Boron Doped Carbon Nanowalls as Multifunctional Interfaces for Directional Water Transport and Electrowetting

Abstract

Wettability on demand by regulating the surface characteristics of sp² and sp³ hybrid nanocarbons has significantly advanced. In this regard, single step synthesis of boron doped carbon nanowalls is reported via microwave plasma enhanced chemical vapor deposition as multifunctional surfaces for controlled water transport and polarity dependent electrowetting. Boron doped carbon nanowall surface (BCNW) surfaces exhibited rapid transition from highly hydrophobic to superhydrophilic at very small DC bias of 1.2 V. In addition, water transport via electrowetting in a sandwiched droplet structure from one boron-doped carbon nanowall surface (BCNW) surface to another is successfully achieved at low external bias. The application of an electric field allows for dynamic modulation of the droplet's contact angle, facilitating fine control over its deformation and motion. The unique structural, morphological and roughness effects can account for regulated wettability and rapid transitions. This approach of synthesizing nanostructured surface with hydrophobic nature and polarity dependent electrowetting can be used in numerous applications like biomedical devices, microfluidics, supercapacitors and electrochemical transport of liquids through membranes.

Keywords: boron‐doped nanocarbons; chemical vapour deposition (CVD) grown nanostructures; electrochemistry; electrowetting; surface modification.