Integration of carbon quantum dots with thermoplastic polyurethane for flexible and human-comfortable composite membrane

In this study, the carbon quantum dots/thermoplastic polyurethane (CQDs/TPU) flexible composite film is prepared by solvent and electrospinning methods. The effects of CQDs concentrations on the microstructure, mechanical property, breathable moisture-permeable property, and sensing performance of the composite films are investigated. Results show that the composite film prepared by solvent method has a large strain range, and its sensitivity increases with strain, but exhibits poor breathable moisture-permeable property and linearity. The fibers inside the electrospinning composite membrane are arranged in a staggered manner to form a good three-dimensional conductive network. As the concentration of CQDs increases, the tensile strength at break gradually decreases and the tensile strength at break gradually increases. The composite film has good breathability and moisture permeability, with a maximum air permeability of 2.44 L/(m 2 ·s). The electrospinning method composite film has a smaller strain range but high sensitivity with a GF value of up to 53.3, better linearity, superior breathable moisture-permeable property and 4.67 times of air permeability compared to the composite film by solvent method.