Hollow fiber membranes having improved toughness and durability are prepared using a vinylidene fluoride polymer-containing component, such as Kynaro resins, having relatively low crystallinity. One aspect of the invention provides a membrane in the form of a fiber, wherein i) the fiber has a porous wall of a polymeric component enclosing a central hollow space extending the length of the fiber, ii) the polymeric component has a crystallinity as determined by wide angle x-ray diffraction of less than about 35%, iii) the polymeric component is comprised of at least one homopolymer or copolymer of vinylidene fluoride and iv) the membrane has an energy to break of at least about 0.5 J per square mm of membrane cross section.

An optical fiber is a linear radiator uniform in the longer direction thereof, and a lighting device uses the optical fiber. The optical fiber is a lighting fiber having a core and a cladding. In the fiber, as the cladding, there is used a polymer obtained by polymerizing a polymerizing ingredient containing 90% or more by weight of vinylidene fluoride, and the cladding has a crystallinity of 45% to 52%.

An optical fiber is a linear radiator uniform in the longer direction thereof, and a lighting device uses the optical fiber. The optical fiber is a lighting fiber having a core and a cladding. In the fiber, as the cladding, there is used a polymer obtained by polymerizing a polymerizing ingredient containing 90% or more by weight of vinylidene fluoride, and the cladding has a crystallinity of 45% to 52%.

Microscale and nanoscale tubular structures are provided including rheological fluids in their interior volume and including at least one electroactive component. Multiple tubular structures are provided, including simple hollow tube structures; core/shell structures, wherein the tube includes a tubular outer shell with a core extending axially therein; concentric tube or coaxial tube structures, wherein the tube includes a tubular outer shell and one or more concentric tubes extending axially therein; and core/concentric tube structures, wherein concentric tubes further include a core extending axially therein, thus having a core and two or more tubes surrounding the core. The tubular structures are formed by electrospinning and special spinnerets are provided. The tubular structures form fabrics for beneficial uses.

Microscale and nanoscale tubular structures are provided including rheological fluids in their interior volume and including at least one electroactive component. Multiple tubular structures are provided, including simple hollow tube structures; core/shell structures, wherein the tube includes a tubular outer shell with a core extending axially therein; concentric tube or coaxial tube structures, wherein the tube includes a tubular outer shell and one or more concentric tubes extending axially therein; and core/concentric tube structures, wherein concentric tubes further include a core extending axially therein, thus having a core and two or more tubes surrounding the core. The tubular structures are formed by electrospinning and special spinnerets are provided. The tubular structures form fabrics for beneficial uses.

Among other things, the inventive subject matter generally relates to nonwoven textiles consisting of webs of superfine fibers, i.e., fibers with diameters in nanoscale or micronscale ranges, for use in articles that have, for example a predetermined degree of waterproofness with breathability, or windproofness with breathability.

A hollow-fiber membrane according to an aspect of the present disclosure contains a polytetrafluoroethylene or a modified polytetrafluoroethylene as a main component and has an average outer diameter of 1 mm or less and an average inner diameter of 0.5 mm or less. In a measurement of a heat of fusion of the polytetrafluoroethylene or the modified polytetrafluoroethylene with a differential scanning calorimeter, when the polytetrafluoroethylene or modified polytetrafluoroethylene is subjected to a first step of heating from room temperature to 365° C., a second step of cooling from 365° C. to 350° C., maintaining the temperature, subsequently cooling from 350° C. to 330° C., and further cooling from 330° C. to 305° C., and a third step of cooling from 305° C. to 245° C. at a rate of −50° C./min and subsequently heating from 245° C. to 365° C. at a rate of 10° C./min, a heat of fusion from 296° C. to 343° C. in the third step is 30.0 J/g or more and 45.0 J/g or less.

A composite electrode includes two or more types of fibers forming a fiber network, comprising at least a first type of fibers and a second type of fibers. The first type of fibers comprises a first polymer and a first type of particles. The second type of fibers comprises a second polymer and a second type of particles. The second polymer is same as or different from the first polymer. The second type of particles are same as or different from the first type of particles.

Provided are: a filter medium with high dust collection efficiency, low pressure loss, and a long lifespan; and a filter material used for the filter medium. This composite structure includes ultrafine fibers having a fiber diameter of less than 500 nm, and beads. The outermost surface of the composite structure has at least 500/mm.sup.2 of beads with a diameter of 5 μm or more. The ultrafine fibers and the beads preferably have the same component.

Provided are: a filter medium with high dust collection efficiency, low pressure loss, and a long lifespan; and a filter material used for the filter medium. This composite structure includes ultrafine fibers having a fiber diameter of less than 500 nm, and beads. The outermost surface of the composite structure has at least 500/mm.sup.2 of beads with a diameter of 5 μm or more. The ultrafine fibers and the beads preferably have the same component.