الفهرس 
Chapter I: IntroductionOnly 14 pages are availabe for public view
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Abstract
Micelle formation, or micellization, is an important phenomenon not only because a number of important interfacial phenomena, such as detergency and solubilization, depend on the existence of micelles in solution, but because it affects other interfacial phenomena, such as surface or interfacial tension reduction, that do not directly involve micelles. Of late, micelles have become a subject of great interest to the organic chemist and the biochemist, to the former because of their unusual catalysis of organic reactions, to the latter because of their similarity to biological and globular proteins. A clear understanding of the process of micellization is necessary for rational interpretation of the effect of structural and environmental factors on the value of the critical micelle concentration (CMC). So the determination of thermodynamic parameters of micellization and adsorption has played an important role in developing such an understanding about the behavior of surfactants in their media. In this work six biphenyl azo amphiphiles and six biphenyl azomethine amphiphiles were prepared from alkyl-haloacetate and sodium salt of both sulfanilic acid and p-aminobenzoic acid. The biphenyl azo amphiphiles are: (i) p-octyloxy carbonyl methoxy-p’-sodium sulfaonate-biphenyl azobenzene (la). (ii) p-octyloxy carbonyl methoxy-p’-sodium carboxylate-biphenyl azobenzene (Ila). (iii) p-dodecyloxy carbonyl methoxy-p’-sodium sulfaonate-biphenyl azobenzene (IlIa). (iv) p-dodecyloxy carbonyl methoxy-p’-sodium carboxylate-biphenyl azobenzene (IVa). (v) p-cetyloxy carbonyl methoxy-p’ -sodium sulfaonate-biphenyl azobenzene (Va). (vi) p-cetyloxy carbonyl methoxy-p’-sodium carboxylate-biphenyl azobenzene (VIa). The biphenyl azomethine amphiphiles are: (i) p-octyloxy carbonyl methoxy-p’-sodium sulfaonate-biphenyl azomethine (Ib). (ii) p-octyloxy carbonyl methoxy-p’-sodium carboxylate-biphenyl azomethine (lIb). (iii) p-dodecyloxy carbonyl methoxy-p’-sodium sulfaonate-biphenyl azomethine (IIIb). (iv) p-dodecyloxy carbonyl methoxy-p’-sodium carboxylate-biphenyl azomethine (IVb). (v) p-cetyloxy carbonyl methoxy-p’-sodium sulfaonate-biphenyl azomethine (Vb). (vi) p-cetyloxy carbonyl methoxy-p’-sodium carboxylate-biphenyl azomethine(VIb). 1- Elementary analysis, infrared analysis and 1HNMR were used to investigate such surfactants. 2- DSC results proved that, the phase transition between solid and liquid crystalline states has been observed for the synthesized surfactants. 3- The micellization process for the prepared surfactants is controlled by the hydrophobic chain length and temperature. 4- The critical micelle concentration (CMC) decreases with increasing the hydrophobic moiety for both biphenyl azo amphiphiles and biphenyl azomethine amphiphiles. However, temperature increasing causes hydration of the hydrophilic group, which favors micellization. On the contrary, temperature increasing disruption of the structured water surrounding the hydrophobic group, an effect disfavors micellization. 5- Effectiveness (Πcmc) values indicate that, the synthesized biphenyl azomethine amphiphiles are reducing the surface tension more than biphenyl azo amphiphiles. 6- Maximum surface excess (Γmax) and minimum area (Amin) values indicate that, the degree of packing (at aqueous solution / air interface) of biphenyl azoamphiphiles is lower than the corresponding biphenyl azomethine amphiphiles. 7- Studying thermodynamic parameters indicate that, all the synthesized surfactants seem to micellized spontaneously at a given temperature. Micellization process increase with incearsing in the length of the hydrophobic moiety. The heat enthalpy values are all positive due to the endothermic desolvation associated with micellization. The slight increase in the positive entorpy values with increasing the number of methylene group in the hydrophobic part indicating increased randomness of the hydrophobic group of the surfactant to migrate from the solvent environment to the interior of the micelle. 8- The critical range obtained from the equivalent conductance changes with increasing the chain length and the temperature, is not identical to the (CMC) value determined by surface tension method. The former increases with temperature however, the latter decreases. 9- The degree of dissociation (α) increases with dilution. Conversely, it decreases with chain length increasing. The dissociation constants are decreased as the chain length increases. 10- Viscosity, activation energy and activation parameters indicate that, the relation between concentration and viscosity is not a linear relationship, and the increase of viscosity is rather small with concentration in the pre CMC. 11- Activation energy (Ea ) increases with increasing the molecular weight of the prepared surfactants. Also, the activation energy decreases with increasing CMC values. 12- The positive values of (ΔG ) indicate that, the solvation process is spontaneous. But the negative values of (ΔH ) indicate that, the solvation process is exothermic, and the negative values of (ΔS ) indicate that, the degree of freedom is disorded for the solvation process. 13- The variation of both interfacial tension and emulsion stability is independent on the number of carbon atoms in the hydrophobic moiety for the prepared surfactants. The more stable emulsion and more capable surfactants in depressing interfacial tension are IVa,Va, Ib and IIIb compounds. 14- The prepared surfactants have excellent calcium ion stability.