scholarly journals Optical Investigation of PVA/PbTiO3 Composite for UV-Protective Approach Applications

2021 ◽  
Vol 11 (1) ◽  
pp. 4
Author(s):  
Asmaa. S. El-Deeb ◽  
Marwa. M. Abdel Kader ◽  
Gamal. M. Nasr ◽  
Mona. A. Ahmed ◽  
Eman O. Taha

Samples of a new-fangled polymer of poly (Vinyl Alcohol) (PVA) doped with various concentrations of Lead (II) Titanate (PbTiO3, PT) were prepared using the casting method. The prepared samples were identified by Attenuated Total Reflection–Fourier Transform Infrared (ATR-FTIR). Peaks characteristic of PVA at 3280, 2917, 1690, 1425, 1324, 1081, and 839 cm−1 appeared; a peak indicating the presence of PbTiO3 also appeared at 713 cm−1. The interaction between PVA and PbTiO3 was confirmed by observing the change in IR absorption intensity. Optical properties in the UV-Vis range were investigated using an Ultraviolet Visible technique (UV-Vis). An enhancement in absorption capacity by the increasing PbTiO3 concentration was observed. Optical properties such as band gap energy, Urbach energy, and extinction coefficient indicate that addition of PbTiO3 into the PVA polymer induced variance in internal states by increasing the ratio of PbTiO3. Obtaining a UV-protective material derived from a PVA/PbTiO3 composite is the aim of this paper.

2011 ◽  
Vol 335-336 ◽  
pp. 32-35
Author(s):  
Fang Wei Xie ◽  
Pei Li ◽  
Li Qiang Zhang ◽  
Xiao Liang Wang ◽  
Huan Wang ◽  
...  

In-doped ZnO thin film has been found as one of the most promising materials in the optoelectronics, but its optical properties are rarely reported. We calculated optical band gaps and optical properties of Zn1-xInxO with different In doping by using first-principle. The results reveal that the lattice constants of Zn1-xInxO increase linearly with the doping increasing and Zn1-xInxO (x=0.125, x=0.25) crystal comes to be degenerate semiconductor with band gap reduced. The imaginary part of dielectric function has an increasing trend and the absorption capacity significantly increases in ultraviolet (UV) range after doping. Also there is an obvious red-shift in the absorption spectrum. The reflectivity and energy loss spectrum were investigated, too. The results can provide a theoretical reference for finding appropriate UV protective material.


2020 ◽  
Vol 92 (2) ◽  
pp. 20402
Author(s):  
Kaoutar Benthami ◽  
Mai ME. Barakat ◽  
Samir A. Nouh

Nanocomposite (NCP) films of polycarbonate-polybutylene terephthalate (PC-PBT) blend as a host material to Cr2O3 and CdS nanoparticles (NPs) were fabricated by both thermolysis and casting techniques. Samples from the PC-PBT/Cr2O3 and PC-PBT/CdS NCPs were irradiated using different doses (20–110 kGy) of γ radiation. The induced modifications in the optical properties of the γ irradiated NCPs have been studied as a function of γ dose using UV Vis spectroscopy and CIE color difference method. Optical dielectric loss and Tauc's model were used to estimate the optical band gaps of the NCP films and to identify the types of electronic transition. The value of optical band gap energy of PC-PBT/Cr2O3 NCP was reduced from 3.23 to 3.06 upon γ irradiation up to 110 kGy, while it decreased from 4.26 to 4.14 eV for PC-PBT/CdS NCP, indicating the growth of disordered phase in both NCPs. This was accompanied by a rise in the refractive index for both the PC-PBT/Cr2O3 and PC-PBT/CdS NCP films, leading to an enhancement in their isotropic nature. The Cr2O3 NPs were found to be more effective in changing the band gap energy and refractive index due to the presence of excess oxygen atoms that help with the oxygen atoms of the carbonyl group in increasing the chance of covalent bonds formation between the NPs and the PC-PBT blend. Moreover, the color intensity, ΔE has been computed; results show that both the two synthesized NCPs have a response to color alteration by γ irradiation, but the PC-PBT/Cr2O3 has a more response since the values of ΔE achieved a significant color difference >5 which is an acceptable match in commercial reproduction on printing presses. According to the resulting enhancement in the optical characteristics of the developed NCPs, they can be a suitable candidate as activate materials in optoelectronic devices, or shielding sheets for solar cells.


Author(s):  
Atefeh Nazari Setayesh ◽  
Hassan Sedghi

Background: In this work, CdS thin films were synthesized by sol-gel method (spin coating technique) on glass substrates to investigate the optical behavior of the film. Methods: Different substrate spin coating speeds of 2400, 3000, 3600 rpm and different Ni dopant concentrations of 0 wt.%, 2.5 wt.%, 5 wt.%) were investigated. The optical properties of thin films such as refraction index, extinction coefficient, dielectric constant and optical band gap energy of the layers were discussed using spectroscopic ellipsometry method in the wavelength range of 300 to 900 nm. Results: It can be deduced that substrate rotation speed and dopant concentration has influenced the optical properties of thin films. By decreasing rotation speed of the substrate which results in films with more thicknesses, more optical interferences were appeared in the results. Conclusion: The samples doped with Ni comparing to pure ones have had more optical band gap energy.


2013 ◽  
Vol 16 (1) ◽  
pp. 17-20 ◽  
Author(s):  
Mustafa Abdallh ◽  
◽  
Osama Hamood ◽  
Emad Yousif ◽  
◽  
...  

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1570
Author(s):  
Shujahadeen B. Aziz ◽  
Elham M. A. Dannoun ◽  
Dana A. Tahir ◽  
Sarkawt A. Hussen ◽  
Rebar T. Abdulwahid ◽  
...  

In the current study, polymer nanocomposites (NCPs) based on poly (vinyl alcohol) (PVA) with altered refractive index and absorption edge were synthesized by means of a solution cast technique. The characterization techniques of UV–Vis spectroscopy and XRD were used to inspect the structural and optical properties of the prepared films. The XRD patterns of the doped samples have shown clear amendments in the structural properties of the PVA host polymer. Various optical parameters were studied to get more insights about the influence of CeO2 on optical properties of PVA. On the insertion of CeO2 nanoparticles (NPs) into the PVA matrix, the absorption edge was found to move to reduced photon energy sides. It was concluded that the CeO2 nanoparticles can be used to tune the refractive index (n) of the host polymer, and it reached up to 1.93 for 7 wt.% of CeO2 content. A detailed study of the bandgap (BG) was conducted using two approaches. The outcomes have confirmed the impact of the nanofiller on the BG reduction of the host polymer. The results of the optical BG study highlighted that it is crucial to address the ɛ” parameter during the BG analysis, and it is considered as a useful tool to specify the type of electronic transitions. Finally, the dispersion region of n is conferred in terms of the Wemple–DiDomenico single oscillator model.


Coatings ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 882
Author(s):  
Yuechan Li ◽  
Yongli Li ◽  
An Xie

Doping impurity into ZnO is an effective and powerful technique to tailor structures and enhance its optical properties. In this work, Zn1−xMgxO and Zn1−x−yMgxByO nanoparticles (x = 0, 0.1, 0.2, 0.3, 0.4; y = 0, 0.02, 0.04) were synthesized via one-pot method. It shows that the Mg and B dopants has great influence on crystallinity and surface morphology of ZnO nanoparticles, without changing the wurtzite structure of ZnO. The band structure study indicates that the competition of Conductive Band (CB) shift, Burstein–Moss (B-M) shift and Shrinkage effect will cause the band gap energy change in ZnO.


2014 ◽  
Vol 2014 ◽  
pp. 1-4 ◽  
Author(s):  
K. R. Nemade ◽  
S. A. Waghuley

Solvent mixed spray pyrolysis technique has attracted a global interest in the synthesis of nanomaterials since reactions can be run in liquid state without further heating. Magnesium oxide (MgO) is a category of the practical semiconductor metal oxides, which is extensively used as catalyst and optical material. In the present study, MgO nanoparticles were successfully synthesized using a solvent mixed spray pyrolysis. The X-ray diffraction pattern confirmed the formation of MgO phase with an excellent crystalline structure. Debye-Scherrer equation is used for the determination of particle size, which was found to be 9.2 nm. Tunneling electron microscope analysis indicated that the as-synthesized particles are nanoparticles with an average particle size of 9 nm. Meanwhile, the ultraviolet-visible spectroscopy of the resulting product was evaluated to study its optical property via measurement of the band gap energy value.


2021 ◽  
Vol 19 (4) ◽  
pp. 27-37
Author(s):  
Doaa E. Al-Kateb ◽  
Ali R. Abdulridha

In this study preparing and investigating of the (PVA/PVP:Sr2NO3) nanocomposites films by using casting method with different concentration of Sr2NO3 as (0, 1, 3, 5, and 7 wt. %). Optical properties obtained by UV-Vis spectrometer, OM and FTIR spectra have been revealed in this study, the absorbance increased by increasing of Sr2NO3 nanoparticles concentrations, the energy-gap (allowed and forbidden) transitions decreased by increasing of the nanoparticles concentration.


2016 ◽  
Vol 64 (2) ◽  
pp. 157-161
Author(s):  
M Alauddin ◽  
MM Islam ◽  
MA Aziz

The structural, spectroscopic (IR, NMR and UV-Vis), electronic and optical properties of monohydrated adenine (monohydrated 6-aminopurine, C5H5N5.H2O) are investigated theoretically using DFT/B3LYP level of theory. Three minimum energy structures have been identified for monohydrated of adenine where H2O molecule is doubly hydrogen bonded with adenine.1H NMR analysis shows that the protons which are hydrogen bonded become deshielded and chemical shift moves to the higher frequency region.Five IR active mode of vibrations were found at 3108, 3295, 3665, 3676 and 3719 cm-1 which are assigned as bonded -OH vibration of H2O, Bonded -NH vibration of NH2, Free -NH vibration of adenine (9 N), Free -NH vibration of NH2, Free -OH vibration of H2O, respectively and agree well with the available experimental results. The investigation of electronic properties shows that the HOMO-LUMO band gap energy of monohydrated adenine at B3LYP level is 5.15 eV. The major electronic transition (from HOMO to LUMO (83%) (π→π*)) occurs at 258 nm (4.80 eV) with a minor transition at 237 nm (5.23 eV). Theoretically it is observed that the HOMO-LUMO band gap energy is for monohydrated adenine is lower than that of adenine. Dhaka Univ. J. Sci. 64(2): 157-161, 2016 (July)


2021 ◽  
Vol 12 (1) ◽  
pp. 170-179

ZnO-Polystyrene nanoparticles doped with Fe2O3 were prepared by the casting method. Both Ed and Eo were calculated. εL and N/m* increase with filler concentrations for these samples. On the other hand, both M-1, M-3, decreased with increasing filler. The filler concentrations affected on determined values of both of ε\ and ε\\. These values increase with filler, and also the same result was achieved for both σ1 and σ2, which also increases with filler. The relation between VELF and SELF was determined. χ(1) increases with increasing filler ratio. n2, χ(3), βc, were determined theoretically. The electrical susceptibility χe and relative permittivity εr increase with the increase of filler concentration as a result of increasing electron mobility.


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