Green Synthesis of Silica- Polysaccharides Nano- composites from Sodium Silicate and Aloe Vera gel for Self-cleaning of Solar Mirrors

Abstract

Synthesis of silica-Nano-composites from both sodium silicate and Aloe Vera gel via low-cost sol-gel silica nanoparticles (Si NPs) was investigated to be used as self-cleaning for solar mirrors. The produced materials were analyzed by (EDX) which indicates the existence of a high content of silicon in the Nano-silica composites. FTIR was utilized to obtain the structure characterization of our samples, whereas the poly-siloxane groups already formed and found the backbone of Si-O-Si. X-ray diffraction (XRD) was also utilized to identify the silica structure, whereas a broad peak and an amorphous phase were obviously created. The images of Nano-silica content embedded in polymer with different magnifications were obtained using (SEM). The surface roughness of the Nano-silica composites was attained using the Atomic Force microscope (AFM). The hydrophobicity of the solar mirrors surface was investigated using the contact angle measurement and zeta potential measurement. The results obtained by both Thermo-gravimetric analysis and data thermal analysis (TGA & DTA) illustrated that the Nano-silica composite with 40 ml of Aloe Vera gel is more stable than that obtained of Nano silica composites with 20 ml and 60 ml of Aloe Vera gel. The reflectance of solar mirrors after using Nano-silica composite assures high efficiency.