Abstract: (8405 Views)
We report a simple and practical approach for the easy production of superhydrophobic coatings based on TiO2-SiO2@PDMS. In this study, we used tetraethylorthosilicate (TEOS) and titanium tetraisopropoxide (TTIP) as a precursor for the sol-gel synthesis of SiO2 and TiO2, respectively. Afterward, the surface of nanoparticles was modified by 1,1,1,3,3,3-hexamethyldisilazane (HMDS) before being combined with polydimethylsiloxane (PDMS). The hydrophobic property of coatings was evaluated by static contact angle measurements. The phase composition and structural evolution of the coatings were examined by X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR) analysis. It was shown that changing the weight ratio of the solution composition of the coating can affect the hydrophobicity of the surface. The best sample has shown a superhydrophobic property with a 153˚ contact angle which contained (75%TiO2-25%SiO2) and PDMS at a weight ratio of 1:1. Moreover, the results showed that the superhydrophobic coating retains its hydrophobic properties up to a temperature of 450 ˚C, and at higher temperatures, it converts to a super hydrophilic with a water contact angle close to 0 ˚. The SiO2-TiO2@PDMS coating degrades methylene blue by about 55% and was shown to be capable of photocatalytically decomposing organic pollutants.
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Highlights
- Silica and titania nanoparticles were successfully produced by the sol-gel method
- The coating of SiO2-TiO2@PDMS on glass increased its contact angle from 30° to 152°
- The best powder composition to produce a superhydrophobic coating in this method was 75% titania and 25% silica, which provides the highest contact angle
Increasing the amount of powder as well as increasing the concentration of PDMS in the coating solution reduces the contact