Figure 2D shows the variation of water contact angle with the size of the fluorinated silica nanoparticles in the thin films. Figure 2D shows that the water contact angles of the films prepared with the fluorinated silica nanoparticles of sizes 40 (22 and 69 ( 21 nm are found to be 122 ( 3 and 129 ( 3 , respectively. These values are slightly higher than the contact angle value of 108 obtained on FAS17 passivated flat glass surface.
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The slight increase, although not great, in the contact angle values can be attributed to the presence of low surface energy fluorinated species arising from the functionalization of the silica nanoparticles. We have observed that the water contact(