Creating supersolvophobic nanocomposite materials

Abstract

This paper illustrates two techniques that enhance the supersolvophobicity of inherently hydrophilic polymeric thin films. The first technique involves creating a perfluoro-functionalized carbon nanotube based “ink” that can be sprayed on virtually any surface, including polymeric thin films, to greatly enhance the supersolvophobicity. Our results show contact angles greater than 150° with 30 wt% monoethanolamine (MEA) on polysulfone (PSF) and polyimide films that have been treated with the CNT-based ink. The second method involves synthesizing a homogeneous, composite solution consisting of polymer (both PSF & polyimide) and perfluoro-functionalized CNTs (fCNTs). By designing a methodology for the fabrication of fCNT–polymer composite solutions, the supersolvophobicity is not only limited to the surface, but is present within the composite, thereby extending the proposed technique to a range of geometries and length scales. The ratio of polymer : fCNT was varied to locate an upper limit at which films maintain supersolvophobicity. The low density of fCNTs makes them a better alternative to conventional fluorine-based polymeric filler materials (i.e. PTFE, PVDF).