Investigation of the Effect of DMOAP with Dimethyl Octadecyl Aminopropyl Group on TMOS Wettability Properties

In this study, organic-mineral hybrid silica coating was prepared by sol-gel process, in order to investigate the effect of Dimethyl octadecyl amin propyl group on TMOS wettability. The sol solutions were prepared at room temperature by hydrolysis and condensation of tetra methoxysilane (TMOS) diluted in methanol as solvent and in the presence of acetic acid as a catalyst and dimethylacetaldehyde (3- (trimetoxylsilyl) propyl) ammonium chloride (DMOAP) as a surface modifying. The glass substrates were dipped vertically in the transparent silica sol and withdrawn with the speed of 5 mm/s. The DMOAP / TMOS molar ratio was varied in the range from 0 to 2 to investigate the effect of Dimethyl octadecyl amin propyl group. In these conditions, TMOS: MeOH: H2O: CH3COOH molar ratio was fixed at 1: 15: 4: 2, respectively. The morphology of the prepared layers and surface chemical modification of the TMOS were carried out by field emission scanning electron microscopy (FE-SEM), atomic force microscopy (AFM), Fourier transform infrared spectrometer (FT-IR) and simulated thermal analysis (STA), respectively. The study of physical properties was performed by measuring the contact angle of a drop of water (CA) and UV-Vis spectroscopy. The results showed that with the increase of DMOAP, the TMOS wettability increased, which probably related to the optimal availability of active sites at the silica coating surface.