Robust Superhydrophobic Bridged Silsesquioxane Aerogels with Tunable Performances and Their Applications

Abstract

Aerogels are a family of highly porous materials whose applications are commonly restricted by poor mechanical properties. Herein, thiol-ene chemistry is employed to synthesize a series of novel bridged silsesquioxane (BSQ) precursors with various alkoxy groups. On the basis of the different hydrolyzing rates of the methoxy and ethoxy groups, robust superhydrophobic BSQ aerogels with tailorable morphology and mechanical performances have been prepared. The flexible thioether bridge contributes to the robustness of the as-formed aerogels, and the property can be tuned on the basis of the distinct combinations of alkoxy groups with the density of the aerogels almost unchanged. To the best of our knowledge, the lowest density among the ambient pressure dried aerogels is obtained. Further, potential application of the aerogels for oil/water separation and acoustic materials has also been presented.

Advanced Sorbents for Oil‐Spill Cleanup: Recent Advances and Future Perspectives

“…b) Tailoring the aerogel wettability by alkoxy groups. b) Reproduced with permission . Copyright 2015, American Chemical Society.…”

Silicone‐Based Organic–Inorganic Hybrid Aerogels and Xerogels

“…In other examples, organo‐bridged precursors containing C−S and C−O bonds in the bridging moiety were prepared by the thiol–ene reaction between 3‐mercaptopropyltrimethoxysilane/2,2′‐(ethylenedioxy)diethanethiol) and VTMS/vinyltriethoxysilane (VTES). Although these cases also demonstrate only opaque aerogels with macropores in the micrometer range, presumably due to enhanced phase separation by the more hydrophobic organic bridging groups, the resultant aerogels are flexible and can be dried in a facile way, for example, vacuum drying . The combination of hydrophobicity and flexibility in these materials is useful in the separation of oil and water just as demonstrated in the marshmallow‐like gels (Section 4.3).…”

“… a) Schematic representation of the hexylene‐bridged polysilsesquioxane aerogel and xerogel from BTMH. b) A photograph showing the bending property of a hydrophobized aerogel, and c) stress‐strain curves of three‐point bending on pristine and hydrophobized aerogels (density of both aerogels is 0.22 g cm −3 ) and the same of a silica aerogel at 0.20 g cm −3 for comparison …”

Lightweight foams of amine-rich organosilica and cellulose nanofibrils by foaming and controlled condensation of aminosilane

“…as thermal and acoustic insulation materials, 2 CO 2 3 and oil sorbents, and water purification filters. 4 Organosilica foams can be produced in several ways, including sol-gel processing of an organofunctional silane (OS), [5][6][7] co-gelation of an OS with tetra-alkoxysilanes 8,9 or post-modification of silica alcogels. 10 The sol-gel processing of the OS is done in a multistep (i to iv) process involving the use of an alcohol-water mixed solvent.…”