Eco-Friendly Fabrication of Highly Stable Silica Aerogel Microspheres with Core–Shell Structure

Abstract

Silica aerogel microspheres show great potential in various fields as fillings in different materials. It is important to diversify and optimize the fabrication methodology for silica aerogel microspheres (SAMS). This paper presents an eco-friendly synthetic technique for producing functional silica aerogel microspheres with a core–shell structure. Mixing silica sol with commercial silicone oil containing olefin polydimethylsiloxane (PDMS) resulted in a homogeneous emulsion with silica sol droplets dispersed in the oil. After gelation, the droplets were transformed into silica hydrogel or alcogel microspheres and coated with the polymerization of the olefin groups. Microspheres with silica aerogel as their core and polydimethylsiloxane as their shell were obtained after separation and drying. The sphere size distribution was regulated by controlling the emulsion process. The surface hydrophobicity was enhanced by grafting methyl groups onto the shell. The obtained silica aerogel microspheres have low thermal conductivity, high hydrophobicity, and excellent stability. The synthetic technique reported here is expected to be beneficial for the development of highly robust silica aerogel material.

Facile Synthesis of Polymer-Reinforced Silica Aerogel Microspheres as Robust, Hydrophobic and Recyclable Sorbents for Oil Removal from Water

“…Additionally, the apparent density gradually increases with the increasing crosslinking time from 3 to 24 h, revealing more polymer species loaded onto the framework of the aerogel skeleton. Thus, RSAM samples crosslinking for 24 h exhibited the maximum density and the denser appearance, especially the R-V-24 sample, the density (0.21 g/cm 3 ) of which was much higher than that of traditional silica and silica-based aerogels (~0.1 g/cm 3 ) [28][29][30]. The digital photos of the PSAMs, ASAMs and RSAMs in water, obtained via different drying methods under different crosslinking times, are vividly shown in Figure 2.…”

Preparation and property of PVA-based colorful coating composite reinforced with silica aerogel particles filled by high-loaded flame retardant

“…On the negative side, violent physical processing can damage the original cavity construction, with no guarantee of its microdimension and uniformity as the ller. Therefore, the straightforward approach was to prepare aerogel in the form of microparticles [22][23][24][25][26][27], on the basis of emulsion system between sol-gel precursors and soft templates including organic solvent, partially reserving as the ller [28,29]. Besides, microencapsulation technology has been constantly improved, modi ed and adapted for miscellaneous purposes and usages.…”