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ABSTRACT The present article deals with the preparation and characterization of pure and lead oxide (PbO) nanoparticles embedded polyvinyl alcohol (PVA) films by using a colloidal processing technique. PbO nanoparticles were successfully synthesized using the simple precipitation method. Polymer/ceramic-based flexible and self-standing films were obtained and further characterized using various analytical techniques. The mechanical and dielectric properties were also investigated. The Fourier Transform Infrared Spectroscopy (FTIR) results indicate that the structural characterization of PVA is strongly affected by the incorporation of PbO. Thermal analysis results indicate that the thermal stability of the PbO-doped PVA film has improved as compared with the neat PVA film. The mechanical property of nanocomposites has improved significantly due to an increase in filler loadings, indicating that a good interaction exists between PbO nanoparticles and PVA matrix. The dielectric constant of PVA/PbO nanocomposites has significantly improved with comparatively low dielectric loss values, indicating that the nanocomposites can be considered as an attractive material for embedded capacitor applications. [ABSTRACT FROM AUTHOR]

ABSTRACT In the present study, fumed silica (SiO2) nanoparticle reinforced poly(vinyl alcohol) (PVA) and poly(vinylpyrrolidone) (PVP) blend nanocomposite films were prepared via a simple solution-blending technique. Fourier transform infrared spectroscopy (FTIR), ultraviolet-visible spectroscopy (UV-vis), X-ray diffraction (XRD), and scanning electron microscopy (SEM) were employed to elucidate the successful incorporation of SiO2 nanoparticles in the PVA/PVP blend matrix. A thermogravimetric analyzer was used to evaluate the thermal stability of the nanocomposites. The dielectric properties such as dielectric constant (ɛ) and dielectric loss (tan δ) of the PVA/PVP/SiO2 nanocomposite films were evaluated in the broadband frequency range of 10−2 Hz to 20 MHz and for temperatures in the range 40-150 °C. The FTIR and UV-vis spectroscopy results implied the presence of hydrogen bonding interaction between SiO2 and the PVA/PVP blend matrix. The XRD and SEM results revealed that SiO2 nanoparticles were uniformly dispersed in the PVA/PVP blend matrix. The dielectric property analysis revealed that the dielectric constant values of the nanocomposites are higher than those of PVA/PVP blends. The maximum dielectric constant and the dielectric loss were 125 (10−2 Hz, 150 °C) and 1.1 (10−2 Hz, 70 °C), respectively, for PVA/PVP/SiO2 nanocomposites with 25 wt % SiO2 content. These results enable the preparation of dielectric nanocomposites using a facile solution-casting method that exhibit the desirable dielectric performance for flexible organic electronics. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44427. [ABSTRACT FROM AUTHOR]

Polyvinyl alcohol/potassium chromate (K2CrO4) composite films were prepared by solution casting technique using distilled water as a solvent, and were further investigated using Fourier transform infrared spectroscopy, ultraviolet–visible spectroscopy, X-ray diffraction, thermogravimetric analysis, optical microscopy, scanning electron microscopy, and dielectric measurements. Microscopic studies reveal that K2CrO4was homogenously mixed with polyvinyl alcohol matrix due to interfacial interaction between polyvinyl alcohol and K2CrO4. The composite films showed very high dielectric constant and relatively low dielectric loss. Hence, such composite materials with improved dielectric properties could be useful for fabrication of electrical charge storage device. [ABSTRACT FROM AUTHOR]

Polyvinyl alcohol/yttrium oxide (PVA/Y 2 O 3 ) nanocomposite films with five different weight ratios of PVA and Y 2 O 3 nanoparticles (NPs) were prepared using a simple solution casting method. The prepared polymer nanocomposite (PNC) films were examined using Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). FTIR spectra exhibited a strong interaction between the PVA matrix and Y 2 O 3 NPs. SEM results indicated that Y 2 O 3 NPs were properly dispersed in the PVA matrix. The thermal stability of the PVA/Y 2 O 3 nanocomposite films was found to be dependent on Y 2 O 3 NP loading (wt%) in the nanocomposite films. Furthermore, chemiresistive gas sensing properties of the PVA/Y 2 O 3 nanocomposite films were evaluated and the sensing parameters including sensing response, operating temperature, selectivity, stability, response/recovery time, and repeatability were systematically investigated based on the change in electrical resistance of the nanocomposite film in the presence of carbon dioxide (CO 2 ) gas. The maximum sensing response ( S ) of 92.72% at a concentration of 100 ppm under an optimized operating temperature of 100 °C with a fast response/recovery time of ∼15/11 s towards CO 2 gas detection was observed for the PVA/Y 2 O 3 nanocomposite film with 5 wt% loading of Y 2 O 3 NPs in the PVA matrix. The finding in this work suggest that Y 2 O 3 NPs are sufficiently fast as a CO 2 gas sensing material at a relatively low operating temperature. Moreover, the key role of the Y 2 O 3 NPs in modulating the electrical and gas sensing properties of the PVA matrix is discussed here., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (This journal is © The Royal Society of Chemistry.)

A simple solution casting technique was used to fabricate perovskite strontium titanate (SrTiO 3 )-loaded poly(vinylidenefluoride- co -hexafluoropropylene) (PVDF-HFP) nanocomposite films for efficient energy storage applications. Various microscopic and spectroscopic methods were used to study the characteristics of the polymer nanocomposite films, like Fourier transform infrared spectroscopy (FTIR), X-ray diffraction technique (XRD), field emission scanning electron microscopy (FESEM), ultraviolet-visible spectroscopy, thermogravimetric analysis, and mechanical tensile test (stress vs strain). The FTIR, XRD, and FESEM analyses confirmed the incorporation and proper dispersion of SrTiO 3 nanoparticles in the PVDF-HFP polymer matrix. An improvement in the optical, thermal, and mechanical behavior of the nanocomposite film was observed compared to the pure polymer. The values of dielectric constant, loss tangent, and AC conductivity of pure PVDF-HFP polymer and PVDF-HFP/SrTiO 3 nanocomposites (2, 6, and 10 wt % SrTiO 3 loadings) were analyzed in a temperature and frequency span of 30-150 °C and 1-100 kHz, respectively. To better understand the electrical properties of the materials, Nyquist plots were generated, and their related circuit designs were fitted. The 2 wt % SrTiO 3 loaded nanocomposite exhibited the highest dielectric enhancement and AC conductivity compared to higher filler-loaded nanocomposites. This exceptional dielectric enhancement at very small filler loading is beneficial for commercialization and economically viable for real-time applications.

Removing decolorizing acid blue 113 (AB113) dye from textile wastewater is challenging due to its high stability and resistance to removal. In this study, we used an artificial neural network (ANN) model to estimate the effect of five different variables on AB113 dye removal in the sonophotocatalytic process. The five variables considered were reaction time (5-25 min), pH (3-11), ZnO dosage (0.2-1.0 g/L), ultrasonic power (100-300 W/L), and persulphate dosage (0.2-3 mmol/L). The most effective model had a 5-7-1 architecture, with an average deviation of 0.44 and R 2 of 0.99. A sensitivity analysis was used to analyze the impact of different process variables on removal efficiency and to identify the most effective variable settings for maximum dye removal. Then, an imaginary sonophotocatalytic system was created to measure the quantitative impact of other process parameters on AB113 dye removal. The optimum process parameters for maximum AB 113 removal were identified as 6.2 pH, 25 min reaction time, 300 W/L ultrasonic power, 1.0 g/L ZnO dosage, and 2.54 mmol/L persulfate dosage. The model created was able to identify trends in dye removal and can contribute to future experiments., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Nickel oxide (NiO) nanoparticles (NPs) and graphene quantum dots (GQDs) reinforced polyvinyl alcohol (PVA) nanocomposite films were prepared using a solution casting technique. The physicochemical characteristics of PVA/NiO/GQDs (PNG) nanocomposite films were studied using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and field emission scanning electron microscopy (FESEM). The obtained PNG nanocomposite films showed good mechanical flexibility and improved tensile strength. The influence of nanofiller concentrations on PNG nanocomposite film. The obtained results demonstrate an increase in the activation energy (Ea) up to PNG3 upon increasing the GQDs concentration and thereafter, its decreases. The fundamental interactions of the constituents of PNG nanocomposite film were investigated using density functional theory (DFT). This study on electronic structure reveals that the PVA model indirectly interacts with GQDs through the NiO model. This configuration is favoured in terms of interaction energy (-78 kJ/mol) compared to the one in which PVA interacts directly with the GQDs model., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Over the last few decades, various volatile organic compounds (VOCs) have been widely used in the processing of building materials and this practice adversely affected the environment i.e. both indoor and outdoor air quality. A cost-effective solution for detecting a wide range of VOCs by sensing approaches includes chemiresistive, optical and electrochemical techniques. Room temperature (RT) chemiresistive gas sensors are next-generation technologies desirable for self-powered or battery-powered instruments utilized in monitoring emissions that are associated with indoor/outdoor air pollution and industrial processes. In this review, a state-of-the-art overview of chemiresistive gas sensors is provided based on their attractive analytical characteristics such as high sensitivity, selectivity, reproducibility, rapid assay time and low fabrication cost. The review mainly discusses the recent advancement and advantages of graphene oxide (GO) nanocomposites-based chemiresistive gas sensors and various factors affecting their sensing performance at RT. Besides, the sensing mechanisms of GO nanocomposites-based chemiresistive gas sensors derived using metals, transition metal oxides (TMOs) and polymers were discussed. Finally, the challenges and future perspectives of GO nanocomposites-based RT chemiresistive gas sensors are addressed., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

The present work reports the preparation of polyvinyl formal (PVF)/Titanium dioxide (TiO 2 ) nanocomposite films using a solution casting method followed by the characterization of the synthesized PVF/TiO 2 nanocomposite films using various analytical techniques namely FTIR, XRD, UV-vis, SEM and TGA analysis. The results obtained from different analyses confirmed that the TiO 2 NPs was fine dispersed within the PVF matrix and there exists well compatibility among the polymer matrix and the nanofiller. The pristine TiO 2 NPs based fabricated chemiresistive sensor exhibits the maximum sensitivity of 50.25% at 370 °C where as PVF/TiO 2 nanocomposite sensor showed the enhanced sensitivity of 83.75% at a relatively low operating temperature of 150 °C towards 600 ppm sulfur dioxide (SO 2 ) gas. The 25 wt% PVF/TiO 2 nanocomposite film sensor exhibited good sensitivity (∼83.75%), selectivity, rapid response time (66 s)/recovery time (107 s), and long-term stability of 60 days for SO 2 gas detection. The fabricated PVF/TiO 2 nanocomposite film sensors in our work possesses the advantages of low power consumption, cost-effective, and distinguished sensing abilities for SO 2 detection makes it possible for potential applications. Thus, the fabricated chemiresistive sensors based on TiO 2 NPs reinforced PVF nanocomposites films are evaluated and experimental results to show an excellent behavior towards SO 2 gas detection for industrial processes control and environmental monitoring applications., Competing Interests: Declaration of competing interest All the authors declare no conflict of interest., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Easily recyclable photocatalysts have received considerable attention for their practical application, in order to address the wastewater treatments. Here, we report efficient and magnetically recyclable ZnS-WO 3 -CoFe 2 O 4 nanohybrid prepared through wet impregnation method. The photophysical and optical properties of as-prepared photocatalysts was investigated by different spectroscopic techniques. The photocatalytic activity of as synthesized samples were assessed by the photodegradation of methylene blue (MB) dye under visible light irradiation. Amongst, ZnS-WO 3 -CoFe 2 O 4 nanohybrid exhibit higher photodegradation activity than the other bare and hybrid samples. The enhanced light absorption and lower emission intensity provide the improved photocatalytic activity of ZnS-WO 3 -CoFe 2 O 4 nanohybrid. The ZnS-WO 3 -CoFe 2 O 4 nanohybrid exhibit excellent photostability after four consecutive cycles. The ferromagnetic behavior of the hybrid sample using easily recover from the dye solution using an external bar magnet., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Polymer composites have established an excellent position among the technologically essential materials because of their wide range of applications. An enormous research interest has been devoted to zinc oxide (ZnO) based polymer nanocomposites, due to their exceptional electrical, optical, thermal, mechanical, catalytic, and biomedical properties. This article provides a review of various polymer composites consisting of ZnO nanoparticles (NPs) as reinforcements, exhibiting excellent properties for applications such as the dielectric, sensing, piezoelectric, electromagnetic shielding, thermal conductivity and energy storage. The preparation methods of such composites including solution blending, in situ polymerization, and melt intercalation are also explained. The current challenges and potential applications of these composites are provided in order to guide future progress on the development of more promising materials. Finally, a detailed summary of the current trends in the field is presented to progressively show the future prospects for the development of ZnO containing polymer nanocomposite materials., (Copyright © 2019 Elsevier B.V. All rights reserved.)