Nanomaterial based PVA nanocomposite hydrogels for biomedical sensing: Advances toward designing the ideal flexible/wearable nanoprobes.

• Reinforcement of polyvinyl alcohol (PVA) nanocomposites blend using Mg 0.5 Zn 0.5 Fe 2 O 4 nanoparticles. • The interaction of PVA and nanoparticles in nanocomposites samples was confirmed by FTIR, which showed shifting bands in FTIR spectra. • Loss factor and dielectric constant show a decreasing trend, with variable amounts of nanoparticles and constant polymer concentration. Significant progress has been done in the synthesis of polymer nanocomposites owing to their great application in various fields like in devices, limiting diodes, photodetectors, solar cells, and spin-coating. The present study deals with the incorporation of polyvinyl alcohol (PVA) nanocomposites blend using Mg 0.5 Zn 0.5 Fe 2 O 4 nanoparticles. The Micro-emulsion method has been utilized to synthesis Mg 0.5 Zn 0.5 Fe 2 O 4 nanoparticles and after that implanted into PVA network via ultrasound-assisted liquid-phase approach. This method can be used to solve problems with nanoparticles dispersion and stabilization in the PVA matrix. Under ultrasonication, the aggregation of nanoparticles was found to be reduced. Transmission electron microscopy (TEM) revealed that PVA chains have encircled the Mg 0.5 Zn 0.5 Fe 2 O 4 nanoparticles, which is further verified by Fourier-transform infrared spectroscopy (FTIR) peak shifting values. The X-ray diffraction (XRD) patterns demonstrated that the composite crystalline structure is single-phase cubic. The crystallite size for the largest peak (1 1 1) increases gradually from 31.49 to 43.79 nm by increasing the concentration (0.1–0.5 g) of nanoparticles with PVA. The interaction of PVA and nanoparticles in nanocomposites samples was confirmed by FTIR, which showed shifting bands in FTIR spectra. Loss factor and dielectric constant show a decreasing trend, with variable amounts of nanoparticles and constant polymer concentration. The dielectric properties of with variation of nanoparticles revealed that these materials might be considered a good candidate for modern devices like memristors, and Random access memories (RAM). 

Synthesis, structural and dielectric properties of Mg/Zn ferrites -PVA nanocomposites

Synthesis and application of graphene-based sensors in biology: a review

Synergistic effect of barium titanate nanoparticles and graphene quantum dots on the dielectric properties and conductivity of poly(vinylidenefluoride-co-hexafluoroethylene) films

PVDF-HFP/BaTiO3/GQDs polymer nanocomposite films with good flexibility and high dielectric constant (ϵ) at low frequency were prepared via solution casting technique. Different compositions of BaTiO3 (non-conducting ceramic nanofiller) and Graphene quantum dots (GQDs) (conducting nanofiller) utilized as co-filler were embedded in poly (vinylidene fluoride-co-hexafluoroethylene) (PVDF-HFP) polymer matrix. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and Scanning electron microscopy (SEM) techniques were employed to characterize the prepared nanocomposite films. The mechanical properties of PVDF-HFP/BaTiO3/GQDs nanocomposite films were also investigated. Dielectric properties of nanocomposite films such as dielectric constant (ϵ), dielectric loss (tanδ) and AC conductivity ( σac ) were also determined as a function of frequency and temperature. Highest ϵ with relatively low tanδ obtained at low frequency for maximum temperature in all polymer nanocomposite films. The σac increases from lower (100 Hz) to higher frequency up to 100 kHz and drops to zero for the further increment of frequency. These results suggest that the PVDF-HFP/BaTiO3/GQDs nanocomposites are the most promising materials for energy storage applications. 

M. Mohamed Naseer Ali

Papers

Structure, morphology and modelling studies of polyvinylalcohol nanocomposites reinforced with nickel oxide nanoparticles and graphene quantum dots.