Tailored size control of silica nanoparticles for drug delivery: A systematic study of synthesis parameters

Controlling the size of silica nanoparticles (SiNPs) is crucial for optimizing their efficacy in drug delivery applications. This study presents a micelle entrapment method utilizing triethoxyvinylsilane (TEVS) as a silica precursor, butanol as a solvent, Tween 80 as an anionic surfactant, and aqueous ammonia as a catalyst to finely control SiNP sizes. Systematic investigations into reaction temperature, butanol volume, and TEVS volume enabled precise nanoparticle sizing from 15 nm to 1800 nm. Specifically, raising the temperature from 22°C to 47°C and increasing butanol from 2 mL to 10 mL resulted in size increments ranging from 27 nm to 172 nm and 15 nm to 1800 nm, respectively. TEM analysis showed that increasing TEVS volume (1 mL to 4 mL) produced bimodal particle distributions with consistent particle sizes. Spherical morphology was confirmed via TEM and Malvern Zetasizer Nano ZS measurements. Predictive equations correlating synthesis parameters and nanoparticle sizes were established, providing a practical tool to achieve targeted SiNP sizes without additional experimentation.