Piezoelectric properties of noncovalently functionalized 2D nanomaterials incorporated poly(vinylidene fluoride) nanocomposites

We report here for the first time the role of noncovalently functionalized 2D nanomaterials on the ferroelectric and piezoelectric behavior of poly(vinylidene fluoride) (PVDF) nanocomposites. Graphene oxide (GO), expanded graphite (EG) and hexagonal boron nitride (h-BN) were noncovalently modified via Li-salt of 6-amino hexanoic acid (Li-AHA), denoted as m-GO, m-EG and m-BN, in order to de-agglomerate and de-stack them, which were subsequently incorporated into the PVDF matrix via solution mixing, followed by compression molding. Simultaneously, PVDF nanocomposites with unmodified 0.08 wt% of 2D nanomaterials were also prepared using the same methodology. PVDF/m-BN nanocomposite showed a higher extent of polar phase (similar to 36%) associated with PVDF phase as compared to PVDF/m-GO and PVDF/m-EG nanocomposites. Further, the highest permittivity (similar to 58 at 10(-1) Hz) was achieved in PVDF/m-BN nanocomposite, which was also reflected in higher remnant polarization (similar to 61 nC/cm(2)) and a significantly higher d(33) value (similar to 53 pm/V). Moreover, a higher output peak to peak voltage (similar to 13 V) was obtained for the sensor device fabricated from PVDF/m-BN nanocomposite. Thus, the role of Li-AHA-modified 2D nanomaterials in improving the morphology, dielectric, ferroelectric, and piezoelectric characteristics of the PVDF nanocomposites was clearly established.