Preparation of antimicrobial anti-swelling conductive hydrogels based on polyaniline and their applications

Conductive hydrogels are ideal candidates for flexible sensor devices. However, in the practical application process, the high cost of conductive hydrogel, poor mechanical properties, limited sensing detection range, single function, environmental protection, and other issues, seriously hindered its practical application. To develop an electrically conductive hydrogel with excellent mechanical properties, low-cost, environmentally friendly, and multifunctional for a variety of complex application environments, polyvinyl alcohol (PVA) and the conductive polymer polyaniline (PANI) were selected to form a double network structure of the hydrogel body, and phytic acid (PA) and boronic acid (BA) were used as cross-linking agents to construct a low-cost, environmentally friendly, high-strength, and multifunctional PVA/PANI/PA/BA conductive hydrogel. The mechanical properties, microstructure, electrochemical properties, swelling resistance, and antimicrobial properties of composite hydrogels with different ratios of PVA/PANI were investigated, and the sensing performance of sensors based on this conductive hydrogel was discussed. It is shown that in the composite system with 15% PVA mass fraction, this hydrogel has excellent tensile strength (breaking stress up to 357 kPa, deformation at break up to 504%), good electrochemical properties (electrical conductivity of 146 mS/m), excellent resistance to swelling (the swelling rate is only 4.56% for 15 days of immersion, and the changes in breaking strength and elongation at break do not exceed 20% and 0.1%, respectively), and excellent antimicrobial properties, achieving a balance of functions. When sensors made based on this hydrogel are used to monitor the real-time movement of the human body, they can convert brows, finger, and wrist movement signals into stable electrical signals, which can be used in fields such as electronic skin and wearable sensors.