Study of Geometrical Optimization and Some Electronic Properties of D-B-A Molecular System

This work deals with designing donor - bridge - acceptor molecular system depending on Aviram – Ratner model and calculating the geometrical parameters and energies for the D- B-A and it is components. Benzene ring is the basic part for all the components of such molecular system. The LUMO-HOMO energy gap for the studied structures showed that the D-B-A molecular system has a suitable small energy gap. The results showed that this new molecular system is more reactive in charge transfer process and has good semiconductor properties. Keywords:B3LYP , DFT, , energy gap, HOMO ,LUMO and polarizability

Theoretical Study of Electronic Properties of Pyridine, Pyrimidine, Pyrazine and Pyridazine via Density Functional Theory

Theoretical studies on pyridine, pyrimidine, pyrazine and pyridazine molecules were performed using DFT. Based on B3LYP with 6-31(d, p)basis sets was used to investigate the effect of different position of nitrogen atom on the electronic and structure properties of benzene. The optimized structure, total energies, electronic states, energy gaps, ionization potentials, electron affinities, chemical potential, global hardness, softness, global electrophilicity, dipole moment and dipole polarizability were calculated. The harmonic vibration frequencies calculated and compared with available experimental data. The results showed a decrease in gap energies and improve the electronic properties. Keywords: B3LYP, DFT, optimization, energy gap, and vibration frequency

Preparation and Study of Optical Properties of (Polymer-Nickel Nitrate) Composite

Polymer composite of polyvinyl alcohol (PVA), nickel nitrate  have been prepared by solution cast method for different doping concentrations of nickel nitrate. The optical characterization has been done by analyzing the absorption spectra in the spectral region 200–800 nm. It was found that the optical energy gap decreases with increasing NiNO3 content.  The refractive index (n), extinction coefficient (k), static dielectric constant have been calculated for the investigated films. The optical constants are changing with increase the weight percentages of nickel nitrate. Key words: composite, polymer,  optical constants, nickel nitrate 

Investigation of Chloro Pentaammine Cobalt(III) Chloride- Polyvinyl Alcohol Composites

Conductive polymer composites have been widely used in industrial applications, such as  biomedical devices , self-heating materials, electrostatic dissipation and over current protectors. This paper investigate the study of the effects of Chloro  Pentaammine Cobalt(III) Chloride complexes on  Electrical  properties of polyvinyl alcohol. samples were prepared using casting technique. The experimental Results show that the electrical conductivity  of polyvinyl alcohol is increased with increasing the weight percentages of  Chloro  Pentaammine Cobalt(III) Chloride complexes and temperature. The activation energy of D.C electrical conductivity is decreased  with increase of Chloro  Pentaammine Cobalt(III) Chloride complexes concentration. keywords: polyvinyl alcohol,  conductivity, activation energy , Composites

Preparation and Characterization of (PMMA-Berry Paper or Plan Leaves) Composites

In this paper, study the effect of addition the Berry Paper or Plan Leaves on optical properties of PMMA. The samples have been prepared by casting technique and different thickness. . The absorption and transmission spectra have been recorded in the wavelength range (200 – 800) nm. The experimental results show that the absorption coefficient, energy gap of the indirect allowed and forbidden  transition, extinction coefficient, read and imaginary dielectric constant and refractive index are changing with increase the of Berry Paper or Plan Leaves concentration

Studying the Effect of KCl Addition on the Electrical Properties of Polystyrene

In this work, samples of pure polystyrene and polystyrene (PS) doped with (KCl) were prepared using casting method .The effect of addition of different concentrations of potassium chloride on electrical properties of polystyrene have been studied, also the effect of temperature on (PS-KCl) composite , then the variation of activation energy of D.C electrical conductivity with KCl concentrations was studied. The results show that the electrical conductivity was increased with increasing the KCl concentration and temperature and the activation energy was decreased with increasing KCl concentration. Key words: polymer, PS, potassium chloride, electrical properties, conductivity

Preparation of (PS-PMMA) Copolymer and Study The Effect of Sodium Fluoride on Its Optical Properties

Composites materials are used in many applications: solar cells, elements, light emitting diodes (LED), optoelectronic device, industrial applications in aircraft, military and car industry for their low cost, light weight, electrical properties, mechanical and optical properties. In this work, preparation of PS-PMMA copolymer have been investigated.  The sodium fluoride was add to PS-PMMA copolymer with concentrations are (0,1,2,3) wt.%. The samples were prepared casting technique. The optical properties of composites in the wavelength range (200-800) nm. The results showed that the absorption coefficient, extinction coefficient, refractive index and  real and imaginary dielectric constants PS-PMMA copolymer are increasing with increase the sodium fluoride concentration. Keyword: composite, copolymer, absorbance, dielectric constants

Preparation of (Pomegranate Peel- Polystyrene) Composites and Study their Optical Properties

In this work, samples of pure polystyrene and polystyrene (PS) doped with (pomegranate peel)  were prepared using casting method .The effect of addition of pomegranate peel (PP) concentration on optical properties of poly styrene have been studied in the wavelength range (200-800)nm. The absorption coefficient, energy gap, refractive index and extinction coefficient have been determined. The results show that the optical constants change with increase of PP concentration. Key words: polymer , Polystyrene, pomegranate peel, Optical properties, absorbance

Optical Properties of (PVA-CoCl2) Composites

Polymers are used in a wide range of manufacture applications for their low cost, light weight, mechanical and optical properties. In this paper, study effect of addition cobalt chloride on  optical  properties of poly-vinyl alcohol(PVA). The cobalt chloride was add to poly-vinyl alcohol with weight percentages are (0,1,2,4) wt.%. The absorption and transmission  spectra has been recorded in the wavelength range (200-800) nm. The experimental results showed that the absorption coefficient, optical energy gap, extinction coefficient, refractive index and  real and imaginary dielectric constant effected by addition different weight percentages from cobalt chloride. Keyword: polymer, optical constants, absorption, cobalt chloride

Preparation of [Co(NH3)5Cl]Cl2 Complexes and Characterization of (PVA- [Co(NH3)5Cl]Cl2]) Composites

In this paper , preparation of  [Co(NH3)5Cl]Cl2 complexes and study the effect of addition [Co(NH3)5Cl]Cl2 complexes on optical properties of polyvinyl alcohol. The  samples have been prepared by casting technique and different thickness. . The absorption and transmission spectra has been recorded in the wavelength range ( 200 – 800 ) nm. The experimental results show that the absorption coefficient, energy gap of the indirect allowed and forbidden  transition, extinction coefficient, read and imaginary dielectric constant and refractive index are changing with increase the of [Co(NH3)5Cl]Cl2 concentration. Key words: polymer, optical properties, complexes