Preparation of CS/CNT/PAM-U composite hydrogels with excellent pressure sensitivity by in-situ polymerization of terpolymer DES and properties

Abstract Deep eutectic solvent (DES) was prepared using choline chloride (ChCl), acrylamide (AM) and urea (U) as raw materials. CS and N-CNTs were added to DES as fillers, and composite hydrogels were prepared by in-situ polymerization (SP). The composite hydrogels were characterized and analyzed by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). In this paper, the pressure sensitivity, electrical conductivity, swelling and mechanical properties of the composite hydrogels were analyzed. The results showed that the pressure sensitivity of the composite hydrogels increased significantly after CS and N-CNTs were introduced into the hydrogels as fillers. When the filler content reached the highest, the pressure sensitivity of the composite hydrogels increased by 13 times compared with that of the hydrogels without filler. Due to the electrical conductivity of CS and N-CNTs, the higher the filler content, the stronger the electrical conductivity of the composite hydrogel, and the enhancement of electrical conductivity also has an impact on the pressure sensitivity of the composite hydrogel. This study provides a preparation method of composite hydrogel with excellent conductivity and pressure sensitivity.