Exceptionally robust and conductive superhydrophobic free-standing films of mesoporous carbon nanocapsule/polymer composite for multifunctional applications

A novel mesoporous carbon nanocapsule (MCC)/polyvinylidene fluoride (PVDF) polymer composite based free-standing film with multifunctional properties is fabricated by a facile solution approach that is appropriate for dip coating, brush-on and spray applications. The MCC/PVDF composite film exhibits superhydrophobic properties with a water contact angle of approximately 160° and a sliding angle of 5°. The films have a high thermal stability (up to 350 °C in oxidative atmosphere) and are also electrically conductive (tunable from ∼10−3 S m−1 to 10−2 S m−1). The superhydrophobicity is retained even in highly corrosive acidic and basic conditions (pH 1.29-13.54, concentrated HNO3 exposure and ammonium hydroxide solution), as well in a wide humidity range (35-83%). The mesoporous carbon containers (∼100 nm-1 μm size) also provide an interesting platform for encapsulating a variety of functional nanomaterials and activate release, thereby adding to the multi-functionality of the superhydrophobic conductive films of exceptional environmental stability, mechanical strength (∼0.1 GPa) and flexibility.