Controlled synthesis of monodisperse silica particles

Abstract

Spherical silica particles with uniform size (90-520 nm) were successfully fabricated using Stöber method. The size of silica particle (fabricated from ethanol, water, ammonia and tetraethyl orthosilicate) was examined by field-emission scanning electron microscopy. The effect of stirring rates (0-1200 rpm), reaction temperatures (12-75°C) and total volumes (80-400 0ml) on silica particle size was studied in detail. The experiment results indicate that stirring rates has no significant impact on the average size of silica particles, while higher temperature and larger total volume of reactant both result in smaller silica particles.

Systematic preparation of high‐quality colloidal silica particles by sol–gel synthesis using reagents at low temperature

“…6,13 In any case, the monodispersity of the silica particles prepared according to our LIT-synthesis method is quite high if one compares the standard deviation SD (included in Table 1) with previous works in the literature as discussed in Introduction. [10][11][12]…”

“…5 After the peak maximum, the reaction temperature decreases at about 15°C within 30 min, and this behavior can be related to the fact that during the growth process the production of hydrolyzed TEOS monomers is rate-limiting. 10,11 Thus, as the TEOS concentration niobyl(3+) cation (NbO 3+ ), which enters deformed polyhedra (octahedra, tetragonal pyramids) with a coordinationcovalent bond to oxygen. 16…”

“…However, to our knowledge, the low-temperature range has been little explored so far. [10][11][12] Indeed, in the abovementioned review, 6 the authors briefly referred to just one study concerning the effect of temperature on the Stobër synthesis. 12 In their study, Tan et al performed the synthesis reaction over a wide range of temperatures: 60, 40, 20, 0, and −20°C, reporting that the size of the silica particles varied inversely with the temperature and the smaller particles were even more monodisperse and spherical.…”

“…11 Finally, Liang et al performed experiments at reaction temperatures ranging from 12 to 75°C, confirming that higher temperatures result in a decrease in particle size. 10 The lowest temperatures used were 12 and 18°C, leading to average sizes of 521 nm (SD = 27 nm) and 481 nm (SD = 26 nm), respectively. 10 For this present work, the modified Stöber method that we propose is to keep, previously to the synthesis reaction, the initial temperature of the reagents at low values (exploring in this case the 6−14°C range) while fixing the other parameters, such as laboratory temperature (RT), humidity and reagent concentrations.…”

“…10 The lowest temperatures used were 12 and 18°C, leading to average sizes of 521 nm (SD = 27 nm) and 481 nm (SD = 26 nm), respectively. 10 For this present work, the modified Stöber method that we propose is to keep, previously to the synthesis reaction, the initial temperature of the reagents at low values (exploring in this case the 6−14°C range) while fixing the other parameters, such as laboratory temperature (RT), humidity and reagent concentrations. On the other hand, in comparison to previous works, the novelty of our approach is thus twofold.…”