Boosting the electro-mechanical coupling of piezoelectric polyvinyl alcohol–polyvinylidene fluoride blends by dispersing nano-graphene platelets

Abstract

Abstract Water-soluble polyvinyl alcohol (PVA) mixed with piezo-active polyvinylidene fluoride (PVdF) micro-grains constitute hybrid blends for transfusing mechanical energy to electrical energy. In principle, the value of the piezoelectric coefficient is a portion of the value that neat PVdF exhibits. In the present work, we investigate the possibility of augmenting the total electromechanical coupling by dispersing nano-graphene platelets (NGPs). Mechanical stress applied on structurally and compositionally heterogeneous solids results in increased values of the internal local stress field: NGPs are likely to amplify the local stress exercised on the surface of individual piezoelectric polymer grains. PVA–PVdF (3:1 w/w), cast from a water solution, loaded with various fractions of NGPs boost the value of the overall piezoelectric coefficient by 150% per weight fraction of NGPs and becomes superior to values reported for neat electro-active PVdF.