Papers by monzir abdel-latif
Insoluble porous solid macrocyclic 1,4,7,10,13-pentaazapentadecane-3,14- dione-1-propyl-N-propyl ... more Insoluble porous solid macrocyclic 1,4,7,10,13-pentaazapentadecane-3,14- dione-1-propyl-N-propyl polysiloxane ligand systemof the general formula P-(CH2)3-NH-(CH2)3-C8H22O2N3, (where P represents [Si-O]n siloxane network) has been prepared by the reaction of macro-silane agent with tetraethyl orthosilicate. Themacro-silane agentwas prepared by the reaction of iminobis (N-2-aminoethylacetamide) ligandwith 3-iodopropyltrimethoxysilane in 1:3 molar ratio respectively. The new prepared polysiloxane system exhibits high potential for the uptake of metal ions (Fe3+, Co2+, Ni2+, Cu2+, Zn2+,Ag+, Cd2+, Hg2+ and Pb2+). Chemisorption of the metal ions by the ligand system at the optimum conditions was found in the order: Ag +i¾Pb2+ i¾ Hg2+ i¾ Cu2+ i¾ Ni2+ i¾ Fe3+ i¾ Co2+> Cd2+>Zn2+.
Journal of Liquid Chromatography & Related Technologies, 1998
ABSTRACT
Analytical Letters, 1998
Electrolytes were found to have an important influence on the cell constant in electrochemically ... more Electrolytes were found to have an important influence on the cell constant in electrochemically modulated liquid chromatography. The dependence of cell constant on electrolyte type did not reflect any relation with regard to electrolyte conductivity values. However, electrolytic species of larger ionic sizes result in significantly lower cell constants, and vice versa. It was also found that the cell constant is exponentially dependent on electrolyte concentration, with higher electrolyte concentrations resulting in decreased cell constants. When a potential ramp is applied to the working electrode, a steep change in the potential of the working electrode towards the final potential takes place directly after the application of the potential ramp. The change in the potential of the working electrode then follows an exponential decay isotherm, which depends on both electrolyte type and concentration.
Analytical Chemistry, 1988
Analytica Chimica Acta, 1989
Abstract Cetyltrimethylammonium bromide (CTAB) was used to overcome the pH mismatch of the lumino... more Abstract Cetyltrimethylammonium bromide (CTAB) was used to overcome the pH mismatch of the luminol (5-amino-2,3-dihydrophthalazine-1,4-dione ) chemiluminescence reaction when coupled to the glucose/glucose oxidase reaction at neutral pH. The results demonstrate the feasibility of conducting both reactions simultaneously and efficiently at pH 7.5–8.5. The incorporation of the CTAB micellar system in the coupled luminol/enzymatic reaction allows quantification of glucose in the 3 × 10 −7 −3 × 10 −4 M range. The relative standard deviation (RSD) for 5 replicates of 5 × 10 −5 M glucose was 3.8%. Also, hydrogen peroxide was quantified in the 1.2 × 10 −4 −2.4 × 10 −8 M range with RSD 2.6%. The micellar-mediated luminol reaction was applied successfully to the determination of glucose in blood serum. Excellent agreement with reported results by standard assays was obtained.
Analytical Letters, 1989
Abstract Aqueous sulfite and formaldehyde were quantitated in the nanomole range using the reacti... more Abstract Aqueous sulfite and formaldehyde were quantitated in the nanomole range using the reaction of 5,5′-dithiobis(2-nitrobenzoic acid), DTNB, with sulfite. Cationic micelles were used and found to greatly increase the sensitivity, bathochromically shifting the absorption spectra as well as lowering the pK of the reaction. the method was adapted to flow injection analysis, allowing more than 100 samples to be analyzed per hour with a relative standard deviation of less than 1.5% in all cases studied. the method is simple, fast and more sensitive than any available methods. the great flexibility of the choice of pH, surfactant concentration and buffer concentration contributes much to the high precision that could be achieved.
Dye-sensitized solar cells (DSSCs) were assembled using Zinc oxide (ZnO) nanoparticles as a photo... more Dye-sensitized solar cells (DSSCs) were assembled using Zinc oxide (ZnO) nanoparticles as a photoelectrode and natural dyes extracted from eight natural plants as photosensitizers. The structural properties of the synthesized ZnO nanoparticles were studied using XRD, SEM and TEM characterizations. Photovoltaic parameters such as short circuit current density Jsc, open circuit voltage Voc, fill factor FF, and overall conversion efficiency for the fabricated cells were determined under 100 mW/cm2 illumination. It was found that the DSSC fabricated with the extracted safflower dye as a sensitizer showed the best performance. Also, its performance increased with increasing the sintering temperature of the semiconductor electrode with highest performance at 400 C. Moreover, it was found that a semiconductor electrode of 7.5 m thickness yielded the highest response.
IUG Journal of Natural Studies, 2016
We report light emission from a single layer thin film device. This device is comprised of a hole... more We report light emission from a single layer thin film device. This device is comprised of a hole transporting polymer, poly(N-vinylcarbazole) (PVK) doped with a new luminescent 1,2,4-triazole derivative sandwiched between an indium tin oxide electrode (ITO) and an aluminum electrode. We have studied the current versus voltage (I-V) characteristics, the electroluminescence versus voltage (EL-V) characteristics, and the lifetime of the device. Thinner samples revealed a lower EL threshold voltage VT compared with the conventional organic light emitting diodes (OLEDs) reported in the literature. This VT increased with increasing the sample thickness.
International Journal of Renewable Energy Research, 2015
In this paper, eleven natural dyes were collected from three trees and used as photosensitizers f... more In this paper, eleven natural dyes were collected from three trees and used as photosensitizers for dye sensitized solar cells (DSSCs). The cells were fabricated using TiO 2 as a semiconducting layer deposited on transparent fluorine doped tin oxide (FTO) conductive glass using doctor blade method. The absorption spectra of the extracts were performed in the spectral range from 400 nm to 750 nm. The J-V characteristic curves of all fabricated cells were measured and analyzed. The parameters related to the solar cell performance were determined. Moreover, the impedance spectroscopy of the cell with the best performance was investigated.
Electroluminescence (EL) from single layer thin film devices, comprised of hole transport poly(N-... more Electroluminescence (EL) from single layer thin film devices, comprised of hole transport poly(N-vinylcarbazole) films doped with new emitter molecules, is reported in this article. The structure of each device is ITO/doped PVK/Al. We have studied the IV characteristics as well as the variations of the EL with voltage and current. We have also calculated the HOMO and LUMO energy levels for the new emitter molecules.
Acta Physica Polonica A, 2016
In this paper, dye sensitized solar cells were prepared using titanium dioxide (TiO2) and natural... more In this paper, dye sensitized solar cells were prepared using titanium dioxide (TiO2) and natural dye extracted from purple carrot. The performance of dye sensitized solar cells was significantly improved through the pre-and post-treatments of the fluorinated tin oxide (FTO) glass substrate and the TiO2 film using hydrochloric (HCl), phosphoric (H3PO4), and nitric (HNO3) acids. The results showed that the pre-treatment of the FTO with H3PO4 and the post-treatment of TiO2 with HNO3 resulted in improved efficiencies of 130% and 250%, respectively.
Analytical Letters, 1988
Abstract A new fiber-optic probe for the determination of glucose is developed. Glucose oxidase i... more Abstract A new fiber-optic probe for the determination of glucose is developed. Glucose oxidase is immobilized on a preactivated Immunodyne membrane by direct application of the enzymatic solution to one side of the membrane. The membrane is then placed around the common end of a bifurcated glass fiber optic bundle, and immersed in the sample cell which contains the glucose sample, peroxidase and a colorless dye. Glucose is quantified by the color change when the reaction takes place.
Zeitschrift für Naturforschung B
A solid-state pH sensor was fabricated using a transparent conductive tin oxide film on a glass s... more A solid-state pH sensor was fabricated using a transparent conductive tin oxide film on a glass substrate. The coating of the glass substrate was achieved by a novel simple chemical vapor deposition (CVD) procedure. The response time of the pH sensor was substantially reduced when a thin graphite film was deposited onto the tin oxide conductive film. The sensor slope was found to increase as the temperature of the solution was increased. The performance of the sensor was investigated in the pH range from 0.3 to 11.0. A straight-line calibration graph was achieved throughout the whole range tested, especially when the solution temperature was 80 ℃. The working pH range was found to decrease on the expense of the lower range as the temperature was decreased. Results obtained by the suggested sensor compares very well with conventional pH electrodes where the square of the correlation coefficient was 0.999.
Zeitschrift für Naturforschung B
Several versions of Cu(II) ion selective electrodes (ISE), based on cyclized N,N'-bis(salicyl... more Several versions of Cu(II) ion selective electrodes (ISE), based on cyclized N,N'-bis(salicylidene)-o-phenylenediamine (salophen) complexes with Cu(II), were fabricated for determination of Cu(II) in aqueous solutions. The response of the ISE was optimized by variation of membrane composition and evaluation of various experimental conditions. Near Nernstian slopes (~ 28-32 mV/decade) were obtained for some preparations. The linear range of the ISE ranged from 5 × 10-5 to 1 × 10-2M Cu(II). Coated-wire and coated disc ISE resulted practically in a similar response as screen printed electrodes (SPE). The potentiometric selectivity coefficients (Kij) for all electrodes were determined for Na+, NH4+, Ca2+, Mg2+, Ni2+, Pb2+, Zn2+, Cd2+, Co2+, Fe3+, Hg2+, CO32-, H2PO4-, HPO42-, SO42-, CH3COO-, Br-, I-, NO3-, and SCN-. The selectivity coefficients were in the range from 10-2 to 10-3 for all ions tested except Hg2+, I-, and to less extent Fe3+. Fabricated ISE using the Cu(II)-salophen co...
Bulletin of Environmental Contamination and Toxicology
International Journal of Thin Films Science and Technology
Journal of Nano- and Electronic Physics, 2016
A group of chemical sensitizers of two hydrazonoyl based derivatives were synthesized. These deri... more A group of chemical sensitizers of two hydrazonoyl based derivatives were synthesized. These derivatives contain a good system for efficient light absorption and oxide sensitization. Precursor structure I was reacted with 2,6-diaminopyridine, 2-aminobenzoic acid, 4-aminobenzoic acid, 2-aminopyridine, 2,6-dinitrophenylhydrazine, and diphenylamine. The other precursor, structure (II), was reacted with 2-aminobenzoic acid, 2-amino-3-methyl, and 2-amino-4-methylpyridine. A total of 9 dyes were prepared and evaluated as sensitizers for dye-sensitized solar cells (DSSCs). Full computational calculations using DFT B3LYP 6-31+G were carried out for evaluation of band edge and band gap energies of all compounds. The absorption spectra of these dyes as well as cyclic voltammetry were used for the measurement of the HOMO, LUMO, and energy band gaps. The photovoltaic performance of the fabricated DSSCs was measured in different solutions comprising water, alcohol, phenylhydrazine, and dinitrophenylhydazine.
International Journal of Thin Films Science and Technology, 2016
Journal of Theoretical and Applied Physics, 2016
In this paper, the extract of Trigonella seeds was used as sensitizer for dye-sensitized solar ce... more In this paper, the extract of Trigonella seeds was used as sensitizer for dye-sensitized solar cells (DSSCs). The natural dye was extracted from the seeds using water and alcohol as solvents for the raw material. The UV-Vis absorption spectra of Trigonella extract solution and dye adsorbed on TiO 2 film were measured. DSSCs sensitized by Trigonella extracted using water as a solvent exhibited better performance with efficiency of 0.215 %. The performance of the fabricated DSSCs was attempted to enhance by acid treatment of the FTO substrates with HNO 3 , H 3 PO 4 , and H 2 SO 4 . Electrochemical impedance spectroscopy of the fabricated cells was also carried out.
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Papers by monzir abdel-latif