Mechanically strong wood-based composite aerogels as oil adsorbents and sensors

Abstract

This work reported a top-down strategy to develop wood-based composites by combining wood skeleton (WS) aerogel with Polydimethylsiloxane (PDMS). WS aerogel was extracted by extensively removing lignin and hemicellulose from natural wood followed with freeze-drying. The hypothesis is that the introduction of hydrophobic PDMS into WS aerogel is of great importance for improving its mechanical performance and expanding the potential applications. To this end, WS/PDMS composites were developed by forming PDMS-infiltrated-wood skeleton via immersion and polymerization after curing treatment. We further adjusted the infiltrated PDMS concentration from 1 wt% to 30 wt% to explore the mechanical properties of the developed wood-based composite aerogels. As a result, both WS/PDMS-1 (with infiltration of 1 wt% PDMS) and WS/PDMS-30 (with infiltration of 30 wt% PDMS) performed significantly improved compression performance and shape stability compared with WS aerogel. Besides, with the assistance of surface-heating treatment on WS (HWS), the obtained HWS/PDMS-1 were used as adsorbing agents and showed fast adsorption rate with a capacity of 12 g/g (methyl silicone oil). Alternatively, by increasing the PDMS content, the obtained WS/PDMS-30 exhibited excellent compression strength and cycling stability, which could be assembled into sensor devices. We believe that this strategy may facilitate the development of strong wood-based composites with interesting features.