Three dimensional nanofiber structures are provided and methods of production thereof.

An apparatus for making nonwoven has a spinning device for spinning continuous filaments and moving the spun filaments in a vertical travel direction along a vertical travel path and a mesh belt below the spinning device, traveling in a horizontal direction, and having a multiplicity of vertically throughgoing openings distributed generally uniformly over its surface and of which a portion are plugged. A cooler and a stretcher are provided along the path downstream of the spinning device and above the belt for cooling and stretching the filaments and depositing the cooled and stretched filaments at a predetermined deposition location on the belt. A blower underneath the belt at the deposition location aspirates air through the openings and thereby holds the deposited filaments down on the belt.

An apparatus for making nonwoven has a spinning device for spinning continuous filaments and moving the spun filaments in a vertical travel direction along a vertical travel path and a mesh belt below the spinning device, traveling in a horizontal direction, and having a multiplicity of vertically throughgoing openings distributed generally uniformly over its surface and of which a portion are plugged. A cooler and a stretcher are provided along the path downstream of the spinning device and above the belt for cooling and stretching the filaments and depositing the cooled and stretched filaments at a predetermined deposition location on the belt. A blower underneath the belt at the deposition location aspirates air through the openings and thereby holds the deposited filaments down on the belt.

Three dimensional nanofiber structures are provided and methods of production thereof.

Three dimensional nanofiber structures are provided and methods of production thereof.

A method of producing carbon nanofibers is disclosed that substantially impacts the carbon nanofibers' chemical and physical properties. Such carbon nanofibers include a semi-graphitic carbon material characterized by wavy graphite planes ranging from 0.1 nm to 1 nm and oriented parallel to an axis of a respective carbon nanofiber, the semi-graphitic carbon material also being characterized by an inclusion of 4 to 10 atomic percent of nitrogen heteroatoms, the nitrogen heteroatoms including a combined percentage of quaternary and pyridinic nitrogen groups equal to or greater than 60% of the nitrogen heteroatoms. The method of manufacture includes, for example, preparing a Polyacrylonitrile (PAN) based precursor solution, providing the PAN-based precursor solution to a spinneret and then performing an electro-spinning operation on the PAN-based precursor solution to create the one or more PAN-based nanofibers. The electro-spinning operation includes passing the PAN-based precursor solution from the spinneret to a collector at a distance between 1 cm to 30 cm while providing an Alternating Current (AC) voltage between the spinneret and the collector, the AC voltage including a frequency ranging from 20 Hz to 100,000 Hz and either a Peak-to-Peak (P-P) voltage ranging from 100 V to 30,000 V or a Root-Mean-Square (RMS) voltage ranging from 100 V to 30,000 V. Afterwards, post-electro-spinning operations, stabilizing treatments and pyrolysis treatments are performed.

Techniques are described for controlling widths of nanofiber sheets drawn from a nanofiber forest. Nanofiber sheet width can be controlled by dividing or sectioning the nanofiber sheet in its as-drawn state into sub-sheets as the sheet is being drawn. A width of a sub-sheet can be controlled or selected so as to contain regions of uniform nanofiber density within a sub-sheet (thereby improving nanofiber yarn consistency) or to isolate an inhomogeneity (whether a discontinuity is the sheet (e.g., a tear) or a variation in density) within a sub-sheet. Techniques for dividing a nanofiber sheet into sub-sheets includes mechanical, corona, and electrical arc techniques.

A method and apparatus fabricate synthetic hair by mixing a raw material to form a mixed material; sterilizing the mixed material to form a sterilized material; melting the sterilized material to form a melted material; yarning the melted material to form a yarn material; sterilizing the yarn material to form an intermediate sterilized yarn; heating the sterilized yarn to form a heated yarn; and sterilizing the heated yarn to form a final sterilized yarn. Sterilizing of the mixed material, the yarn material, and/or the heated yarn includes: sterilizing using an ultraviolet (UV) lamp. Heating of the sterilized yarn is performed by a heating device selected from a heated roller, a heating plate, a steam jet device, and a hot water reservoir. Alternatively, sterilizing of the heated yarn includes: immersing the heated yarn into an immersion device, which includes an antibacterial solution. The final sterilized yarn forms a synthetic hair.

The present disclosure provides a coaxial fiber comprising a cellulose fiber exterior, and a hollow interior, wherein the aerogel occupies the hollow interior of the cellulose fiber. The present disclosure also provides a method of making the coaxial fiber, and a method of maintain a temperature differential in two zones using the coaxial fibers described herein.

The present disclosure provides a coaxial fiber comprising a cellulose fiber exterior, and a hollow interior, wherein the aerogel occupies the hollow interior of the cellulose fiber. The present disclosure also provides a method of making the coaxial fiber, and a method of maintain a temperature differential in two zones using the coaxial fibers described herein.