Hierarchical Structure of SiO₂ by In Situ Modification Combining Quartz Sand and Methyltrimethoxysilane

SiO₂ were successfully synthesized by sol–gel process via in-situ modification. The SiO₂ consists of two kinds of co-precursor namely raw material from quartz sand and methyltrimethoxysilane (MTMS) as main SiO₂ source. By introducing SiO₂ with different sizes of particle micro-submicron scale, it was suggested to construct hierarchical structure. The sample was characterized by X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM), and Atomic Force Microscope (AFM) to analyze crystal structure, morphology of particles, and surface roughness of the samples. In this research, SiO2 co-precursor from quartz sand were extraction and synthesis to be SiO₂ quartz (SQ) phase and SiO₂ amorphous (SA) phase respectively which is combine with SiO₂ based MTMS by sol–gel process via in-situ modification. Based on the results, it can be concluded that SiO2 with high purity levels maintains its crystal structure even after in-situ modification, resulting in an increase in particle size to approximately 12-20 μm. SEM images showed that particle was irregular shape due to agglomeration which is SiO2 based quartz sand stick by SiO₂ based MTMS. AFM showed the surface roughness of MTMS/SQ have a larger roughness than MTMS/SA with Sa 3.3 ± 0.8 nm and Sq 5.0 ± 1.0 nm. The formation of hierarchical structure layers based on SiO₂ has a promising potential for wide applications in various fields such as hydrophobic surface.