Synthesis of silica particles through conventional sol-gel and sonochemistry methods and the effect of catalyst, water concentration and sample environment to the particle size

Abstract

Various methods have been carried out in an effort to obtain SiO2 (Silica) particles with relatively the same grain size distribution and a uniform shape. This fine Silica particle size will be useful in the formation of SiC in the next stage. In this works, Silica particles has been synthesized through two different methods: conventional sol-gel and sonochemistry (using ultrasonic probe). Silica was synthesized by mixing TEOS, ethanol, ammonia, and D.I water with the molar ratio of 1 : 75.9 : x : y respectively. In sol-gel method, x was varied with 2.85, 5.7, and 8.54 M while y was fixed at 61.6 M. In sonochemistry method, y was varied with 6.69, 12.3, and 75.9M while x was fixed at 2.85 M Additional variation of sample environment including with and without ice has also been done in sonochemistry method. Amorphous phase was found in all samples from the XRD profiles. FT-IR results showed that the IR spectral peaks of all samples match the FT-IR spectrum of SiO2 with symmetric and asymmetric stretching mode of Si-O functional groups at 802 – 810 cm−1 and 1093 – 1103 cm−1 wavenumber. SEM images indicated that the average of SiO2 particle size tends to increase with the higher amount of ammonia concentration used and lesser concentration of water used results in smaller particle size. The influence of sample environment in sonochemistry method showed an interesting phenomenon where a lot of small particles sticked with bigger particles.

Medium-high frequency sonication dominates spherical-SiO2 nanoparticle size

“…The same phenomenon was observed during 20 kHz sonication with an ultrasonic horn at 40 W for 60 min. It is speculated that the NH 4 OH/TEOS molar ratio (0.84) used in the above Stöber mixtures was lower as compared with those (NH 4 OH/TEOS molar ratio: 2.33–30.00) reported in previous studies [24] , [25] , [26] , [27] . In contrast, SSNs were produced under the 40 kHz sonication at 97 W for 20 min in a ultrasonic bath, but the preparation reproducibility was poor.…”

“…615 nm silica particles were obtained by 25 kHz sonication at 160 W for 5 min and stirred at 999 rpm simultaneously. In 2022, Kamila et al found that the larger silica particles are generated by sonochemical method as compared with the sol–gel Stöber method again [26] . In the preparation, the Stöber mixture containing 2.85 mol/L ammonia and 1 mol/L TEOS (NH 4 OH/TEOS molar ratio: 2.85) with ethanol and water was stirred at 450 rpm for 90 min at room temperature, or sonicated with an ultrasonic probe for 30 min (5 s pulse on and 2 s pulse off).…”

The Evolution of Sonochemistry: From the Beginnings to Novel Applications

“…In this context, Kamila et al. (2022) synthesized silica particles by conventional sol‐gel and sonochemistry, where the USI modified the size and increased the reaction time, producing a smaller particle size [133] . Dimas et al.…”

“…[132] In this context, Kamila et al ( 2022) synthesized silica particles by conventional sol-gel and sonochemistry, where the USI modified the size and increased the reaction time, producing a smaller particle size. [133] Dimas et al(2020) obtained TiO 2 -anatase NPs with a size of 5.2 nm and a mesoporous structure. [134] Jung et al ( 2020) developed a nano-cubic composite of carbon, iron oxide, and gold (C-Fe 2 O 3 @Au) sonochemically, obtaining a NPs size of 43 nm.…”

Characteristic investigations on bio-silica gel prepared from teff (Eragrostis tef) straw: effect of calcination time

“…In this context, for bio-based silica (biosilica) production, different methods have been used up by exploiting the various agricultural leftovers as a feedstock. Among them, the hydrothermal technique [25], sol-gel processing [26], plasma and combustion method [27], and chemical vapor deposition (CVD) [28] are the most extensive techniques. In this application, silica is most commonly produced commercially via the CVD process [1].…”