Multifactorial Investigation of Silica Nanoparticle Synthesis through Ultrasonic Spray Pyrolysis for Controlled Morphology and Diameter

This research delves into the comprehensive exploration of silica nanoparticles (SiO2-NPs) synthesis via ultrasonic spray pyrolysis. Essential factors investigated encompassed varying concentrations of tetraethyl orthosilicate (TEOS) (0.51 M, 0.25 M, and 0.12 M), furnacetemperatures (200°C, 300°C, and 400°C), carrier gases (Ar, N2, O2), residence times of reactants in the furnace (0.5 sec, 1.5 sec, 5 sec), and solvents (acetone, ethyl acetate, andethanol). The influence of incorporating F127 in the synthesis process was scrutinized for itsrole in producing mesoporous silica nanoparticles. Results indicated that an escalation in TEOS concentration from 0.12M to 0.51M at 400°C resulted in a proportional increase in the average particle diameter of SiO2 nanoparticles from 7 nm to 40 nm and the specific surface area decreased from 147 to 97 m²/g, revealing a narrow size distribution. Manipulating the nitrogen flow rate during the furnace process from 100 to 300 ml/min exhibited the capability to yield SiO2 nanoparticles by increasing their particle size to 61nm. Additionally, an extension of the residence time of precursors, achieved through careful regulation of the carrier gas flow rate,yielded a noticeable augmentation in the average particle diameter. Notably, the choice of solvent emerged as a discernible factor, leading to the fabrication of SiO2-NPs with various morphologies. This multifaceted investigation provides valuable insights into the intricacies of silica nanoparticle synthesis, contributing to the understanding of the nuanced interplay of parameters in achieving desired particle characteristics for diverse applications in nanotechnology and materials science.