Advanced Technology and New Material Institute

Alexandria, Egypt

Advanced Technology and New Material Institute

Alexandria, Egypt
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Taha A.,Ain Shams University | Farag A.A.M.,University of Science and Arts of Iran | Farag A.A.M.,Ain Shams University | Adly O.M.I.,Ain Shams University | And 3 more authors.
Journal of Molecular Structure | Year: 2017

Metal complexes of Ni(II) and Cu(II) with a new Schiff base, 2-benzylidene-3-hydroxy -1-(5,6-diphenyl-1,2,4-triazine-3-yl)hydrazine (HBDHT) have been synthesized and characterized by elemental analysis and spectroscopic methods. The results adopt octahedral and square planar structures for Ni(II) and Cu(II) complexes, respectively with the formula, [Ni(BDHT)(NO3)(H2O)2)]·H2O and [Cu(BDHT)(H2O)](NO3)·H2O. The emission spectra arising from S1 state is assigned to π∗ →π and LUMO→HOMO transition character for investigated molecules. Structural parameters of the synthesized compounds were calculated on the basis of DFT level implemented in the Gaussian 09 program. The size of the prepared nano particles was obtained by scanning electron microscopy (SEM) and particle size analyzer. Analysis of the absorption coefficient near the fundamental absorption edge emphasizes two indirect allowed transitions n → π∗ and π → π∗ with energy gaps of 1.1 and 2.55 eV. The forward bias current of the prepared heterojunction shows diode-like behavior with appreciable rectification characteristics. The extracted heterojunction parameters show light dependence which supporting the achievability for the optical sensor in several optoelectronic applications. © 2017 Elsevier B.V.


Taha A.,Ain Shams University | Farag A.A.M.,University of Science and Arts of Iran | Farag A.A.M.,Ain Shams University | Adly O.M.I.,Ain Shams University | And 3 more authors.
Journal of Molecular Structure | Year: 2017

A newly Schiff base,2-benzylidene-3-hydroxy-1-(5,6-diphenyl-1,2,4-triazine-3-yl)hydrazine] (HBDHT) was synthesized and characterized on the basis of micro-analytical and spectroscopic studies. Basic parameters of the combined compound HBDHT were ascertained on the premise of DFT level actualized on Gaussian 09. Thin films of HBDHT were successfully prepared by spin coating technique and confirmed by atomic force microscopy (AFM). The optical attributes of the studied films were considered utilizing spectrophotometric estimations in a wide spectral range of 200–2500 nm. Some important optical parameters such as extinction index, refractive index, dispersion energy, oscillator energy and high-frequency dielectric constant were extracted. Analysis of the absorption coefficient near the fundamental absorption edge confirms an indirectly allowed transition with an energy gap of 1.7eV. The refractive index dispersion was estimated on basis of single oscillator model expressed by Wemple–Didomenico. Current–voltage (I–V) characteristics were studied in dark and under illumination of 100 mW/cm2 to clarify the sensitivity to light. Moreover, the photo-transient properties were also investigated to confirm that the prepared heterojunction based HBDHT can be operated as a photodiode. © 2017 Elsevier B.V.


Farag A.A.M.,Ain Shams University | Farag A.A.M.,Al Jouf University | Abdel Rafea M.,Advanced Technology and New Material Institute | Abdel Rafea M.,Imam Muhammad ibn Saud Islamic University | And 3 more authors.
Journal of Alloys and Compounds | Year: 2015

Low cost dip coating technique was successfully used to deposit highly uniform and good adhesive nanocrystalline Zn1-xCdxS (0 ≤ x ≤ 0.9) thin films. The surface morphology and crystalline structural characteristics of Zn1-xCdxS were achieved by using atomic force microscopy (AFM) and transmission electron microscopy (TEM), respectively. Transmission spectra show red shifting of absorption edge as the Cd content increased. The optical constants were accurately determined by using reflectance and transmittance spectra. The effect of Cd-content on refractive index, extinction index and other optical dispersion parameters were also investigated. The dispersion of the refractive index was discussed in terms of single oscillator model. In addition, the ratio of free carrier concentration to its effective mass was estimated. The calculated value of oscillator energy Eo obeys the empirical relation (Eo ≈ 2 Eg), obtained from single oscillator model. Small magnitude of optical electronegativity (χ∗) for Zn1-xCdxS (0 ≤ x ≤ 0.9) thin films and relatively high refractive index can be attributed to covalent nature, in agreement with β value, obtained from dispersion energy analysis. Moreover, molar polarizability and third-order nonlinear optical susceptibility were also considered. © 2014 Elsevier B.V. All rights reserved.


Ibrahim M.A.,Ain Shams University | Farag A.A.M.,University of Science and Arts of Iran | Farag A.A.M.,Ain Shams University | Roushdy N.,Advanced Technology and New Material Institute | El-Gohary N.M.,Ain Shams University
Journal of Molecular Structure | Year: 2016

Condensation reaction of 6-bromochromone-3-carboxaldehyde (1) with dimedone afforded 9-(6-bromo-4-oxo-4H-chromen-3-yl)-3,4,6,7-tetrahydro-3,3,6,6-tetramethyl-2H-xanthene-1,8-(5H,9H)-dione (3, BOCTTX). Structure of BOCTTX was deduced based on its correct elemental analysis and spectral data (IR, 1H NMR, 13C NMR and mass spectra). Thin films of BOCTTX were prepared in this study by using spin coating technique. X-ray diffraction, scanning electron microscope analysis were studied for study the crystal and morphology characterization of BOCTTX. The results indicate that BOCTTX has a polycrystalline nature with monoclinic structure. From differential scanning calorimetry, BOCTTX is found to be thermally stable up to 583 K and the chemical structure plays an important role in the thermal decomposition process. The optical absorption of the film was studied in the UV-Vis spectral range and the value of two allowed energy gaps of 2.2 and 3.3 eV. Current-voltage characteristics of BOCTTX based devices were studied in dark and under various illumination intensities in the range 20-100 mW/cm2. Electrical and photoelectrical parameters were studied as a function of light intensity. The obtained results exhibits photoconductivity cauterization and suggest that the diode can be used as a photodiode in optoelectronic sensor application. © 2015 Elsevier B.V. All rights reserved.


Farag A.A.M.,Ain Shams University | Farag A.A.M.,University of Science and Arts of Iran | Ibrahim M.A.,Ain Shams University | El-Gohary N.M.,Ain Shams University | Roushdy N.,Advanced Technology and New Material Institute
Arabian Journal of Chemistry | Year: 2016

A new derivative of heteroannulated chromeno[2,3-b]pyridine identified as 5-ethyl-7H,9H-chromeno[3″,2″:5',6']pyrido[3',2':5,6]pyrano[3,2-c]quinoline-6(5H),7,9-trione (3) (ECPPQT) was easily and efficiently synthesized from DBU catalyzed condensation reaction of 2-aminochromone-3-carboxaldehyde (1) with 6-ethyl-4-hydroxy-2H-pyrano[3,2-c]quinoline-2,5(6H)-dione (2). Structure of ECPPQT was deduced based on its correct elemental analysis and spectral data (IR, 1H NMR, and mass spectra). The X-ray diffraction patterns of TCVA in powder form show that there are several peaks with different intensities, indicating that the material has a polycrystalline nature. Optical absorption properties of ECPPQT thin films in near ultraviolet, visible and near infrared spectral regions showed characteristic absorption peaks. Optical absorptions were used to determine the characteristic band transitions in the range of 200-1100nm. Two direct band gaps were calculated and found to be 1.85 and 3.30eV for the optical and transport energy gaps, respectively. The ECPPQT/p-Si diode performs low photovoltaic characteristics with open circuit voltage of 330mV, short-circuit current of 37μA and fill factor of 33%. The phototransient measurements of the device indicate that the device has a good stability and quick response properties. © 2016.


Roushdy N.,Advanced Technology and New Material Institute | Farag A.A.M.,Ain Shams University | Abdel Rafea M.,Advanced Technology and New Material Institute | El-Shazly O.,Alexandria University | El-Wahidy E.F.,Alexandria University
Superlattices and Microstructures | Year: 2013

Nanocrystalline Zn1-xCdxS (0 ≤ x ≤ 0.9) thin films were prepared by dip-coating method. The compositional analyses were made by the energy dispersive X-ray technique (EDX). X-ray diffraction analyses (XRD) of the prepared samples were performed to investigate the crystalline structure and determine the main structural parameters using Williamson-Hall (W-H) model. The surface morphology and crystalline structure of nanocrystalline Zn1-xCdxS thin films were studied using the scanning electron microscopy (SEM) and transmission electron microscopy (TEM), respectively. The estimated average crystallite size of Zn1-xCdxS by W-H analysis were compared with TEM results. It is found that the average crystallite size measured by W-H analysis is in good agreement with TEM results. The capacitance-voltage (C-V) characteristics of n-Zn1-xCdxS/p-Si heterojunction were measured at different temperatures ranging from 300 to 400 K under dark condition. The dependence of C-2 on V for the heterojunctions was found to be almost linear which indicates that the prepared heterojunctions are abrupt and then the essential junction parameters were obtained. The built-in potential (Vb), the donor carrier concentration (ND) and the width of the depletion region (W) were studied as a function of Cd-content. © 2013 Elsevier Ltd. All rights reserved.


Ibrahim M.A.,Ain Shams University | Farag A.A.M.,Ain Shams University | Farag A.A.M.,Al Jouf University | Roushdy N.,Advanced Technology and New Material Institute | El-Gohary N.M.,Ain Shams University
Optical Materials | Year: 2016

Friedländer condensation of 2-amino-6-chlorochromone-3-carboxaldehyde (1) with 4-hydroxycoumarin (2) under basic conditions afforded 10-chloro-6H,8H-dichromeno[2,3-b:3′,4′-e]pyridine-6,8-dione (3) (CDPD). Structure of CDPD was deduced based on its correct elemental analysis and spectral data (IR, 1H NMR, 13C NMR and mass spectra). Crystalline structure by using X-ray diffraction confirms a polycrystalline nature of the powder and films with monoclinic system. A flower-like morphology was resolved for the high magnification images of scanning electron microscopy. Three direct optical band gaps were obtained and found to be 1.17, 2.24 and 3.40 eV, respectively. A sharp single peak of photoluminescence in the visible region was observed and centered at around 683 nm as well as another two peaks at 417 and 386 nm. Rectification characteristics of the device based CDPD indicates that the device behaves as a diode. A maximum value of photosensitivity of the device was obtained under effect of 60 mW/cm2 and bias voltage of 1.25 V. The phototransient characteristics of the device confirm that the device can be operated as a photodiode. © 2015 Elsevier B.V. All rights reserved.


Rafea M.A.,Advanced Technology and New Material Institute | Farag A.A.M.,Ain Shams University | Roushdy N.,Advanced Technology and New Material Institute
Materials Research Bulletin | Year: 2012

In this work, Cu 2S nanocrystalline films have been successfully prepared using dip-coating technique. The stoichiometry and the structural characteristics of the prepared films were characterized by energy dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD), respectively. The surface morphology of the deposited Cu 2S film was studied using both the scanning electron microscopy (SEM) and the atomic force microscopy (AFM). The SEM and AFM images indicate that the prepared Cu 2S films are characterized by a well-dispersed and highly dense with spherical like-shaped aggregates of size in the nano scale. The optical absorption measurements indicate that the Cu 2S nanoparticles have a direct band gap of 2.92 eV. The dispersion and absorption parameters such as the dispersion energy, oscillating energy, real and imaginary dielectric constants and dissipation factor were calculated within a wide wavelength range of the spectrum that indicates the suitability of the deposited films as solar absorber using this technique. The dark electrical resistivity (ρ) measurements were carried out at different temperatures in the range 312-440 K. These results confirm the semiconducting characteristic of the prepared Cu 2S films. Moreover, two activation energies were obtained that indicate the presence of two dominating conduction mechanisms in these temperature ranges. The bulk electrical resistivity (ρ B) and the mean free path (l 0) of charge carriers were estimated from the resistivity-thickness dependence. The heterojunction device of n-ZnCdS/p-Cu 2S behaves good rectifying property. The photovoltaic characteristic of the heterojunction device using the current-voltage characteristic under illumination of 100 mW/cm 2 was also observed. Discussion of the obtained results and their comparison with the previous published data were also considered. © 2011 Elsevier Ltd. All rights reserved.


El-Aassar M.R.,Advanced Technology and New Material Institute | El Fawal G.F.,Advanced Technology and New Material Institute | Kamoun E.A.,Advanced Technology and New Material Institute | Fouda M.M.G.,King Saud University | Fouda M.M.G.,National Research Center of Egypt
International Journal of Biological Macromolecules | Year: 2015

In this work, hydrogel membrane composed of; kappa carrageenan (κC) and hyaluronic acid (HA) crosslinked with epichlorohydrine is produced. The optimum condition has been established based on their water absorption properties. Tensile strength (TS) and elongation (. E%) for the formed films are evaluated. The obtained films were characterized by FTIR, scanning electron microscopy (SEM) and thermal analysis. All membranes were loaded with l-carnosine as a drug model. The swelling properties and kinetics of the release of the model drug from the crosslinked hydrogel membrane were monitored in buffer medium at 37. °C. The equilibrium swelling of films showed fair dependency on the high presence of HA in the hydrogel. Moreover, the cumulative release profile increased significantly and ranged from 28% to 93%, as HA increases. SEM explored that, the porosity increased by increasing HA content; consequently, drug release into the pores and channels of the membranes is facilitated. In addition, water uptake % increased as well. A slight change in TS occurred by increasing the HA% to κC, while the highest value of strain for κC membrane was 498.38% by using 3% HA. The thermal stability of the κC/HA was higher than that of HA. © 2015 Elsevier B.V.


PubMed | National Research Center of Egypt and Advanced Technology and New Material Institute
Type: | Journal: International journal of biological macromolecules | Year: 2015

In this work, hydrogel membrane composed of; kappa carrageenan (C) and hyaluronic acid (HA) crosslinked with epichlorohydrine is produced. The optimum condition has been established based on their water absorption properties. Tensile strength (TS) and elongation (E%) for the formed films are evaluated. The obtained films were characterized by FTIR, scanning electron microscopy (SEM) and thermal analysis. All membranes were loaded with l-carnosine as a drug model. The swelling properties and kinetics of the release of the model drug from the crosslinked hydrogel membrane were monitored in buffer medium at 37C. The equilibrium swelling of films showed fair dependency on the high presence of HA in the hydrogel. Moreover, the cumulative release profile increased significantly and ranged from 28% to 93%, as HA increases. SEM explored that, the porosity increased by increasing HA content; consequently, drug release into the pores and channels of the membranes is facilitated. In addition, water uptake % increased as well. A slight change in TS occurred by increasing the HA% to C, while the highest value of strain for C membrane was 498.38% by using 3% HA. The thermal stability of the C/HA was higher than that of HA.

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