Xylan‑Assisted construction of anisotropic aerogel for pressure sensor

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Switzerland : 1996), 2024-06, Vol.490, p.151688, Article 151688
• Main Authors: Yan, Xueqing, Pan, Jing, Lv, Ziwen, Jia, Siyu, Wen, Xia, Peng, Pai, Rao, Jun, Peng, Feng
• Format: Article
• Language: English
• Subjects: Anisotropic aerogel; Dispersant; Pressure sensor; Xylan
• ISSN: 1385-8947
• DOI: 10.1016/j.cej.2024.151688

•Modified xylan with good amphiphilicity was obtained under mild reaction conditions by hydroxypropylsulfonation.•HSX exhibited a satisfactory dispersion efficiency of MWCNTs in water.•The aerogels were prepared by freeze-casting technology which reveals excellent mechanical performance.•The aerogel is utilized to construct a pressure sensor, which exhibit high sensitivity (S = 2.17 kPa−1) and impressive responsiveness. Currently, aerogels are promising for wearable pressure sensors due to their superior flexibility and high sensitivity. However, uniform dispersion of conductive solid filler is a critical step in the preparation process. Herein, xylan with good amphiphilicity was obtained by hydroxypropylsulfonation under mild reaction conditions, which is accepted as a dispersant for multi-walled carbon nanotubes (MWCNTs) in water. The hydroxypropylsulfonated xylan (HSX) exhibited a satisfactory dispersion efficiency reached to 97.8 %. After standing for 20 days, there are still 76 % of MWCNTs stabilized in the dispersion. Then, the ultralight, flexible and superstable anisotropic aerogels were prepared by freeze-casting technology. The obtained aerogel reveals excellent mechanical performance, with a great compressibility (undergoing a strain of 70 %) and elasticity (91.8 % height retention after 100 cycles at a strain of 20 %). As a proof of concept, the HSX/MWCNTs aerogel is utilized to construct a pressure sensor, which exhibit high sensitivity (S = 2.17 kPa−1) and impressive responsiveness to human motions. This work demonstrates a promising flexible electronic material for wearable electronics, electronic skin, and human motion monitoring.