Effects of silica aerogel particle sizes on the thermal–mechanical properties of silica aerogel – unsaturated polyester composites

Abstract

Silica aerogels with a surface area as high as 773 m 2 g −1 and a density of 0.077 g cm −3 were produced from rice husk via sol-gel process and ambient pressure drying. A particulate composite material was prepared by adding silica aerogel particles of three different particle sizes (powder, granules and bead) to unsaturated polyester resin with a fixed volume fraction of 30%. Thermogravimetric and thermal conductivity studies revealed that silica aerogel composites were having higher thermal stability and thermal insulation than the neat resin. It was suggested that the preservation of aerogel pores from resin intrusion is important for better thermal properties. Larger silica aerogel particles have more porous area (unwetted region) which results in a lower degradation rate and lower thermal conductivity of the base polymer. However, the addition of silica aerogel into resin has reduced the tensile modulus of the polymer matrix where smaller particle size displayed higher toughness than those with bigger particle size.

Interpenetrating organic–inorganic network: A short review on aerogel as a nanoporous filler in epoxy nanocomposite

“…The work by Salimian and colleagues on epoxy‐silica aerogel nanocomposites bolsters this point . On the basis of IOIN structure, nanopores of the silica aerogels have been entirely impregnated by epoxy to form silica nanoparticle‐rich regions where the interconnected silica nanoparticles are distributed evenly throughout the composite . The epoxy‐infiltrated aerogel phase is dispersed homogeneously in the polymer matrix and the epoxy‐filled aerogel phase itself can be considered as a high‐quality dispersion of linked silica nanoparticles in which the epoxy was penetrated into and fully occupied the mesopores (Figure , TEM image) …”

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

“…Further, oxygen is bonded to this polymer to form silane bonds (Si-O-Si) [3]. Based on its preparation methods, silica gel can be classified into three types, such as aqua gel [4], xerogel [5] and aerogel [6]. Characteristically, the aqua gel type of silica gel that has frequent water-filled holes.…”

Inclusion of Hydrophobic Liquids in Silica Aerogel Microparticles in an Aqueous Process: Microencapsulation and Extra Pore Creation

“…This technique involves an exchange with a nonpolar solvent and a surface hydrophobization of the silica skeleton with a silylation process. Silica aerogel has a very high potential for applications. , Besides the most promising and already commercialized application for thermal insulation, , silica aerogel can also be used in catalysis, sensors, nuclear particle detection, waste management, optics, electronics, medicine, personal care, etc. , Microparticulate aerogels can be of great interest for applications, e.g., as additives or where a large external surface is required. − Silica aerogel microparticles can be obtained by milling monoliths, which, however, may damage the pore structure and result in an irregular shape. Methods that allow the direct production of aerogel microparticles were reported, − and all of them were based on emulsification of silica sol in a nonpolar solvent and subsequent drying.…”