scholarly journals CuO and MWCNTs Nanoparticles Filled PVA-PVP Nanocomposites: Morphological, Optical, Thermal, Dielectric, and Electrical Characteristics

2021 ◽  
Author(s):  
Hassan A. H. Alzahrani
Keyword(s):  
Dielectric Permittivity ◽  
Energy Gap ◽  
Multiwall Carbon Nanotubes ◽  
Vinyl Pyrrolidone ◽  
Poly Vinyl Alcohol ◽  
Electrical Characteristics ◽  
Optical Energy Gap ◽  
Ac Electrical Conductivity ◽  
Applied Frequency ◽  
Solution Cast

Abstract Copper dioxide (CuO) nanoparticles and Multiwall carbon nanotubes (MWCNTs) filled poly(vinyl alcohol) (PVA) and poly(vinyl pyrrolidone) (PVP) blend matrix (50/50 wt%) based polymer nanocomposites (PNCs) (i.e., PVA/PVP:(15-x)CuO(x)MWCNTs for x=0,1,5,7.5, 10,14, and 15wt%) have been prepared employing the solution-cast method. The morphologies of these PNCs are semicrystalline, according to an X-ray diffraction investigation. The FTIR, SEM, and AFM measurements of PNCs were used to investigate the development of the miscible mix, polymer-polymer and polymer–nanoparticle interactions, and the influence of CuO and MWCNTs nanofillers on the morphology aspects on the main chain of PVA/PVP blend. The nanofiller dispersion signposting for x=14 wt% nanoloading in the PVA–PVP blend matrix significantly enhances the crystalline phase, diminishing the optical energy gap to 2.31eV. The DC conductivity values augment with the upsurge in nanofiller level for maximum x=14wt%. The dielectric and electrical characteristics of these PNCs are investigated for an applied frequency range from 1kHz to 1 MHz. The enhancement in the nanofiller level upto x=14wt% in the PVA/PVP matrix leads to the development of percolating network through the PNCs. These factors boost the dielectric permittivity values substantially, owing to the decrease in the nano-confinement phenomenon. The rise in applied frequency reduces dielectric permittivity and impedance values and enhances ac electrical conductivity. These PNCs having good dielectric and electrical characteristics can be used as frequency tunable nanodielectric material in electronic devices.

scholarly journals Effect of Wrapped Carbon Nanotubes on Optical Properties, Morphology, and Thermal Stability of Electrospun Poly(vinyl alcohol) Composite Nanofibers

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Naoual Diouri ◽  
Mimouna Baitoul ◽  
Malik Maaza
Keyword(s):  
Carbon Nanotubes ◽  
Vinyl Alcohol ◽  
Polymer Concentration ◽  
Sodium Dodecyl ◽  
Multiwall Carbon Nanotubes ◽  
Electrospun Nanofibers ◽  
Vinyl Pyrrolidone ◽  
Poly Vinyl Alcohol ◽  
Gravimetric Analysis ◽  
Sem Image

Electrospinning was used to elaborate poly(vinyl alcohol) (PVA) nanofibers in the presence of embedded multiwall carbon nanotubes (MWCNTs) in surfactant and polymer. MWCNTs were dispersed in aqueous solution using both sodium dodecyl sulfate (SDS) as surfactant and Poly(vinyl pyrrolidone) (PVP). Changing the surfactant and polymer concentration reveals that the maximum dispersion achievable is corresponding to the mass ratios MWCNTs : SDS—1 : 5 and MWCNTs : SDS : PVP—1 : 5 : 0.6 in the presence of the PVP. After the optimization of the dispersion process, the SEM image of the PVA/PVP/SDS/MWCNTs electrospun fibers presents high stability of the fibers with diameter around 224 nm. Infrared spectroscopy and thermal gravimetric analysis elucidate the type of interaction between the PVA and the coated carbon nanotube. The presence of PVP wrapped carbon nanotubes reduced slightly the onset of the degradation temperature of the electrospun nanofibers.

Effect of the structural changes on the mechanical properties of the sintered films

2016 ◽  
Vol 12 (1) ◽  
pp. 4141-4144
Author(s):  
Garima Jain
Keyword(s):  
Crystallite Size ◽  
Lattice Constant ◽  
Structural Changes ◽  
Structural Investigation ◽  
Energy Gap ◽  
Lattice Parameter ◽  
Metal Chalcogenides ◽  
Optical Energy Gap ◽  
Tin Telluride ◽  
Physical Quantities

Polycrystalline films of tin telluride were prepared by sintering technique. The structural investigation of the films with different thicknesses enables to determine lattice parameter, crystallite size and strain existing in the films. The XRD traces showed that strain was tensile in nature. The crystallite size increases with thickness while strain decreases. Higher the value of tensile strain, larger is the lattice constant. The optical energy gap shows a descending nature with increasing strain and so with the lattice constant. Such an attempt made to delve into interdependence of basic physical quantities helps to explore the properties of SnTe and utilize it as an alternative to heavy metal chalcogenides in various technological applications.  

scholarly journals Exo⇔Endo Isomerism, MEP/DFT, XRD/HSA-Interactions of 2,5-Dimethoxybenzaldehyde: Thermal, 1BNA-Docking, Optical, and TD-DFT Studies

Molecules ◽  
2020 ◽  
Vol 25 (24) ◽  
pp. 5970
Author(s):  
Nabil Al-Zaqri ◽  
Mohammed Suleiman ◽  
Anas Al-Ali ◽  
Khaled Alkanad ◽  
Karthik Kumara ◽  
...  
Keyword(s):  
Density Functional ◽  
Energy Gap ◽  
Structural Parameters ◽  
Population Analysis ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Optical Energy Gap ◽  
Functional Theory ◽  
Reactivity Descriptors ◽  
Td Dft

The exo⇔endo isomerization of 2,5-dimethoxybenzaldehyde was theoretically studied by density functional theory (DFT) to examine its favored conformers via sp2–sp2 single rotation. Both isomers were docked against 1BNA DNA to elucidate their binding ability, and the DFT-computed structural parameters results were matched with the X-ray diffraction (XRD) crystallographic parameters. XRD analysis showed that the exo-isomer was structurally favored and was also considered as the kinetically preferred isomer, while several hydrogen-bonding interactions detected in the crystal lattice by XRD were in good agreement with the Hirshfeld surface analysis calculations. The molecular electrostatic potential, Mulliken and natural population analysis charges, frontier molecular orbitals (HOMO/LUMO), and global reactivity descriptors quantum parameters were also determined at the B3LYP/6-311G(d,p) level of theory. The computed electronic calculations, i.e., TD-SCF/DFT, B3LYP-IR, NMR-DB, and GIAO-NMR, were compared to the experimental UV–Vis., optical energy gap, FTIR, and 1H-NMR, respectively. The thermal behavior of 2,5-dimethoxybenzaldehyde was also evaluated in an open atmosphere by a thermogravimetric–derivative thermogravimetric analysis, indicating its stability up to 95 °C.

Temperature Dependence of Optical Energy Gap of Gallium Selenide

2001 ◽  
Vol 8 (3-4) ◽  
pp. 251-259 ◽  
Author(s):  
M. Kepinska ◽  
M. Nowak ◽  
Z. Kovalyuk ◽  
R. Murri
Keyword(s):  
Temperature Dependence ◽  
Energy Gap ◽  
Gallium Selenide ◽  
Optical Energy Gap ◽  
Optical Energy

T(Z) diagram and optical energy gap values of (AgIn)2(1–z)(CdIn2)zTe4 alloys

1994 ◽  
Vol 144 (2) ◽  
pp. 311-316 ◽  
Author(s):  
R. Cadenas ◽  
M. Quintero ◽  
J. C. Woolley
Keyword(s):  
Energy Gap ◽  
Optical Energy Gap ◽  
Optical Energy ◽  
Gap Values

Study the Effect of the Volumetric Ratio of Alq3 on the Optical and Structural Properties of the Alq3:NPD Blend for the UV Photodetector Applications

2021 ◽  
Vol 16 (2) ◽  
pp. 281-287
Author(s):  
Alaa Y. Mahmoud
Keyword(s):  
Structural Properties ◽  
Active Layer ◽  
Energy Gap ◽  
Optical Energy Gap ◽  
Uv Photodetector ◽  
Optical Energy ◽  
Uv Photodetectors ◽  
Energy Bandgap ◽  
Xrd Patterns ◽  
Optical Energy Bandgap

The effect of the volumetric ratio of the tris(8-hydroxyquinoline) aluminum (Alq3) on its blend with the N,N'-Di [(1-naphthyl)-N,N'-diphenyl]-(1,1'-biphenyl)-4,4'-diamine (NPD) (Alq3:NPD) is investigated and optimized for the UV photodetectors fabrication. The optical and structural properties of Alq3:NPD blend with different volumetric ratios 1:1, 2:1, and 3:1 is studied in the context of the absorbance, transmittance, optical energy gap and XRD patterns. Results show that the absorbance is increased by 11% at A = 260 nm with the increase in the volumetric ratio. In contrast, the optical energy bandgap that is extrapolated from the Tauc’s plot is decreased with the increase in the volumetric ratio, and the 2:1 ratio shows the lowest energy in the UV region. In terms of the XRD investigation, the 2:1 volumetric ratio shows the highest intensity for the crystallinity peak at 36.6°. The fabricated photodetector with a different volumetric ratio of the active layer Alq3:NPD blend shows the best performance with the ratio 2:1.

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