A high dielectric contrast composition for particle formation that includes a high dielectric solvent, and a polymer dissolved into the high dielectric solvent. A method of forming particles including dissolving a polymer in a high dielectric solvent to form a high dielectric composition, and dielectrophoretically spinning the high dielectric composition in an electric field to form particles.

Disclosed herein are polycarbonate fibers and fibrous substrates, such as papers, containing such fibers. The polycarbonate fibers are produced from a polymeric composition comprising a cross-linkable polycarbonate containing endgroups derived from a monofunctional benzophenone or containing repeating units derived from a difunctional benzophenone. The polycarbonate fibers can be combined with other fibers to form the fibrous substrate. Upon exposure to ultraviolet light, crosslinking of the polycarbonate fibers will occur, improving various properties of the fibrous substrate.

Disclosed herein are polycarbonate fibers and fibrous substrates, such as papers, containing such fibers. The polycarbonate fibers are produced from a polymeric composition comprising a cross-linkable polycarbonate containing endgroups derived from a monofunctional benzophenone or containing repeating units derived from a difunctional benzophenone. The polycarbonate fibers can be combined with other fibers to form the fibrous substrate. Upon exposure to ultraviolet light, crosslinking of the polycarbonate fibers will occur, improving various properties of the fibrous substrate.

Various embodiments may relate to a method of forming a fiber. The method may include forming a tube using a thermal drawing process. The method may also include providing one or more mixtures into the tube. The method may further include freezing the one or more mixtures within the tube using a freeze-casting process such that a first plurality of walls formed by MXene sheets and a second plurality of walls formed by nanomaterials, the MXene sheets and the nanomaterials comprised in the one or more mixtures, define a plurality of spaces within the tube, thereby forming the fiber.

Various embodiments may relate to a method of forming a fiber. The method may include forming a tube using a thermal drawing process. The method may also include providing one or more mixtures into the tube. The method may further include freezing the one or more mixtures within the tube using a freeze-casting process such that a first plurality of walls formed by MXene sheets and a second plurality of walls formed by nanomaterials, the MXene sheets and the nanomaterials comprised in the one or more mixtures, define a plurality of spaces within the tube, thereby forming the fiber.

Provided are a polycarbonate fiber having a specific orientation degree and/or a specific birefringence value, a fiber structure as well as a resin composite body. The polycarbonate fiber may have an orientation degree (ft) of lower than 0.70, the orientation degree (ft) being defined by the following formula: ft=1(1.0/C).sup.2, C: obtained sonic velocity (km/sec), and may have a birefringence value of 0.04 or lower. The polycarbonate fiber may comprise a polycarbonate resin having a number-average molecular weight (Mn) of from 12000 to 40000 and/or a weight-average molecular weight (Mw) of from 25000 to 80000.