Facile and efficient chitosan-based hygroscopic aerogel for air dehumidification

Xinhong Han; Yiwen Xue; Rui Lou; Shaoqiu Ding; Shurong Wang

doi:10.1016/j.ijbiomac.2023.126191

Facile and efficient chitosan-based hygroscopic aerogel for air dehumidification

Int J Biol Macromol. 2023 Aug 12:251:126191. doi: 10.1016/j.ijbiomac.2023.126191. Online ahead of print.

Authors

Xinhong Han¹, Yiwen Xue¹, Rui Lou², Shaoqiu Ding¹, Shurong Wang³

Affiliations

¹ State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China.
² College of Physics and Energy, Shaanxi University of Science and Technology, Xi'an 710021, China.
³ State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China. Electronic address: srwang@zju.edu.cn.

PMID: 37573918
DOI: 10.1016/j.ijbiomac.2023.126191

Abstract

Sorption dehumidification, as an energy-saving and eco-friendly approach, has been emerging in application for air dehumidification. Here, a prospective method is proposed to prepare biomass-based hygroscopic aerogels that are easily applicable, sustainable, high-efficient, and recyclable. The chitosan-based aerogel with a porous and hydrophilic network acts as the carrier and water reservoir for the uniformly distributed lithium chloride hygroscopic salt, and provides the hygroscopic salt with more liberal water channels to facilitate moisture capture and transfer. As a consequence, the prepared chitosan/polyvinyl alcohol@lithium chloride (chitosan/PVA@LiCl) hygroscopic aerogel exhibits an excellent moisture absorption capacity of up to 2.77 g g^-1 at a relative humidity of 90 %. Meanwhile, as the chitosan/PVA@LiCl aerogel is set in a closed space about 2200 times larger than its own volume, the relative humidity can be reduced from 90 % to 32 % within 2 h, and further lower to 25 % after 4 h. Furthermore, combined with multi-walled carbon nanotubes, the photothermal hygroscopic aerogel is obtained that can rapidly desorb water under sunlight, thus to realize energy-free cycle. Overall, the renewable biomass-based aerogel materials with the advantages of simple preparation and excellent hygroscopic performance provides a new path for the development of sorption dehumidification technology.

Keywords: Biomass; Chitosan; Dehumidification; Hygroscopic aerogels; Lithium chloride.