OICC Press Journal of Nanostructure in Chemistry 2193-8865 14 6 2023 01 12 Facile, fast, and green preparation of high-purity and quality silica nanoparticles using a handmade ball mill: comparison with the sol–gel method 10.1007/s40097-022-00522-0 EN Saeed Karimkhani Faculty of Chemistry, Islamic Azad University, Tehran, IR Pirouz Derakhshi Faculty of Chemistry, Islamic Azad University, Tehran, IR Parviz Aberoomand Azar Science and Research Branch, Department of Chemistry, Faculty of Science, Islamic Azad University, Tehran, IR Seyedeh Mahsa Sheikh-Al-Eslamian Dental Research Center, Research Institute of Dental Sciences, Shahid Beheshti University of Medical Sciences, Tehran, IR Journal Article 2023 01 12 Abstract In this study, silica nanoparticles (SiO 2 NPs) were fabricated using a handmade ball mill as a novel, simple, rapid, cost-effective, and green approach. The sol–gel method was also used to produce these NPs as a comparative method. The SiO 2 NPs produced by both methods were characterized using high-resolution transmission electron microscopy (HRTEM), dynamic light scattering (DLS), energy-dispersive X-ray analysis (EDX), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), X-ray fluorescence (XRF), and Brunauer–Emmett–Teller (BET). In the ball mill technique, different parameters, such as milling rotation speed (6–240 rpm), powder-to-ball ratio (1:5, 1:10, 1:20 kg), milling time (3–12 h), air blowing speed (7.5–30 km/h), and air suction speed (50, 100, and 200 m 3 /h), were optimized. The optimum conditions were found to be 240 rpm, 1:20 kg, 12 h, 7.5 km/h, and 50 m 3 /h for the rotating speed, powder-to-ball ratio, milling time, air blowing speed, and air sucking speed, respectively. Six steps were designed for the preparation of NPs in this ball mill, and the minimum particle size under the optimum conditions was obtained at 16.6 nm at step 6. The high purity of SiO 2 particles in large volumes with particle sizes from μm to nm was achieved. The produced NPs can be used in the cosmetics industries, dentistry, and other fields. Graphical abstract The cylindrical iron pipe was provided. Both sides of the cylindrical pipe were placed continuously to input and output the materials in the mill system. The rectangular iron table was made and the cylindrical iron pipe was assembled on the table. To rotate the planetary ball mill system, the electromotor was installed under the table, and to control the rotation speed, an inverter was installed. An adjustability air blower to adjust the inlet air pressure was installed. At the outlet of the mill, a separating tower was designed, which is connected to the separating tower from the mill outlet by fittings. The regulator dimmer was installed at the end of the tower, and the air suction device was installed to control the power and speed of air suction, which is equipped with a suction device. The surface of the inner iron walls of the cylinder was covered with cut silica stones. Before installing the inner walls and ball to the mill, the silica stones of the inner walls and the grinding ball were washed by HCL solution and then the deionized water.