A nanocellulose/SiO2 composite aerogel with improved oil adsorption capacity and high thermal insulation performance

Abstract

Nanocellulose-based aerogels are exceptional next-generation oil adsorbents for efficient oil removal, offering sustainability, structural superiority, and tunable functionality. Nevertheless, current nanocellulose-based adsorbents are limited by moderate oil adsorption capacity and poor thermal insulation performance, which are essential for specific high-stakes applications. In this study, a nanocellulose/SiO₂ composite aerogel with high oil adsorption capacity and good thermal insulation performance was synthesized via one-pot synthesis using active silanol, methyltrimethoxysilane (MTMS), and hexadecyltrimethoxysilane (HDTMS). The effects of preparation conditions (the nanocellulose concentration, tert-butyl alcohol content, active silanol content, MTMS content, and HDTMS content) on its oil adsorption performance were explored. The results indicate that the nanocellulose/SiO₂ composite aerogel exhibited a three-dimensional porous structure with improved hydrophobicity (contact angle up to 149.2°), resulting in excellent oil adsorption capacity (up to 131.2 g g⁻¹) and thermal stability (no significant weight loss below 320 °C). Furthermore, the as-prepared aerogel showed superior thermal insulation performance, as reflected by a low surface temperature (65.7 °C) compared to unmodified nanocellulose (84.3 °C) when exposed to a 120 °C heat source. This study paves the way for efficient oil spill remediation and thermal management in demanding environments using nanocellulose aerogel-based adsorbents.