Chitosan/silica hybrid aerogels with synergistic capability for superior hydrophobicity and mechanical robustness

Sizhao Zhang; Yanrong Liao; Kunming Lu; Zhao Wang; Jing Wang; Linzhe Lai; Wangwang Xin; Yunyun Xiao; Shixian Xiong; Feng Ding

doi:10.1016/j.carbpol.2023.121245

Chitosan/silica hybrid aerogels with synergistic capability for superior hydrophobicity and mechanical robustness

Carbohydr Polym. 2023 Nov 15:320:121245. doi: 10.1016/j.carbpol.2023.121245. Epub 2023 Aug 1.

Authors

Affiliations

¹ Polymer Aerogels Research Center, Jiangxi University of Science and Technology, Nanchang 330013, Jiangxi, China; Science and Technology on Advanced Ceramic Fibers and Composites Laboratory, National University of Defense Technology, Changsha 410073, Hunan, China; Postdoctoral Research Station on Mechanics, College of Aerospace Science and Engineering, National University of Defense Technology, Changsha 410073, Hunan, China. Electronic address: sinchawchang@126.com.
² Polymer Aerogels Research Center, Jiangxi University of Science and Technology, Nanchang 330013, Jiangxi, China.
³ Polymer Aerogels Research Center, Jiangxi University of Science and Technology, Nanchang 330013, Jiangxi, China. Electronic address: dingfengjl@163.com.

PMID: 37659825
DOI: 10.1016/j.carbpol.2023.121245

Abstract

Chitosan aerogels could be applied potentially in thermal insulation for energy-saving buildings, separation/adsorption, and catalysis. However, disadvantages of chitosan aerogels include their hydrophilicity and low insufficient mechanical strength. Here we propose a silica-phase hybriding route to create chitosan/silica hybrid aerogels with a synergistic capability for favourable hydrophobicity and superior mechanical strength, demonstrating an emergent finding (hydrophobicity optimised with the improved mechanical strength). The aerogels exhibit low drying shrinkage (as low as 13.41 %), lightweight (lowest to 0.149 g cm^-1), high-efficient thermal insulation (thermal conductivity as low as to 0.024 W m^-1 K^-1 at room temperature and normal pressure) either under cryogenic (-196 °C) or high-temperature conditions, exceptional fire-retardancy (self-extinguishing in 1.8 s) and environmentally friendly characteristic (initial mineralisation after 10 d). High hydrophobic property (water contact angle up to 142°) of the aerogels were achieved depending upon 1H, 1H, 2H, 2H-perfluorodecyltriethoxysilane of vapor deposition, presenting a discovery concerning substantial improvement of mechanical properties (up to 0.188 MPa at 5 % strain, increased by 25 %). Furthermore, we demonstrate that a plausible mechanism for simultaneous hydrophobic and mechanical enhancement is depending upon the modulation of networking skeletons at the nanoscale.

Keywords: Aerogel; Chitosan; Hydrophobicity; Mechanical property; Silica hybriding.