University of Texas System

Sergey Li

Ray H Baughman

Anvar A Zakhidov

Mei Zhang

Shaoli Fang

Ali E Aliev

Chris Williams

Kenneth Ross Atkinson

Alexander Zakhidov

Rashmi Nanjundaswamy

A nanofiber yarn that includes a plurality of nanofibers twisted into a yarn along an alignment axis. The nanofibers of the plurality of nanofibers have a ratio of nanofiber length to nanofiber circumference of at least 50. The yarn has a helix angle measured relative to the alignment axis of from 5&#xb0; to 30&#xb0;. The yarn has tensile strength of at least 280 MPa. A nanofiber fabric that includes a first sheet of multiwalled nanotubes and a second sheet of multiwalled nanotubes on the first sheet of multiwalled nanotubes. The multiwalled nanotubes of the first sheet are aligned in a first direction. The multiwalled nanotubes of the second sheet are aligned in the first direction. The first sheet and the second sheet are aligned so that the multiwalled nanotubes of the first sheet and the second sheet are both aligned in the first direction.

Fabrication and application of nanofiber ribbons and sheets and twisted and non-twisted nanofiber yarns

A process of producing a yarn, ribbon or sheet that includes nanofibers in which the process includes forming a yarn, ribbon or sheet comprising nanofibers, and applying an enhancing agent comprising a polymer to the yarn, ribbon or sheet.

Fabricating a nanofiber sheet, ribbon, or yarn by a continuous process that includes synthesizing a nanofiber forest in a forest growth region on a substrate, wherein the nanofiber forest comprises a parallel array of nanofibers, and further includes drawing said nanofibers from the nanofiber forest to form a primary assembly that is a sheet, ribbon or yarn. The substrate continuously moves from the furnace growth region into a region where the nanofibers in the forest are drawn.

The present invention is directed to nanofiber yarns, ribbons, and sheets; to methods of making said yarns, ribbons, and sheets; and to applications of said yarns, ribbons, and sheets. In some embodiments, the nanotube yarns, ribbons, and sheets comprise carbon nanotubes. Particularly, such carbon nanotube yarns of the present invention provide unique properties and property combinations such as extreme toughness, resistance to failure at knots, high electrical and thermal conductivities, high absorption of energy that occurs reversibly, up to 13% strain-to-failure compared with the few percent strain-to-failure of other fibers with similar toughness, very high resistance to creep, retention of strength even when heated in air at 450&#xb0; C. for one hour, and very high radiation and UV resistance, even when irradiated in air. Furthermore these nanotube yarns can be spun as one micron diameter yarns and plied at will to make two-fold, four-fold, and higher fold yarns. Additional embodiments provide for the spinning of nanofiber sheets having arbitrarily large widths. In still additional embodiments, the present invention is directed to applications and devices that utilize and/or comprise the nanofiber yarns, ribbons, and sheets of the present invention.

A nanofiber forest on a substrate can be patterned to produce a patterned assembly of nanofibers that can be drawn to form nanofiber sheets, ribbons, or yarns.

A process of producing a yarn, ribbon or sheet comprising nanofibers that includes infiltrating a liquid into the yarn, ribbon or sheet and evaporating the liquid from the yarn, ribbon, or sheet to strengthen the yarn, ribbon or sheet. The yarn, ribbon, or sheet can be formed by solid-state draw from a carbon nanotube forest.

A device including an array of aligned conductive channels. The conductive channels are operable for directional transport of species selected from the group consisting of electrons, ions, phonons, and combinations thereof. The conductive channels are provided for by nanofibers in a form selected from the group consisting of ribbons, sheets, yarns, and combinations thereof.

Fabricating a nanofiber ribbon or sheet with a process that includes providing a primary assembly by arranging carbon nanotube nanofibers in aligned arrays, the arrays having a degree of inter-fiber connectivity, drawing the carbon nanotube nanofibers from the primary assembly into a sheet or ribbon, and depositing the sheet or ribbon on a substrate.

Fabrication of nanofiber ribbons and sheets

Nanofiber ribbons and sheets and fabrication and application thereof

The present invention provides a method and apparatus for transferring an array of oriented carbon nanotubes from a first surface to a second surface by providing the array of oriented carbon nanotubes on the first surface within a vacuum chamber, providing the second surface within the vacuum chamber separate from the first surface, and applying an electric potential between the first surface and the second surface such that the array of oriented carbon nanotubes are sublimed from the first surface and re-deposited on the second surface.

Growing community of inventors

Dallas, TX, United States of America

Sergey Li