibilization treatment; a carbon fiber; and a method for producing the carbon fiber.

[Solution] A carbon fiber precursor fiber of the present invention includes a polymer containing a constituent unit represented by General Formula (1) below:

##STR00001## where in the General Formula (1), X and Y each independently represent a divalent substituent, a single bond, or a structure forming a fused ring by sharing one side of two adjacent rings, and the divalent substituent is selected from the group consisting of —O—, —S—, —OSO—, —NH—, —CO—, —CH.sub.2—, and —CH(CH.sub.3).sub.2—.