Fluoropolymers have experienced widespread use as functional materials in applications ranging from water purification to energy storage. Production of large area, two-dimensional (2D), ultra-thin, semifluorinated polymer films is expected to have significant impacts on multiple fields. Some of these fields are organic electronics and optoelectronics where substantial challenges have yet to be overcome. One key challenge in making functional 2D polymer films is that the polymer film formation reaction still occurs in traditional bulk solutions.
USD researchers have discovered a new procedure for synthesizing 2D, ultra-thin, semifluorinated polymer films at a liquid-liquid interface – for example, the interface between a hydrocarbon solvent (e.g. DMSO) and a fluorocarbon solvent (e.g. HFE-7200). By using monomers and precursors that are only soluble in one of the solvents, a 2D ultra-thin film was formed at the liquid-liquid interface. The film formed using this method is around six nanometers thick. The thickness of the membrane formed can be varied by increasing or decreasing the reaction time. Permeability and exposure tests have demonstrated that the film is both mechanically strong and thermally stable. This method can be expanded into many different semifluoropolymer syntheses as long as their corresponding monomers are only soluble in orthogonal solvents.