One-Pot Synthesis and Characterization of Polyrotaxane–Silica Hybrid Aerogel

Abstract

A novel kind of polyrotaxane–silica hybrid aerogel is successfully prepared via one-pot sol–gel synthesis in this work. The polyrotaxane can chemically interpenetrate with Si particles homogeneously in nanoscale, so as to shorten the gelation time and construct a flexible and mechanically strong skeleton. The supramolecular effect ascribable to the sliding motion of cyclic components in polyrotaxane is introduced into the hybrid aerogel for the first time. Compared with the brittle pure silica aerogel, the obtained polyrotaxane–silica hybrid aerogels show very low density, low thermal conductivity, and more than two orders magnitude improvement in the compression strength without compromising transparency.

Superflexible Multifunctional Polyvinylpolydimethylsiloxane‐Based Aerogels as Efficient Absorbents, Thermal Superinsulators, and Strain Sensors

“…However,t raditional aerogels are usually dried via costly supercritical drying (SCD) and exhibit low mechanical strength because of their intrinsically fragile/brittle networks,w hich need to be addressed before their practical applications.To overcome the costly drying process and brittleness, many efforts have been made to lower the cost by ambient pressure drying (APD), [23] freeze drying (FD) [22] and vacuum drying (VD), [24] and reinforce the aerogels by av ariety of methods.C ross-linking of aerogels with organic polymers is aw idely used method to reinforce the aerogels but usually results in lower porosity and higher density that limit their applications. [25,26] Flexible polymer-based aerogels can be obtained from resorcinol-formaldehyde, [27] poly(vinyl alcohol), [28] and supramolecules, [29] and some of them exhibit good absorption of organic solvents/oils.A nother kind of aerogels based on biomass such as nanocellulose and chitosan with compressibility and bendability have been reported. [30,31] Owing to their highly porous nanostructure that is composed of nanofibers,t hey show excellent thermal insulation performances.B esides,a ssembly of nanofibers via as pecific method can give compressible and elastic cellular aerogels with high pressure-sensitivity and good absorption/separation properties.…”

Versatile Double-Cross-Linking Approach to Transparent, Machinable, Supercompressible, Highly Bendable Aerogel Thermal Superinsulators

“…Hybridization of aerogels with organic compounds is widely studied to improve their mechanical properties. [11][12][13] Unfortunately, most traditional organic-inorganic hybridization strategies resulted in a significant decrease in porosity, SSA and transparency and a significant increase in density and thermal conductivity.…”

Precipitated silica agglomerates reinforced with cellulose nanofibrils as adsorbents for heavy metals

“…Silica has attracted and continues to gather global attention because of its fascinating properties and unique attributes including low dielectric constant (1.1-2.2), low index of refraction ($1.05) and ease of surface modication. 1,2 These properties are required in numerous applications such as thermal insulation, cosmic dust collectors, oral detoxication, catalysis, separation of oils and organic liquids, sensors, heavy metal aqueous waste remediation, oil spill clean-up and many others. [3][4][5][6] Amongst these, heavy metal removal by silica and silica-based adsorbents has been extensively investigated.…”

“…7 However, their poor mechanical properties dictated by their skeletal brittleness are some of the underlying problems which limit their wide application. 1,8 The silica skeletal brittleness can be solved by employing reinforcements in the form of polymers via chemical surface crosslinking chemistries, strengthening the silica with multifunctional nanoparticles or treatment with silylating agents 9 and networking with and/or in 1D brous materials. 10 Successful reinforcement of silica with multifunctional nanoparticles in the recent past was demonstrated by Harb et al 11 whereby graphene oxide and carbon nanotubes were employed via hydrolytic condensation of tetraethoxysilane.…”