Available online at www.sciencedirect.com ScienceDirect Materials Today: Proceedings 22 (2020) 1669–1675 www.materialstoday.com/proceedings 2214-7853 © 2019 Elsevier Ltd. All rights reserved. Peer-review under responsibility of the scientific committee of the 2nd International Conference on Materials Manufacturing and Modelling, ICMMM – 2019. ICMMM 2019 Process parameter effects on particle size reduction of sol-gel synthesized silica nanoparticles Tankeshwar Prasad a* , Sudipta Halder a , S. S. Dhar b a Department of Mechanical Engineering, National Institute of Technology Silchar, Silchar-788010, Assam, India b Department of Chemistry, National Institute of Technology Silchar, Silchar, Assam, 788010, India Abstract In present study, SiO 2 nanoparticle was prepared using sol-gel method. Tetraethyl orthosilicate (TEOS) was chosen as a silica precursor, ethanol as a solvent, water as co-solvent and ammonia as a catalyst. The effects of most influencing process parameters molar ratio (0.5, 1 and 2) of tetra-(ethyl)-orthosilicate (TEOS) to ammonia (NH 3 ) with respect to particle size variation was investigated experimentally in detail. The size of SiO 2 particles was controlled by tuning the NH 3 concentration with respect to TEOS. Scanning electron microcopy (SEM) studies were performed for understanding the size of SiO 2 nanoparticles while surface functional groups was determine by Fourier transform infrared (FTIR). The amorphous phase and purity of particles was identified by X-ray diffraction (X-RD) and energy dispersive spectroscopy (EDS) respectively. This work demonstrates the molar ratio variation had the noticeable effect on particle size reduction of SiO 2 particles. it was found that the particle size decreases with increases of NH 3 concentration with respect to TEOS (molar ratio = 1) and found lowest particle size of 40 nm (TEOS: NH 3 ) with fixed amount of TEOS, ethanol, water and reaction time. © 2019 Elsevier Ltd. All rights reserved. Peer-review under responsibility of the scientific committee of the 2nd International Conference on Materials Manufacturing and Modelling, ICMMM – 2019. Keywords: silica particles, sol-gel method, ammonia concentration, SEM, particle size; 1. Introduction With increasing demand of nanomaterials, SiO 2 is the most important ceramic material which is extensively used in chemical and advance polymer industries owing nanosized of particle with large surface area [1]. The quality of these particles is mostly dependent on the geometrical shape, size and surface chemistry of SiO 2 particles [2]. * Tankeshwar Prasad. Tel.: +91-9126693169; fax: +91-384222479. E-mail address: tankeshwarprasadg@gmail.com