Fluoroalkyl-Modified Polysilazanes for Omniphobic Coatings

Organic polysilazanes belong to a family of organosilicone polymers containing Si-N linkages. These materials have been used for hydrophobic coatings but fluoroalkyl chains are required for oleophobic surfaces. We herein suggest that fluoroalkyl-modified polysilazanes to provide omniphobic nature to solid surfaces. First CF3(CF2)7CH2CH2SiCH3Cl2 was synthesized with 1H,1H,2H-perfluoro-1-decene and Me2SiCl2 by hydrosilylation in the presence of Karstedt catalyst. CF3(CH2)2SiMeCl2, CF3(CF2)7CH2CH2SiMeCl2 or CF3(CF2)7CH2CH2SiMeCl2 was reacted with MeSiHCl2 in the presence of NH3 and pyridine by co-ammonolysis. Final products were examined by 1H-NMR, FT-IR and TGA. Water and oil (hexadecane) contact angles were measured with dip-coated samples on glass slides. The best omniphobic sample is the copolymer between CF3(CF2)7CH2CH2SiMeCl2 and MeSiHCl2 (7:3 weight ratio). The coated glass exhibited 110 degree and 48 degree of water and oil contact angles, respectively.