Synthesis of Silicon Dioxide (SiO) Nanowires via a Polyethylene Glycol-Based Emulsion Template Method in Isopropanol.

Typical wet-chemical methods for the preparation of silica nanowires use polyvinylpyrrolidone and n-pentanol. This study presents a polyethylene glycol-based emulsion template method for the synthesis of SiO nanowires (SiONWs) in isopropanol. By systematically optimizing key parameters (type of solvent, polyethylene glycol molecular weight and dosage, dosage of sodium citrate, ammonium and tetraethyl orthosilicate, incubation temperature and time), SiONWs with diameters about 530 nm were obtained. Replacing polyvinylpyrrolidone with polyethylene glycol enabled anisotropic growth in isopropanol, overcoming the dependency on traditional solvents like n-pentanol. Scale-up experiments (10× volume) demonstrated robust reproducibility, yielding nanowires with consistent morphology (~580 nm diameter). After calcination at 500 °C for 1 h, the morphology of the nanowires did not change significantly.