الفهرس 
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Abstract
ABSTRACT
Name: Salama Mohamed Mohamed
Title of the thesis: Preparation kinetics and characterization of some conducting polymers and their uses in removal of trihalomethanes from drinking water.
Degree: Ph.D of Science in Physical Chemistry, Faculty of Science, Beni- Suef University, Egypt.
The aqueous oxidative chemical polymerization of o-pheylenediamine, o-methylaniline, o-methoxyaniline, o-hydroxyaniline, o-chloroaniline, o-nitroaniline, o- carboxylicaniline and o- sulphonicaniline are investigated in hydrochloric acid solution using potassium dichromate as oxidant at 5 ± 0.2 0C.
All the investigated monomers are polymerized except o-nitroaniline, o-sulphonicaniline and o- carboxylicaniline and this behavior was explained by the molecular orbital calculations.
The effect of hydrochloric acid, potassium dichromate and monomer concentrations on the polymerization of each monomer are studied and the conversion - time curves are plotted and the data are tabulated and graphically represented. from which, the initial reaction rates are calculated and also given in tables.
The orders of polymerization reaction with respect to hydrochloric acid solution, potassium dichromate and monomer concentrations in each polymerization system are determined from the double logarithmic relationship between the initial rates and the concentration of the investigated parameters.
The effect of temperature (5, 10 and 15 0C) on the polymerization rate is investigated for each monomer. The initial and overall rate reactions are calculated, from the relationship between log Ri and 1/T using Arrhenius equation, the activation energy (Ea) for each polymerization system is calculated. The thermodynamic activation parameters (ΔS*) and (ΔH*) are calculated for each polymerization system using Eyring equation. Also, the suggested polymerization mechanism for this type of aqueous oxidative chemical polymerization is proposed.
The polymers obtained at the optimum conditions are characterized by using different characterization tools such as elemental analysis, XPS, IR and UV-visible. The TGA analysis is used to confirm the proposed structures and number of water molecules in each polymeric chain unit. The surface morphology of the obtained polymers is characterized by X-ray diffraction and transmission electron microscopy (TEM).
Some molecular orbital calculations are performed for each monomer and radical cation in order to suggest structure and mechanism. Full geometry optimization was performed at Density Functional Theory (DFT) level of theory. The B3LYP method has been adopted using 6-311G** basis set. The effect of substituent’s of different electron –donating strength on geometry and electronic structure features of o-substituted derivatives was examined. The nucleophalic substitutions were studied using proton detachment energy calculation (PDE) at the level of B3LYP/6-311G**.
The ac conductivity (σac) and dielectric properties were carried out on the polymer samples as a function of frequency and temperature. The ac conductivity was interpreted as a power law of frequency. The frequency exponent (s) was found to less than unity and decreased with the increase of temperature, which suggested that correlated barrier hopping model was the dominant charge transport mechanism.
The obtained polymers were used to reduce trihalomethanes concentration (THMs) from drinking water. The removal efficiency of (THMs) using polymer samples and their composites with multi-walled carbon nano-tubes are calculated using different doses. The method validation, uncertainty, recovery and linearity for (THMs) determination were calculated. The data of adsorption on surface of poly o-substituted aniline derivatives was found to fit well with Langmuir and Freundlish isotherm equations.
_____________________________________________________________Key Words: Kinetics, Aqueous Oxidative, Polymerization, Molecular Orbital Calculations, characterization Conductivity and Trihalomethanes.