An acrylonitrile-containing fiber includes 100 parts by mass of a polymer including at least 15 parts by mass of acrylonitrile; and 1.0 to 50 parts by mass of a water absorbent resin having a pure water absorption capacity (g/g) with respect to its own weight of at least 10 but less than 100, wherein the fiber is dyeable with a disperse dye.

An acrylonitrile-containing fiber includes 100 parts by mass of a polymer including at least 15 parts by mass of acrylonitrile; and 1.0 to 50 parts by mass of a water absorbent resin having a pure water absorption capacity (g/g) with respect to its own weight of at least 10 but less than 100, wherein the fiber is dyeable with a disperse dye.

The present invention provides a carbon membrane for fluid separation that can suppress the breakage of a carbon membrane installed in a separation module during a vacuum desorption step before permeation of a fluid or during permeation of a fluid. The present invention provides a carbon membrane for fluid separation including a porous carbon support and a dense carbon layer provided on the porous carbon support, wherein the porous carbon support has an R.sub.s value of 1.0 or less, where the R.sub.s value is an R value (peak intensity of D-band (1360 cm.sup.1)/peak intensity of G-band (1580 cm.sup.1)) calculated from a Raman spectrum.

Disclosed are methods for preparing a lignin/poly(vinyl alcohol) (PVA) fiber and for preparing a lignin/polyacrylonitrile (PAN) fiber. The methods can comprise adding a dope of lignin and PVA or a dope of lignin and PAN to a coagulation bath containing a solvent comprising one or more components, wherein the one or more components are present in the solvent in concentrations based on the hydrogen bonding character (f.sub.H) of the solvent, the polar character (f.sub.P) of the solvent, and the dispersive character (f.sub.D) of the solvent; and gel-spinning a lignin/PVA fiber or a lignin/PAN fiber from the coagulation bath.

Disclosed are methods for preparing a lignin/poly(vinyl alcohol) (PVA) fiber and for preparing a lignin/polyacrylonitrile (PAN) fiber. The methods can comprise adding a dope of lignin and PVA or a dope of lignin and PAN to a coagulation bath containing a solvent comprising one or more components, wherein the one or more components are present in the solvent in concentrations based on the hydrogen bonding character (f.sub.H) of the solvent, the polar character (f.sub.P) of the solvent, and the dispersive character (f.sub.D) of the solvent; and gel-spinning a lignin/PVA fiber or a lignin/PAN fiber from the coagulation bath.

Disclosed are polymer nanofiber sensors for detecting gas, which generates visible color change although a specific gas having a concentration of less than 1 ppm is exposed to the sensor in a short time, in which it is impossible to detect the gas using existing colorimetric sensors, through securing high surface area and porosity, and a method of the same.

Disclosed are polymer nanofiber sensors for detecting gas, which generates visible color change although a specific gas having a concentration of less than 1 ppm is exposed to the sensor in a short time, in which it is impossible to detect the gas using existing colorimetric sensors, through securing high surface area and porosity, and a method of the same.

Methods of producing a continuous carbon fiber for use in composites having enhanced moldability are provided. A continuous precursor fiber is formed that has a sheath and a core. The sheath includes a first polymer material. The core includes a second polymer material and a plurality of discrete regions distributed within the second polymer material. The discrete regions include a third polymer material. After the continuous precursor fiber is heated for carbonization and graphitization, the continuous precursor fiber forms a continuous carbon fiber having a plurality of discrete weak regions corresponding to the plurality of discrete regions in the core. Carbon fiber composites made from such modified continuous carbon fibers having enhanced moldability are also provided.

Methods of producing a continuous carbon fiber for use in composites having enhanced moldability are provided. A continuous precursor fiber is formed that has a sheath and a core. The sheath includes a first polymer material. The core includes a second polymer material and a plurality of discrete regions distributed within the second polymer material. The discrete regions include a third polymer material. After the continuous precursor fiber is heated for carbonization and graphitization, the continuous precursor fiber forms a continuous carbon fiber having a plurality of discrete weak regions corresponding to the plurality of discrete regions in the core. Carbon fiber composites made from such modified continuous carbon fibers having enhanced moldability are also provided.

A fiber structure includes a fiber thread including a plurality of monofilaments juxtaposed to and combined with each other. Each of the monofilaments has a hollow shape. Each of the monofilaments is made of an aerogel and an artificial polymer. The aerogel and the artificial polymer are mixed together.