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

Abstract

ABSTRACT:A facile yet versatile approach to transparent, highly flexible, machinable, superinsulating organic-inorganic hybrid aerogels and xerogels is presented. This method involves radical polymerization of a single alkenylalkoxysilane to obtain polyalkenylalkoxysilane, and subsequent hydrolytic polycondensation to afford a homogeneous, doubly cross-linked nanostructure consisting of polysiloxanes and hydrocarbon polymer units.Here we demonstrate that novel aerogels based on polyvinylpolysilsesquioxane (PVPSQ),

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

“…Moreover,a no rganic-inorganic double-cross-linking approach has been found to prepare transparent polyvinylpolymethylsiloxane (PVPMS), polyallypolymethylsiloxane (PAPMS), polyvinylpolysilsesquioxane (PVPSQ), and polyallypolysilsesquioxane (PAPSQ) aerogels with high flexibility, processability,a nd excellent thermal insulation properties. [39,40] Herein, we report unprecedented doubly cross-linked aerogels based on polyvinylpolydimethylsiloxane (PVPDMS) with excellent mechanical properties,s uch as superflexiblity and processability and multifunctionality combining thermal insulation, selective absorption, and strain sensing properties via the double-cross-linking strategy consisting of free-radical polymerization/hydrolytic polycondensation without any additional organic cross-linkers.F ree radical polymerization of asingle precursor vinyldimethylmethoxysilane (VDMMS) or co-polymerization of precursors VDMMS and vinylmethyldimethoxysilane (VMDMS) in the presence of ar adical Supportinginformation and the ORCID identification number(s) for the author(s) of this article can be found under: https://doi.…”

“…Moreover,a no rganic-inorganic double-cross-linking approach has been found to prepare transparent polyvinylpolymethylsiloxane (PVPMS), polyallypolymethylsiloxane (PAPMS), polyvinylpolysilsesquioxane (PVPSQ), and polyallypolysilsesquioxane (PAPSQ) aerogels with high flexibility, processability,a nd excellent thermal insulation properties. [39,40] Herein, we report unprecedented doubly cross-linked aerogels based on polyvinylpolydimethylsiloxane (PVPDMS) with excellent mechanical properties,s uch as superflexiblity and processability and multifunctionality combining thermal insulation, selective absorption, and strain sensing properties via the double-cross-linking strategy consisting of free-radical polymerization/hydrolytic polycondensation without any additional organic cross-linkers.F ree radical polymerization of asingle precursor vinyldimethylmethoxysilane (VDMMS) or co-polymerization of precursors VDMMS and vinylmethyldimethoxysilane (VMDMS) in the presence of ar adical initiator (di-tert-butyl peroxide,DTBP) is followed by hydrolytic polycondensation of the obtained polymers with astrong base catalyst (tetramethylammonium hydroxide,T MAOH) to give ad oubly cross-linked porous structure consisting of flexible polydimethylsiloxanes (/polymethylsiloxanes) and hydrocarbon chains.A erogels based on the PVPDMS network and PVPDMS/polyvinylpolymethylsiloxane (PVPMS) copolymer network are then obtained via low-cost APD or FD.H ighly flexible and conductive PVPDMS/PVPMS/graphene nanocomposite aerogels with astrain sensing property have also been prepared by ahomogeneous incorporation of graphene nanoplatelets in the hydrolytic polycondensation process.S ynthetic approaches toward an excellent combination of these functionalities in as ingle material system are discussed from the viewpoint of structure-,property relationship.…”

Elastic methyltrimethoxysilane based silica aerogels reinforced with polyvinylmethyldimethoxysilane

“…17 Thus, aerogels reinforced by these polymers usually exhibit heterogeneous core-shell structures, 1 which would be unfavorable to satisfy the requirements of silica aerogels with light weight, high surface area, and excellent insulation performance. Recently, Kanamori's group [23][24][25] has reported an innovative approach to prepare doubly cross-linked polyvinylpolydimethylsiloxane-based aerogels. This novel and facile preparation of the double-cross-linking structure is based on consecutive processes involving radical polymerization and hydrolytic polycondensation.…”

“…This novel and facile preparation of the double-cross-linking structure is based on consecutive processes involving radical polymerization and hydrolytic polycondensation. 25 In contrast to core-shell structures, the doubly cross-linked strategy is more conducive to forming homogeneous silica networks, avoiding obvious phase separation 23 and particles aggregation in the sol-gel process. Beneting from the organic bridge and homogeneous distribution of polyvinylmethyldimethoxysilane (PVMDMS) in silica networks, polyvinylpolydimethylsiloxane aerogels exhibit many merits, such as low density, uniform nanopores, high transparency, super compressibility, high bendability, excellent machinability, and thermal superinsulation.…”

“…Beneting from the organic bridge and homogeneous distribution of polyvinylmethyldimethoxysilane (PVMDMS) in silica networks, polyvinylpolydimethylsiloxane aerogels exhibit many merits, such as low density, uniform nanopores, high transparency, super compressibility, high bendability, excellent machinability, and thermal superinsulation. 24,25 However, the plastic deformation still exists in polyvinylpolydimethylsiloxane aerogel networks to some extent. These aerogels obtained by supercritical drying cannot rebound to their original height when the compressive stress is removed.…”