Above 170° water contact angle and oleophobicity of fluorinated graphene oxide based transparent polymeric films

Understanding and tuning the wettability of the surfaces are highly intriguing for various applications. The development of stable and transparent coatings over aluminium alloys and glass substrates for making them superhydrophobic and extended oleophobic (lower to the surface tension of 33.4 mN/m (coconut oil)) using a scalable and simple spray painting technique is demonstrated. Fluorinated graphene oxide (FGO, fluorine content of 34.4 atomic weight %), an atomically layered material, modified Polydimethylsiloxane (PDMS) polymer composite is used as the paint for the coatings. The coated films were studied for their surface and compositional features. A water contact angle (CA) of 173.7° (close to the highest ever reported water CA, 175°) is achieved with 60 wt% FGO in PDMS, and the same showing a CA of 94.9° with coconut oil, in conjunction with a low contact angle hysteresis (4°). The work of adhesion with the amount of FGO is studied and the surface energy of FGO containing paints is calculated and compared with the bare paints using Zisman plot analysis.