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Effects of high-temperature annealing on electron spin resonance in SiOx films
prepared by R. F. sputtering system

Research Abstract

Electron spin resonance (ESR) spectra are investigated in order to analyze paramagnetic defects in amorphous
SiOx films with 0.8≤x≤1.87 prepared by a co-sputtering of Si-wafer chips and a SiO2 disk target. Effects of the
thermal annealing at 900 °C and 1100 °C on the ESR spectra are also investigated. Four types of silicon
dangling bond centers with forms of •Si≡Si3−nOn (n=0, 1, 2 or 3) are assumed in order to simulate the ESR
spectra. The random bonding model appears to describe the network structure of the films with x~2, that is,
near the stochiometric composition of SiO2. It is suggested that the structural fluctuation around silicon
dangling bonds is larger in the sputtered SiOx films used in the present work in comparison with those
prepared by plasma-enhanced chemical vapor deposition.

Research Authors
A.M.A. Shamekh ,N. Tokuda a, T. Inokuma
Research Department
Research Journal
Journal of Non-Crystalline Solids
Research Pages
PP. 981–985
Research Rank
1
Research Vol
Vol. 357
Research Year
2011

Annealing Effects on Cathodoluminescence Properties of SiOx Films
Deposited by Radio Frequency Sputtering

Research Abstract

The effects of high-temperature thermal annealing on cathodoluminescence (CL) spectra in SiOx (0:9  x  1:87) films prepared by radiofrequency
sputtering are investigated. The CL intensities for the as-deposited films are weak but they increase after thermal annealing at 900 and
1100 C. One of features in the CL spectra for the films annealed at 1100 C is a peak at a photon energy of 2:7 eV with an asymmetric tail on the
lower energy side. In order to analyze the spectral features, optical transition energies are calculated for Sin clusters with n ¼ 2{5, embedded in a
SiOx matrix, by ab initio molecular orbital calculation. In addition, the probabilities of formation are statistically estimated for those Si clusters
under the assumption of a chemically ordered random network for the SiOx network. The comparison of the experimental results with the
calculated transition energies and the statistics of the Si clusters suggests that a contribution of the Si2 clusters to the CL spectra are dominant,
whereas those of the Sin clusters with n > 3 are considerably small. # 2011 The Japan Society of Applied Physics

Research Authors
Ahmed Mohamed Ahmed Abd El-Razek Shamekh1, Norio Tokuda, and Takao Inokuma
Research Department
Research Journal
Japanese Journal of Applied Physics, 01BF04
Research Rank
1
Research Vol
Vol. 50
Research Year
2011

New polymer syntheses, part 45: Corrosion inhibition behavior
of novel polyurea derivatives based on diarylidenecycloalkanone
moieties in the polymers backbone

Research Abstract

A novel class of interesting polyurea derivatives
6a-c and 7a-c was synthesized using solution polycondensation
technique by the interaction of 1 mole of bis (2-
aminothiazol-4-ylbenzylidene)cycloalkanones monomers
3a,b with one moles of diisocyanate compounds in pyridine.
The model compounds 4 and 5 were synthesized by the
interaction of one mole of monomers 3a or 3b with two
moles of phenylisocyanate in pyridine and their structures
were confirmed by correct elemental and spectral analyses.
The resulting polymers were characterized by elemental
and spectral analyses, beside solubility and viscometry
measurements. X-ray analysis showed these polymers
having high degree of crystallinity in the region 2θ=5–
60°. In addition, the morphological properties of selected
examples were tested by SEM, and the electrical properties
of these polymers were measured. Moreover the corrosion
inhibition behavior of diarylidenecycloalkanone monomers
and selected examples of polyurea derivatives were carried
out on steel in 0.5 M H2SO4 at 40°C giving cathodic,
anodic and mixed inhibition.

Research Authors
Kamal I. Aly & Mahmoud A. Hussein
Research Department
Research Journal
Journal Polymer Research
Research Member
Research Pages
PP.607-620
Research Rank
1
Research Vol
Vol. 17
Research Year
2010

New polymer syntheses, part 45: Corrosion inhibition behavior
of novel polyurea derivatives based on diarylidenecycloalkanone
moieties in the polymers backbone

Research Abstract

A novel class of interesting polyurea derivatives
6a-c and 7a-c was synthesized using solution polycondensation
technique by the interaction of 1 mole of bis (2-
aminothiazol-4-ylbenzylidene)cycloalkanones monomers
3a,b with one moles of diisocyanate compounds in pyridine.
The model compounds 4 and 5 were synthesized by the
interaction of one mole of monomers 3a or 3b with two
moles of phenylisocyanate in pyridine and their structures
were confirmed by correct elemental and spectral analyses.
The resulting polymers were characterized by elemental
and spectral analyses, beside solubility and viscometry
measurements. X-ray analysis showed these polymers
having high degree of crystallinity in the region 2θ=5–
60°. In addition, the morphological properties of selected
examples were tested by SEM, and the electrical properties
of these polymers were measured. Moreover the corrosion
inhibition behavior of diarylidenecycloalkanone monomers
and selected examples of polyurea derivatives were carried
out on steel in 0.5 M H2SO4 at 40°C giving cathodic,
anodic and mixed inhibition.

Research Authors
Kamal I. Aly & Mahmoud A. Hussein
Research Department
Research Journal
Journal Polymer Research
Research Member
Research Pages
PP.607-620
Research Rank
1
Research Vol
Vol. 17
Research Year
2010

New Polymer Syntheses Part 53. Novel Polyamides of
Diarylidenecycloalkanone Containing Azo Groups in the Polymer
Backbone: Synthesis and Characterization

Research Abstract

A new interesting class of polyamides of diarylidenecycloalkanone containing azo
groups in the polymer backbone 6a-d was synthesized by a solution polycondensation
reaction of bis 2-aminoarylidene monomers 3a,b with 4,40-azodibenzoyl dichlorides and
3,30-azodibenzoyl dichlorides in NMP as a solvent, using anhydrous LiCl as a catalyst
at room temperature. The model compounds 4, 5 were synthesized by the interaction of
one mole of bis 2-aminoarylidene monomers 3a,b with two moles of benzoyl chloride
using anhydrous LiCl as a catalyst in NMP at room temperature. The resulting polymers
were characterized by elemental and spectral analyses, besides solubility and
viscometry measurements. The thermal properties of those polymers were evaluated
by TGA, DTG and DTA measurements and correlated to their structural units.
X–ray analysis of the polymers showed that polyamides based on para-azo linkage have
a higher degree of crystallinity than those based on meta-azo linkage in the region
2h¼560. In addition, the morphological properties of selected examples were tested
by SEM.

Research Authors
K. I. Alya; M. A. Abdel-Rahman; M. A. Hussein
Research Department
Research Journal
International Journal of Polymeric Materials
Research Member
Research Pages
PP. 553-569
Research Rank
1
Research Vol
Vol. 29
Research Year
2010

New Polymer Syntheses Part 53. Novel Polyamides of
Diarylidenecycloalkanone Containing Azo Groups in the Polymer
Backbone: Synthesis and Characterization

Research Abstract

A new interesting class of polyamides of diarylidenecycloalkanone containing azo
groups in the polymer backbone 6a-d was synthesized by a solution polycondensation
reaction of bis 2-aminoarylidene monomers 3a,b with 4,40-azodibenzoyl dichlorides and
3,30-azodibenzoyl dichlorides in NMP as a solvent, using anhydrous LiCl as a catalyst
at room temperature. The model compounds 4, 5 were synthesized by the interaction of
one mole of bis 2-aminoarylidene monomers 3a,b with two moles of benzoyl chloride
using anhydrous LiCl as a catalyst in NMP at room temperature. The resulting polymers
were characterized by elemental and spectral analyses, besides solubility and
viscometry measurements. The thermal properties of those polymers were evaluated
by TGA, DTG and DTA measurements and correlated to their structural units.
X–ray analysis of the polymers showed that polyamides based on para-azo linkage have
a higher degree of crystallinity than those based on meta-azo linkage in the region
2h¼560. In addition, the morphological properties of selected examples were tested
by SEM.

Research Authors
K. I. Alya; M. A. Abdel-Rahman; M. A. Hussein
Research Department
Research Journal
International Journal of Polymeric Materials
Research Member
Research Pages
PP. 553-569
Research Rank
1
Research Vol
Vol. 29
Research Year
2010

New Polymer Syntheses Part 53. Novel Polyamides of
Diarylidenecycloalkanone Containing Azo Groups in the Polymer
Backbone: Synthesis and Characterization

Research Abstract

A new interesting class of polyamides of diarylidenecycloalkanone containing azo
groups in the polymer backbone 6a-d was synthesized by a solution polycondensation
reaction of bis 2-aminoarylidene monomers 3a,b with 4,40-azodibenzoyl dichlorides and
3,30-azodibenzoyl dichlorides in NMP as a solvent, using anhydrous LiCl as a catalyst
at room temperature. The model compounds 4, 5 were synthesized by the interaction of
one mole of bis 2-aminoarylidene monomers 3a,b with two moles of benzoyl chloride
using anhydrous LiCl as a catalyst in NMP at room temperature. The resulting polymers
were characterized by elemental and spectral analyses, besides solubility and
viscometry measurements. The thermal properties of those polymers were evaluated
by TGA, DTG and DTA measurements and correlated to their structural units.
X–ray analysis of the polymers showed that polyamides based on para-azo linkage have
a higher degree of crystallinity than those based on meta-azo linkage in the region
2h¼560. In addition, the morphological properties of selected examples were tested
by SEM.

Research Authors
K. I. Alya; M. A. Abdel-Rahman; M. A. Hussein
Research Department
Research Journal
International Journal of Polymeric Materials
Research Member
Research Pages
PP. 553-569
Research Rank
1
Research Vol
Vol. 29
Research Year
2010

Square-Wave Cathodic Adsorptive Stripping Voltammetric Determination of 3-Hydroxyflavone, Morin and Hesperidin in Bulk Form and Biological Fluids in Absence and Presence of Cu(II)

Research Abstract

As flavonoids show pharmacological activity, in the present investigation, an economical
and efficient method for their trace determination was developed. In this context, the interfacial
behavior of three flavonoids, 3-hydroxyflavone (3HF), morin and hesperidin (Hesp) was studied
on the hanging mercury dropping electrode (HMDE) by phase sensitive ac voltammetry and cyclic
voltammetry (CV). The investigated flavonoids were strongly adsorbed which is the prerequisite
step for applying the cathodic adsorption stripping voltammetric determination of some flavonoids.
Based on the adsorption character of investigated flavonoids onto the surface of the HMDE,
validated, simple, fast and sensitive square-wave cathodic adsorptive stripping voltammetric
(SWCASV) procedure for the quantification of the flavonoids under investigation in bulk form
and in biological fluids was described. Moreover, controlled adsorptive accumulation of the Cu(II)
complex of flavonoids was also achieved to assay indirect determination of 3HF, morin and Hesp
via the reduction of the formed complex. Operational and solution conditions for the quantitative
ultra-trace determination of the investigated flavonoids were optimized in the absence and presence
of Cu(II). Limits of detection of 4.4 × 10-9, 7.19 × 10-9 and 7.54 × 10-9 mol L-1 3HF, morin and
Hesp in bulk form were achieved using SWCASV, respectively.

Research Authors
Yassien M. Temerk,* Mohamed S. Ibrahim and Mohammed Kotb
Research Department
Research Journal
Journal of Brazillian Chemical Society
Research Rank
1
Research Vol
Vol. 22, No. 11
Research Year
2011
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