Polyvinylidene Fluoride-Embedded AgNW Films Covered with CTAB-Functionalized rGO for Highly Performing Flexible Transparent Heaters

Reduced graphene oxide (rGO) has shown great potential as a conductive material for flexible, transparent conducting electrodes (TCEs). However, poor dispersion of rGO in solvents limits its film-forming ability and integration with other nanomaterials. In this work, we address these challenges by employing a surfactant, cetyltrimethylammonium bromide (CTAB), as a noncovalent functionalizing agent to enhance the dispersion of rGO aided by electrostatic and hydrophobic stabilization without compromising its electronic structure. The CTAB-functionalized rGO was uniformly coated over AgNWs, which acted as a better protective overcoating in comparison to conventional rGO/AgNW systems, which could not harness the intrinsic properties of rGO. The AgNWs coated with rGO-CTAB were further embedded in poly(vinylidene fluoride), and the overall AgNW/rGO-CTAB/PVDF hybrid flexible films were investigated for their heating performance. The hybrid film demonstrated sheet resistance and transparency of 8 Ω/sq and 81%, respectively, and remarkably, the film attained a surface temperature of 160 ± 5 °C at an applied voltage of 4 V, demonstrating rapid heating behavior within a short response time of 70 s. These types of film heaters are suitable for various electronic applications such as automobile and military vehicle windshields and as wearable electronics under extremely low-temperature conditions.