Hierarchical Structure of SiO₂ by <i>In Situ</i> Modification Combining Quartz Sand and Methyltrimethoxysilane

Abstract

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.