Stretchable Zwitterionic Conductive Hydrogels with Semi‐Interpenetrating Network Based on Polyaniline for Flexible Strain Sensors

Abstract

Stretchable conductive hydrogels are of great significance in wearable electronic devices and tissue engineering scaffolds. In this paper, the zwitterionic polymer network hydrogels are synthesized by radical co-polymerizing acrylic acid (AA) and methyl acryloyl oxygen ethyl trimethyl ammonium chloride (DMC) in aniline (ANI) aqueous solution followed by oxidation polymerization of ANI to form semi-interpenetrating network hydrogel. The conductive hydrogels are endowed excellent mechanical properties by synergistic effect of electrostatic interaction and hydrogen bonding between the interpenetrating network of PANI and P(AA-co-DMC). The tensile strength reaches up to 0.173 MPa at 576% and the compression strength reaches up to 0.73 MPa at 80%. Meanwhile, the zwitterions and polyaniline ensure hydrogels to obtain conductivity (0.428 s m −1 ). In addition, the as-prepared conductive hydrogels can also be used as ionic skin to accurately monitor various movements of the human body, showing its potential applications in wearable devices and flexible electronic devices.

Robust conductive nanocomposite hydrogels with an interpenetrating network based on polyaniline for flexible supercapacitors

“…Absorption bands of the COO − groups shifted from 2932 and 1643 cm −1 to 2937 and 1646 cm −1 in the PAA/PANI/SiO 2 hydrogels, respectively, indicating that noncovalent bonds (such as hydrogen bonds, electrostatic interactions, and chain entanglements) formed between PAA/SiO 2 and PANI networks. Additionally, two unique PANI‐related bands (2346 cm −1 for the NCO bond and 1294 cm −1 for the CN within the benzenoid ring) were discovered in PAA/PANI/SiO 2 hydrogels, confirming the formation of PANI 21,38,39 . As shown in Figure 2B, there was no obvious difference between XRD patterns of PAA/PANI/SiO 2 and PAA/SiO 2 hydrogels.…”

“…Additionally, two unique PANI-related bands (2346 cm À1 for the N C O bond and 1294 cm À1 for the C N within the benzenoid ring) were discovered in PAA/PANI/SiO 2 hydrogels, confirming the formation of PANI. 21,38,39 As shown in Figure 2B, there was no obvious difference between XRD patterns of PAA/PANI/SiO 2 and PAA/SiO 2 hydrogels. They had a similar diffraction pattern with a broad peak at 18.4 and a weak peak at about 37.3 , which belonged to amorphous PAA and amorphous SiO 2 , respectively.…”

A highly conductive and ultra-stretchable polyaniline/cellulose nanocrystal/polyacrylamide hydrogel with hydrophobic associations for wearable strain sensors

“…HAPAAm/CNC/PAni-0.5 has an average GF of 3.7 (linear, R 2 = 0.986) within the strain range of 0-200%, comparable with highly sensitive PAni-based hydrogel strain sensors reported recently (Table S2 †). 12,25,[32][33][34][35][36]45,46 The excellent linearity of HAPAAm/CNC/PAni-0.5 can facilitate the signal calibration for medical applications. 10,47 However, the PAni conductive network appears to break while stretching the hydrogel by 500%.…”

“…The optimal hydrogel (HAPAAm/CNC/PAni-0.5) benets from high cross-linking density (pore size as low as z1 mm along with negligible swelling degree in DI water), high stretchability (z2400%), and great electrical conductivity (21.7 S m −1 ), superior to those of previously reported PAni-based hydrogels. 12,[16][17][18][19]25,[32][33][34][35][36] The hydrogel can sense a wide range of strains, from minor (1%) to large ones (1000%). It also shows linearity and high strain sensing (GF = 3.7) within the strain range of 0-200%.…”

Recent Progress in Biomedical Sensors Based on Conducting Polymer Hydrogels

“…A PVA–PEDOT:PSS SIPN hydrogel can also be fabricated using glutaraldehyde (GA) as the chemical cross-linker for PVA . On the other hand, a zwitterionic SIPN based on PANI and a copolymer of anionic acrylic acid (AA) and cationic methylacryloyl oxygen ethyl trimethylammonium chloride (DMC) was fabricated as a candidate for flexible strain sensors . In this work, the hydrogel from p­(AA- co -DMC) was first fabricated, followed by the polymerization of aniline using APS.…”