A Study Of Different Forms Of Energy Conversion And Sensing Performance Of Dual-response PVDF-HFP-based Flexible Composite Films

Energy sources such as mechanical energy or solar radiation in the environment are abundant,clean and sustainable,and flexible piezoelectric materials are capable of converting low-frequency biomechanical energy from these environmental energies into electrical energy,so the development of high-performance flexible polymer materials is an important strategy to solve the energy crisis that currently exists.In this paper,multifunctional composites based on polyvinylidene fluoride-hexafluoropropylene(PVDF-HFP)are designed and prepared to convert low-frequency mechanical energy and solar heat in life into instant electrical energy,and realize the application of flexible composite films in force-electric conversion,photoelectric conversion,and flexible sensing.Firstly,a flexible thin-film material with dual stimulus response to pressure and light was designed and prepared by using a chemically modified reduced graphene oxide strategy,which also enhanced the dielectric and piezoelectric properties of the pure polymer film and improved its charge storage performance,while the filler rGO-PFOES was confirmed to have better photothermal performance than graphene by DFT computational simulations and was consistent with the experimentally obtained results Consistent with the experimentally obtained results,an open-circuit voltage of 1.2 V and a short-circuit current of 25 nA can be generated under standard solar illumination.Secondly,a thin film with uniform porous micro-nano structure was prepared by the phase transition method,which improved the response sensitivity of the film to mechanical forces,while a multifunctional polymer film with high performance piezoelectric properties and charge retention properties was designed and prepared by using PFOES to modify r GO and improve its dispersion in PVDF-HFP matrix,and its application to photothermal and thermoelectric generators was tried The possibility of its application in photothermal and thermoelectric generators was tried,which provides a broader scope for the application of porous composite films.Finally,by combining thermoplastic polyurethane(PU),which can bond well with fabric,with PVDF-HFP,an elastomeric composite film with good piezoelectric properties,frictional electrical properties and high tensile properties was prepared using a co-blending method.Then a simple flexible wearable sensor based on elastic bandage was further designed by using PU/PVDF-HFP film,applying it to the detection of human muscle and joint movements.