Results and discussion
Preparation of the PFPE-NS
In this work, we prepared the superhydrophobic coating material by a simple procedure as shown in Scheme 1. Firstly, the amino functionalized silica nanoparticles were prepared according to the Sto¨ber method. The size distribution by number of the amino functionalized silica particles is shown in Fig. 1. It indicated that more than 70% of particles are less than 100 nm in diameter. Then themodification of the silica nanoparticles by PFPE chains was conducted by the reaction of AF-PFPE and amino functionalized silica particles in Freon 113 using triethylamine as catalyst. PFPE-NS (1) and (2), with different surface morphology, were obtained by controlling the reaction time of modification as 2 and 12 h, respectively.