Effect of heat treatment on the surface morphology and hydrophobic of TEOS-MTES-Al2O3-CTAB nanocomposite films

Abstract

The TEOS-MTES-Al2O3-CTAB hydrophobic hard nano-composite films were prepared using tetraethoxysliane (TEOS) and aluminium isopropoxide Al(C3H7O)3 as precursors, keeping the molar ratio of TEOS, ethanol (EtOH), deionized water, dilute HCl and methyltriethoxysilane (MTES) at 1:3.8:1:5×10-5:0.8, and added AlOOH sol into TEOS-MTES sol, the Si/Al molar ratio (M) was 1:0.06. The last step, finally 1.5wt % cetyltrimethylammonium bromide (CTAB) was added in the nano-composite sol. The films were heated to different temperatures in the range 250°C~450°C for 2h. The prepared films were characterized by Atomic Force Microscopy (AFM), water contact angle measurements and QHQ pencil hardness tester. The results showed the surface roughness of the films ranging from 9.598 to 34.297 nm. The water contact angle as high as 120° and the hardness as high as 6H.