Robust, amphiphobic and super-buoyant CNT foams promising for self-floating functional platforms

Light-weight materials have been holding great potentials and practical usages in floating functional platforms, while it remains in great needs in developing novel ultra-light foam materials towards future applications. Herein, we demonstrated the fabrication and self-floating application of an ultra-lightweight, robust and amphiphobic carbon nanotube (CNT) foams. The foams were prepared by a facile, fast and scalable CVD process, where alcohol vapor was used as carbon source at 1100 °C to weld the CNTs together in the original CNT aerogels and the reaction time was greatly reduced from hours to 30 min, several times faster than reported results. The compressive strength of foams was remarkably enhanced by 250 times and the contact angle to water increase from ∼100° to 132°. Further vapor modification by 1H, 1H, 2H, 2H-perfluorodecyltrichlorosilane (FDTS) enabled the foams both super-hydrophobic (162° to water) and oleophobic (138° to oil), which also show excellent long-term stability in strong acid and alkaline solutions. Most importantly, such robust and amphiphobic CNT foams exhibited superb self-floating performance in water and oil, which could bear more than 300 times its own weight, nearly 10 times higher than conventional polymer-based buoyant materials, such as EVA, PVC, PU, providing great promise for marine applications.