Fabrication of Superstrong Ultrathin Free-Standing Single-Walled Carbon Nanotube Films via a Wet Process

A one‐pot and readily practical approach is described for the preparation of superstrong, ultrathin, free‐standing single‐walled carbon nanotube (SWNT) films. The SWNT films, with controlled thicknesses of tens to hundreds of nanometers, are prepared from commonly commercialized SWNTs via a wet process. The SWNTs could be easily transferred onto any substrates after self‐releasing from filter membranes without further treatment. The obtained films exhibit excellent performances with sheet resistance of 223 Ω sq−1 and a transparency of 90% at 550 nm was obtained. Most important is that the as‐prepared free‐standing SWNT ultrathin films showed extremely high tensile strength up to 850 MPa for only about a 20‐nm thick film, which has great significance for practical applications, for example, as flexible electrode materials. The SWNT film is used to construct a capacitive touch‐screen prototype, which has a highly sensitive and quick signal touch response. Superstrong, transparent, and conductive free‐standing single‐walled carbon nanotube (SWNT) ultrathin films are fabricated via vacuum filtration. The films exhibit great potential for use in flexible capacitive touch screens.