Search

The polyaniline (PANI) and PANI/carbon nanotubes (CNT)/graphene oxide (GO) thin film were prepared in indium tin oxide coated glass plate by spin coating method. The molecular structure and physical properties of PANI and its hybrid nanocomposites were characterized by UV–Vis spectra, field emission scanning electron microscope (FE-SEM) and atomic force microscopy (AFM). UV–Vis spectra show the agreement with formation of π–π* electron interaction between PANI and CNT/GO. This interaction causes the decrease of bandgap due to confinement of the electrons and holes. The FE-SEM and AFM image of hybrid nanocomposites is different than PANI due to globular morphologies in the presence of CNT and GO. The surface free energy of PANI and hybrid nanocomposites thin films was analyzed by measuring contact angles. The dielectric permittivity and tangential loss (tan δ) of hybrid nanocomposites with different frequency were investigated at room temperature. The incorporation of CNT and GO in PANI matrix possesses high dielectric constant, low dielectric loss and high energy density. The excellent C3H6O gas sensing performance of PANI/CNT/GO hybrid nanocomposites thin film may be attributed to more oxygen vacancies and narrower bandgap. The response of PANI/CNT/GO sensor was four times better than PANI sensor with the recovery time of 506 s. [ABSTRACT FROM AUTHOR]

The thin film of nanocomposites was prepared by solution casting methods and characterized by UV–Vis spectra, Raman spectra and scanning electron microscopy (SEM). The optical band gap was determined by Tau plots. The band gap of PVDF was determined with and without BaZrO3 nanoparticles. It could be seen that the band gap decreases from 4.98 to 3.32 eV in the presence of BaZrO3 nanoparticles in PVDF matrix. The Raman study identifies the interacting species with PVDF due to structural change by the addition of BaZrO3 nanoparticles. This helps to understand the potential of new nanocomposites. The structural changes were analyzed by crystallinity, nature of bonds, phase transition from G to B-phase, etc. SEM images represent the change in spherulitic morphology of PVDF by incorporation of BaZrO3 nanoparticles. SEM images are presented the aggregation of BaZrO3 nanoparticles in PVDF matrix causes the generation of larger particles in PVDF chain. DSC supports the crystallization of PVDF nanocomposites upon heating due to the rearrangement of PVDF structure in the presence of BaZrO3 nanoparticles. It is observed that BaZrO3 nanoparticles enrich the structural, thermal and piezoelectric properties due to the change in spherulitic morphology, which creates a large number of micro- to nano-sized pores, increases the β-phase content of the PVDF. [ABSTRACT FROM AUTHOR]

The polymer nanocomposites samples of the poly (methyl methacrylate) (PMMA)—poly (vinylidene fluoride–trifluoroethylene) P(VDF–TrFE) with graphene oxide (GO) were prepared by solution casting method. The impact of GO on electroactive polar β-phase of PMMA + P(VDF–TrFE) was investigated through the Fourier transform infrared spectroscopy (FTIR) and atomic force microscopy. The mechanical properties of nanocomposites samples have been investigated by measurement of microhardness. The value of microhardness and indentation depends on applied load on samples. The experimental result suggests that mechanical properties of samples decrease in presence of GO due to decrease in uniaxial orientation or agglomeration of GO. Surface characteristics such as surface free energy, interfacial free energy and hydrophobicity were determined by measuring the contact angle. [ABSTRACT FROM AUTHOR]

BaZrO3 and BaTiO3 nanofillers were incorporated in pristine PVDF and pristine PVC blend matrix separately to prepare blend nanocomposites using the solution casting technique. The mass ratios of PVDF/PVC/BaTiO3 were chosen to be 80/16/4. The structure morphology of nanocomposites was analyzed by Fourier transform infrared spectroscopy (FTIR), atomic force microscopy (AFM), and X-ray diffraction. The FTIR, AFM, XRD and pyroelectric results indicate the strong interaction between the nanofiller and PVDF/PVC blend matrix. The nanocomposite exhibits a high pyroelectric coefficient due to proper dispersion of nanofillers. The maximum piezoelectric coefficients (d33) were 39, 88, 79.72, 112pC N−1 for pristine PVC, pristine PVDF, PVDF/PVC/BaZrO3 and PVDF/PVC/BaTiO3 blend nanocomposites, respectively. The remnant polarization of blend nanocomposites is also measured by P–E loop. P–E loop shows that the polarization of the blend nanocomposites increases under influence of nanofiller. The pyroelectric coefficient for PVDF/PVC/nanofiller blend nanocomposite is very sensitive in the temperature range of 30 to 180 °C and greater than PVC (i.e. 351 µC m−2 K−1 > 15 µC m−2 K−1). [ABSTRACT FROM AUTHOR]

XRD peaks demonstrate the interaction of nanoparticles with polymer matrix. It is evident from the dielectric data that observed change in dielectric parameters would result from appropriate changes in chain mobility due to nanoparticles-polymer interactions. FT-IR spectra represent the significant changes in intensity, shape and position of the different vibrational bands corresponding to -OH stretching, C-O-C stretching, C-H stretching and C-O-C in C-H stretching modes occur as a result of the incorporation of BaZrO3 nanofiller. Thermally stimulated discharge current (TSDC) and transient discharging current study presented the dipolar and interfacial type of relaxations. [ABSTRACT FROM AUTHOR]

Nanocomposite thin films containing PVDF and BaZrO have been prepared by solution cast technique. The thin films of different mass% of BaZrO nanoparticles were prepared. Heating rate and BaZrO-concentration-dependent pyroelectric properties have been investigated. Pyroelectric effect is only observable during the period in which the temperature changes. The nanofiller improve the surface and bulk structure of (PVDF) and could be able to improve dipole concentration. The BaZrO-enhanced formation of crystalline β phase in PVDF is due to strong interaction between the -C=O groups in BaZrO and the -CF groups in PVDF, and the BaZrO-induced nanostructures of amorphous and crystalline phases. This nanostructure enhances the pyroelectric activity of PVDF. [ABSTRACT FROM AUTHOR]

Polycarbonate (PC)/Zinc oxide (ZnO) nanocomposite films were prepared by a solution mixing method and irradiated by Swift heavy ion at various ions fluences ranging from 1 × 10 to 3 × 10. The surface morphological, structural, and thermal properties of untreated and irradiated PC/ZnO nanocomposite films were investigated by various characterizations techniques such as X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and differential scanning calorimetry, Thermogravimetric (TG) and Thermally stimulated discharge current (TSDC). The XRD pattern reveals that the average crystallite size and percentage of crystallinity decreases with increase of ion fluences. TSDC measurement is an evidence of different type of relaxation process. The activation energy released charge and charge carrier mobility for α-relaxation peak decreases, while relaxation time and peak current increase. TG measurement shows thermal stability and mass loss decreases with ions fluences. FTIR spectra reveal the position of different bonds in PC and nanocomposite films. The glass transition temperature of nanocomposites is observed to be decreases with ion fluences. [ABSTRACT FROM AUTHOR]

β-phase polyvinylidene fluoride (PVDF)-BaTiO nanocomposite samples have been prepared by solution mixing method. XRD data represent that the crystallinity of PVDF decreases with increase in loading level of BaTiO nanoparticles. DSC curve represents that the melting point of PVDF is lightly affected by loading concentration of BaTiO. The morphology and microstructure of PVDF and PVDF embedded by BaTiO nanofillers were investigated by using inverted contrast microscopy (ICM) and scanning electron microscopy (SEM). FTIR interferrometry is proven that PVDF and BaTiO are not chemically interacting; therefore, interaction of BaTiO is van der Waals type of interaction. The thermally stimulated discharge current (TSDC) of PVDF and PVDF-BaTiO nanocomposites sample was characterized by single peak. The observed TSDC peak is discussed on the basis of dipolar and interfacial polarization. [ABSTRACT FROM AUTHOR]

The structural and thermal behavior of PVDF/ZnO nanocomposites have been investigated by employing scanning electron microscopy (SEM),TEM, DSC, powder X-ray diffraction (XRD), thermally stimulated discharge current (TSDC), and transient current techniques. SEM/TEM observation indicated the homogeneous dispersion of functionalized ZnO nanoparticles throughout PVDF matrix. DSC shows that the crystallinity is influenced by the presence of ZnO nanoparticles in the PVDF matrix because the filler acts as efficient nucleating agent to facilitate PVDF crystallization. DSC results indicated the enhancement of the glass transition temperature ( T), melting temperature ( T) and crystallization temperature ( T) of nanocomposites compared to pristine PVDF. XRD shows that the full-width at half maximum decreases with increasing ZnO content, which is attributed to the improvement in crystallinity. The incorporation of ZnO nanoparticles influences the modification of polarization process in PVDF as observed by means of TSDC and transient current study. [ABSTRACT FROM AUTHOR]

Polymer nanocomposite thin film of polysulfone with different concentration of ZnO was prepared by solution grown technique. This paper presents a study on the structural and thermal properties of ZnO filled Polysulfone (PSF) nanocomposites. The structural morphology of the resulting nanocomposites was investigated by X-ray diffraction (XRD), Scanning electron microcopy (SEM), and Atomic force microscopy (AFM). Thermal properties of PSF nanocomposites samples were investigated by Differential thermal analysis, Thermal gravimetric, and Differential thermal gravimetric. Structural result shows that the ZnO nanofiller with different mass% in polymer matrix cause the significant variation of lattice spacing, crystallite size, and percentage crystallinity. XRD result shows that the amorphous behavior of PSF (Pristine) is increasing with incorporation of ZnO nanoparticle in PSF matrix. The SEM and AFM images show the change in structural morphology of PSF due to incorporation of ZnO nanoparticles. The thermal analysis result shows that the significant thermal degradation of polysulfone nanocomposites due to catalytic behavior of ZnO nanoparticles. [ABSTRACT FROM AUTHOR]

The optical properties have been investigated using EDX, UV-Visible spectroscopy and Raman spectroscopy. The nanocomposite formation was confirmed using EDX as well as UV-Visible absorption spectroscopy. Raman study confirms the β phase of PVDF. The UV-Vis spectroscopy accounts for a significant continuous decline in optical band gap and optical activation energy, while increase in refractive index with ZnO nanoparticles incorporation. The results imply that the effectiveness in shielding of UV radiation is due to absorption capacity of ZnO nanoparticles incorporated in PVDF. The increase of absorption in the UV-region of the spectrum is due to the excitations of donor level electrons to the conduction band at these energies. This decrease of band gap may be attributed by presence of unstructured bulk defects. The optical properties of nanocomposite thin films were shown to depend on ZnO content and possessed the most optimal optical properties. [ABSTRACT FROM AUTHOR]