Flexible Pressure Sensor Based on PVDF Nanocomposites Containing Reduced Graphene Oxide-Titania Hybrid Nanolayers

Abstract

Abstract:A novel flexible nanocomposite pressure sensor with a tensile strength of about 47 MPa is fabricated in this work. Nanolayers of titanium dioxide (titania nanolayers, TNL) synthesized by hydrothermal method are used to reinforce the polyvinylidene fluoride (PVDF) by simple solution mixing. A hybrid composite is prepared by incorporating the TNL (2.5 wt %) with reduced graphene oxide (rGO) (2.5 wt %) synthesized by improved graphene oxide synthesis to form a PVDF/rGO-TNL composite. A comparison between PVDF, PVDF/rGO (5 wt %), PVDF/TNL (5 wt %) and PVDF/rGO-TNL (total additives 5 wt %) samples are analyzed for their sensing, thermal and dielectric characteristics. The new shape of additives (with sharp morphology), good interaction and well distributed hybrid additives in the matrix increased the sensitivity by 333.46% at 5 kPa, 200.7% at 10.7 kPa and 246.7% at 17.6 kPa compared to the individual PVDF composite of TNL, confirming its possible application in fabricating low cost and light weight pressure sensing devices and electronic devices with reduced quantity of metal oxides. Increase in the β crystallinity percentage and removal of α phase for PVDF was detected for the hybrid composite and linked to the improvement in the mechanical properties. Tensile strength for the hybrid composite (46.91 MPa) was 115% higher than that of the neat polymer matrix. Improvement in the wettability and less roughness in the hybrid composites were observed, which can prevent fouling, a major disadvantage in many sensor applications.

Advances in Piezoelectric Polymer Composites for Energy Harvesting Applications: A Systematic Review

“…Further, in 2017, Al‐Saygh et al . fabricated a PVDF‐based flexible pressure sensor containing rGO and TiO 2 nanolayers (TNL).…”

“…In 2016, Abdelhamid et al [98] prepared self-standing flexible PVDF composite films containing hybrid fillers (comprising rGO, ZnO, and Fe 3 O 4 nanoparticles) and investigated their dielectric behavior with respect to the filler type. A higher percentage of ß-phase content (80%) was reported for both pure PVDF and PVDF-rGO films whereas a reduction in the ß-phase amount (50%) was observed for PVDF-rGO-Fe 3 Further, in 2017, Al-Saygh et al [99] fabricated a PVDF-based flexible pressure sensor containing rGO and TiO 2 nanolayers (TNL). Higher ß-phase content (75.68%) for the hybrid PVDF/ rGO-TNL film was obtained as compared to PVDF (70.37%), PVDF/rGO (72.73%), and PVDF/TNL (73.5%) films.…”

An application‐oriented roadmap to select polymeric nanocomposites for advanced applications: A review

“…It has been widely used in electronic devices because of its low cost and structural stability. Combined with graphene oxide, titania has been investigated for flexible pressure sensors in combination with Polyvinylidene fluoride or polyvinylidene difluoride (PVDF), showing good dielectric properties, increased wettability, and reduced biofouling (accumulation of microorganisms on wetted surfaces) . In Table , other potential applications are listed, such as in textile application with antimicrobial and self‐cleaning properties along with the other information collected from the state‐of‐the‐art literature studies.…”

Stretchable quaternary phasic PVDF-HFP nanocomposite films containing graphene-titania-SrTiO3 for mechanical energy harvesting

“…A quantitative estimation of the crystallinity is done to understand the influence of hybrid nanofillers on the crystalline behavior of the PVDF-HFP. The relative amount of β and γ-phases of the samples are calculated [38,40] by following the two similar equations given below.…”

“…Since energy storage capacity is also important for those materials used in energy generating devices, analyzing the dielectric properties of current polymer nanocomposite systems has utmost significance [40]. The frequencydependent dielectric constant, dielectric loss, and conductivity values are provided in Fig.…”