Light absorption and hydrophobicity of a polystyrene/multiwall carbon nanotube composite with surface nanostructures

This paper describes an investigation into how combined carbon nanotube doping and surface nanostructuring affects the surface properties of polystyrene. Multiwall carbon nanotubes (MWCNTs) have unique anisotropic electrical properties that can be utilized for light absorption, electromagnetic shielding and nanoscale electostatic forces. Polystyrene was doped with 5 wt% MWCNTs and the resulting composite was wetted onto a porous anodic alumina template to form a nanostructure surface of nanotubes. Scanning electron microscopy revealed a hierarchical surface structure with the composite nanotubes bundled together as the MWCNTs increased the attractive forces between the composite nanotubes. Water droplet testing revealed that this hierarchical surface structure was superhydrophobic. Though the presence of the MWCNTs caused a direct increase in absorption, the hierarchical surface structure increased reflection. The addition of 5 wt% of the anionic surfactant Sodium Dodecyl Benzene Sulfonate to ensure MWCNT dispersal did not significantly change hydrophobicity or light absorption despite the hierarchical surface structure becoming finer. The created composite has potential use as a surface layer on an organic surface cell as it provides reduced cleaning needs and electrical disturbance but further work is required to reduce the reflection.