Improving stretchability, self-healing, adhesion, strain sensing, and electromagnetic interference shielding in dual-protein hydrogels via graphitized carbon nanosheet-mediated colloidal network

Constructing sustainable hydrogel systems with simultaneous excellent mechanical properties, stable electromechanical response, and efficient electromagnetic attenuation is still a challenge. Herein, an all-biomass multifunctional composite hydrogel was developed based on a dual-protein network composed of silk fibroin (SF) and wool keratin (WK). Tannic acid (TA) was introduced as a dynamic crosslinker to reinforce intermolecular interactions, while highly graphitized carbon nanosheets (HGCN) derived from wheat straw were incorporated as conductive fillers to establish an interconnected electron transport pathway. The results revealed a composition-dependent trade-off between mechanical strength and multifunctional performance. The 30% GC-WKSF hydrogel exhibited the highest tensile strength of 757.0 kPa along with excellent adhesion and a self-healing efficiency of 91.81%. Increasing the HGCN content to 40% led to enhanced electrical conductivity (0.61 S·m⁻¹), strain sensing performance (gauge factors of 0.46 and 0.72), and electromagnetic interference (EMI) shielding effectiveness (30.84 dB in the X-band) indicating a favorable balance between conductivity and multifunctionality. This work provides fundamental insights into the synergistic mechanisms between biomass-derived carbon fillers and dual-protein networks and offers a sustainable strategy for designing biomass-based multifunctional hydrogels for flexible electronics, wearable sensors, and electromagnetic protection applications. Download: Download high-res image (351KB) Download: Download full-size image