Thermo-responsive surface wettability on a pristine carbon nanotube film

A superhydrophobic carbon nanotube (CNT) film is fabricated by a simple spray-coating method without any chemical modification. The superhydrophobic surface changes after heating to a state of superhydrophilic wettability, and such transition may be attributed to the change of electronic structures of CNTs since the surface structure and composition after treated remain the same as the pristine CNTs. The initial wettability state is reestablished within 24 h of storage in air, and the time can be shortened to only 1 min when the heated CNT film was stored in deionized water.

Reversible switching between superhydrophobicity and superhydrophilicity obtained by alternating heating and air storage was observed on the pristine CNT film. This reversible surface wettability may be attributed to the change of surface charges of CNTs.Figure optionsDownload as PowerPoint slideResearch highlights
► Simple method to fabricate a superhydrophobic carbon nanotube film.
► Reversible wettability switching by alternating heating and air storage was observed.
► The reversible wettability may be attributed to the change of surface charges.
► Potential applications in areas requiring multifunctional CNT-based films.