Conductive graphene-containing biocompatible films

In this work, we studied the preparation of graphene dispersions by liquid-phase ultrasound exfoliation in aqueous solutions, using amphiphilic stabilizers, such as Pluronic F108 (Plu) and polyvinylpyrrolidone (PVP), as well as in N-MP. The resulting dispersions were characterized by TEM, dynamic light scattering, UV spectroscopy. Optimal conditions for ultrasonic treatment of few-layer graphene dispersions were established, which make it possible to obtain stable concentrated graphene dispersions (1–4 layers) with lateral dimensions of 50–2000 nm. Based on the developed graphene dispersions, composite films with various polymer matrices (polylactide, collagen, chitosan), using graphene as nano-filler, were obtained. The presence of the latter provided electrical conductivity up to 0.9 S cm⁻¹, a change in electrical resistance during deformation with a strain sensitivity coefficient of 1.3–5.7, as well as an increase in breaking stress up to 97.1 ± 1.6 MPa and in elastic modulus up to 3.99 GPa. The designed films possess a wide variety of properties and are promising for use as flexible biosensors for biomechanical studies and electrically conductive matrices for tissue engineering.