Polymer Nanocomposites
with UiO-Derived Zirconia Fillers
for Energy Generation and Pressure-Sensing Devices: The Role of Crystal
Structure and Surface Characteristics
posted on 2024-03-07, 06:30authored byGargi Mukherjee, Ankur Verma, Arjun Hari Madhu, Bhagavatula L. V. Prasad, Subash Cherumannil Karumuthil
Piezoelectric energy harvesting and pressure sensing
using polymer
nanocomposites have opened up promising avenues in the field of flexible
electronics. Herein, the influence of varying crystal structures of
zirconia nanoparticles on a piezoelectric energy-generating zirconia-poly(vinylidene
difluoride) (PVDF) composite is investigated, and the fabrication
of a security alert pavement unit using the material with an optimized
composition is demonstrated. More specifically, two metal–organic
frameworks, UiO-66 and UiO-67, were employed to synthesize four different
types of zirconia nanoparticles with precise control
of the monoclinic and tetragonal phases. Polymer nanocomposite with
monoclinic zirconia nanoparticles derived from UiO-66 (ZrO2-66m) performed better than other derivatives with 61% enhancement
in the β phase with respect to pure PVDF. It was hypothesized
that the stable crystalline structure of the monoclinic phase might
act as a better nucleating agent, and among monoclinic derivatives,
ZrO2-66m was found to be more hydrophobic, probably enabling
a better interaction with PVDF. Subsequently, a prototype device with
a PVDF-ZrO2-66m (P/66m) film was made and tested for its
energy generation. The maximum output voltage generated by the device
under an irregular biomechanical hand tapping force of 8–9
N was 80 V, while the maximum open circuit current was found to be
65 μA. The prototype displayed a power of 2162.24 μW at
a load resistance of 1 MΩ. A laboratory scale demonstration
was executed with the prototype as an energy-generating and security
alert pavement unit. A wireless, Bluetooth-based security alert system
supported by an Android application was developed and demonstrated
as a promising application with the fabricated prototype. The results
and demonstrations validate that the PVDF-monoclinic ZrO2 nanoparticle nanocomposites will be an excellent value addition
for flexible, durable energy generation and pressure-sensing applications.