ساخت و ارزيابي ريزساختاري و خواص اپتيكي لايه‌هاي نازك نانوكامپوزيتي ابرآبگريز بر پايه سيلوكسان

Fabrication and eva‎luation of Microstructural and Optical Properties of Super-Hydrophobic Siloxsane-Based Nanocomposite Thin Films

نانو فناوري

High transparency is one of the basic requirements for the good performance of optical devices such as smart windows, solar panels and optoelectronic devices. Also, the repeated placement of these devices in different outdoor environments inevitably stains their outer surface, which reduces their performance. The purpose of this research is to make transparent superhydrophobic coatings to increase the efficiency of optical devices and improve their performance.In this research, first, silica nanoparticles were synthesized by mixing tetraethylorthosilicate with deionized water and ethanol in different amounts. Also, commercial nanoparticles were first dispersed in water and ethanol mixture and then modified with hydrophobic agents such as PDMS or HMDS. In order to eva‎luate the size and distribution of nanoparticles, the Dynamic light scattering (DLS) test and to eva‎luate the stability of nanoparticles, the Zeta potential test was used.To make nanocomposite thin films, silica nanoparticles were combined with polyvinyl alcohol (PVA) polymers, solvent-based resin, water-based resin, and GPTMS separately.The method of applying the coating was layer by layer or mixed in nanoparticles sol. Then the coatings were immersed in hydrophobic polydimethylsiloxane, hexamethyldisilazane and trimethylchlorosilane solutions separately.to eva‎luate the physical and chemical properties of the coatings, scanning electron microscope (SEM), Fourier transform infrared (FTIR) measurement, static contact angle and water sliding contact angle, adhesion test and UV stability test were used.The results showed that the silica nanoparticles synthesized with TEOS precursor have a size of 216 nm and a zeta potential of -19.1 mV and after adding the APTES agent,By creating the stricy factor, the size of the nanoparticle reached 29 nm and the zeta potential reached -0.3 mV. The contact angle in polymer coatings made with silica nanoparticles on two-component solvent base resin and PVA reached more than 150° and the sliding angle reached 3°.The transparency of PVA/TEOS composites in the range of visible light was about 80%, and according to the adhesion test, the coatings had good adhesion to the surface.With continuous exposure to UV rays, the water drop angle decreased by 5% in TMCS hydrophobic coatings, which maintained its superhydrophobicity in this case, and finally decreased by 30% in the rest of the coatings.

5

31449