Separation of Spherical Nanosilica from Agricultural Wastes in Vietnam via Ultrasonic-Assisted Precipitation and Application for Effective Removal of Methylene Blue from Aqueous Solution

Figure 3

The morphology of BA-SiO₂ nanomaterial with different volume ratios of NH₄OH : ethanol: (a) 0 : 0; (b) 0 : 15; (c) 3 : 12; (d) 6 : 9; (e) 9 : 6; (f) 12 : 3; (g) 15 : 0.