PVDF Composite as the 4D Solution For Heritage Structures

The 4D properties of thermoplastic composites prepared by mechanical blending for different engineering applications such as sensors, electromagnetic shielding equipment, piezoelectricity, etc. has been widely reported. But hitherto less has been testified on the 4D capabilities of chemically assisted mechanically blended (CAMB) thermoplastic composite for repair and maintenance of cracks in heritage buildings. This study outlines a novel solution for repairing heritage structure by using the 4D behavior of polyvinylidene fluoride (PVDF) composite prepared by CAMB graphene and Mn-doped ZnO with dimethylformamide (DMF) as solvent. The 3D printed electro-active composite has magnetic retention property (magnetization 4.27 emu/g) capable of self-assembly. The piezoelectric coefficient (D 33 ) 61.3pC/N was observed for the selected composite which justifies the development of β -phase required for crack repairing in heritage structure. Further, the 4D capability was investigated by strain measurement (for self-expansion and contraction) from the strain-electric field (S-E) loop. The bonding characteristics of 3D printed functional parts prepared with CAMB have been counter verified by photoluminescence (PLS) and Fourier transformed infrared (FTIR) spectroscopy analysis. The observed thermal stability (with improved heat capacity (33.62 J/g) and crystallinity (62.26%) in three repeated cycles) and Young’s modulus (793.04 MPa) observations along with dynamic mechanical analysis (DMA) justify the use of selected composite. The pre-straining of samples was also performed to investigate shape recovery with thermal stimulus.