Unusual Flexibility of Transparent Poly(methylsilsesquioxane) Aerogels by Surfactant-Induced Mesoscopic Fiber Assembly

Abstract

We report a new synthetic strategy to realize highly transparent aerogels with outstanding bending flexibility. Taking poly(methylsilsesquioxane) (PMSQ) aerogels as an example, surfactant-induced fiber-like mesoscopic assembly of PMSQ and poly(ethylene oxide)-block-poly(propylene oxide)-block-poly(ethylene oxide) (PEO-b-PPO-b-PEO, so-called Pluronics) has been demonstrated. The obtained PMSQ aerogels possessed a characteristic branched fibrous structure in the mesoscale. With employing various kinds of PEO-b-PPO-b-PEO as the structure determining agent, optimization of the mesoscale structure of PMSQ gels has realized highly transparent aerogels with outstanding bendability compared to those reported in previous works. This approach provides a novel way to thermally superinsulating flexible devices with glasslike transparency.

Homogeneous silicone network formation in aqueous sol–gel systems toward low-density porous materials

“…Pluronic surfactant and organic strong base, tetramethylammonium hydroxide (TMAOH), instead of ammonia from urea. 27) It was found that the one-dimensional (1D) fibrous skeletons in the meso scale is obtained presumably through hydrogen bonding between silanol and ether oxygen in the Pluronic surfactant, and adequate control of pH higher than those achieved with urea results in a uniform mesoporous structure with a 1D feature. A typical sample prepared in the presence of Pluronic P105 (EO 37 PO 56 EO 37 , M w = 6500) shows outstanding bending flexibility (Fig.…”