Orientador: Watson Loh / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Química / Made available in DSpace on 2018-08-16T00:50:27Z (GMT). No. of bitstreams: 1 Silva_AndreLuisCondeda_M.pdf: 1492752 bytes, checksum: 969a849fc8d776ed3dd74fac01294cde (MD5) Previous issue date: 2009 / Resumo: O surfatante cataniônico dodecilsulfato de dodecildimetil-n-hidroxilamônio foi preparado e caracterizado em relação às suas propriedades físico-químicas. O composto apresentou solubilidade muito baixa em água, porém com capacidade de redução da tensão superficial e interfacial entre água e xileno, em ambos os casos com lenta cinética de saturação das interfaces. A solubilidade em solventes orgânicos foi avaliada e constatamos tendência a maior solubilidade em solventes polares como clorofórmio e etanol, e no solvente aromático xileno. O estudo de comportamento termotrópico indicou a existência de fases líquido-cristalinas entre a fase sólida cristalina e a fase líquida isotrópica. A partir dos resultados deste trabalho avaliamos que as possíveis aplicações para estes surfatante estão relacionadas às situações onde a adsorção e deposição seja requerida, e em especial para a preparação de emulsões de água em óleo, com o atributo de baixa solubilidade em ambas as fases, e a possível vantagem de redução de irritabilidade dérmica para cremes e loções. O desenvolvimento desta aplicação requer avanços nos procedimentos de preparação da emulsão de forma a facilitar a adsorção do composto na interface água/óleo / Abstract: The catanionic surfactant dodecyldimehyl-n-hydroxylamonium dodecylsulphate was prepared and its physical-chemical properties were characterized. The surfactant presented very low water solubility, but with ability to reduce the surface tension and the interfacial tension between water and xylene, in both situations with slow kinetics of interface saturation. The solubility in organic solvents was evaluated and the trend for higher solubility in polar solvents like ethanol and chloroform and in the aromatic solvent xylene was noticed. The evaluation of its termotropic behavior was carried out and indicated the existence of liquid crystalline phases between the solid crystalline phase and the isotropic liquid phase. The results of this study indicate the possible applications in situations where adsorption and deposition are required, and for the preparation of water in oil emulsions, with the special feature of low solubility in both phases, with the advantage of reduced skin irritation for creams and lotions. The development of this application requires advancements in the procedures for emulsion preparation in order to allow the surfactant adsorption at the water/oil interface / Mestrado / Físico-Química / Mestre em Química

In this master ‘s thesis, catanionic vesicles formed by the pseudo-double-chain complex CTA – DS were investigated from the point of view of microviscosity. Samplesand of cationic vesicles contained 23, 43 and 53 mol. % of cholesterol and the double-chain surfactant DODAC. Cationic vesicles were prepared for visual observation, their stability was determined by DLS and the prepared system was further investigated. Microviscosity was determined from fluorescence anisotropy. To study the outer part of the membrane, laurdan fluorescent probes were used whereas diphenylhexatriene was used for the inner part of the membrane. This method has been proven to be suitable because it reflects the conditions of the membrane. Moreover, a 1,3-bispyrenylpropane probe forming intramolecular excimers was used to study the microviscosity in the vesicle bilayer. The dicyanovinyljulolidine (DCVJ) probe was applied in the case of the molecular rotor technique. It has been shown that in the case of the DCVJ probe, the molecular rotor technique is practically unusable, due to the fact that the probe has a low quantum yield at low temperatures. Also, the excimer formation of P3P probes does not lead to the expected results. The cationic vesicles do not seem to support this formation, as they are too closely related. This type of probe can be used for the selected system with some restrictions.

This thesis deals with the characterization and preparation of catanionic vesicular systems and their interaction with water-insoluble vitamins. Catanionic vesicles systems was prepared from two differently charged sufractants CTAB and SDS in formation ion pair amphiphile. Stability of vesicles was secured by adding cholesterol with positively charged surfactant DODAC. Were selected vitamin A and vitamin E for solubilization into these vesicles. The next part of this work was focused on determining the efficiency of incorporation these vitamins into the HTMA-DS vesicular system. The characterization of these systems was improved by measurement on a UV-VIS spectrometer, DLS and by HPLC with UV-VIS detector. During measurement by UV-VIS and HPLC the efficiency of solubilization of vitamin A and vitamin E into vesicles was determinated. In both cases higher efficiency was determinated for vesicles with incorporated vitamin A. Higher efficiency for both vitamins was determinated by HPLC. The reason is probably the higher sensitivity of the metod, work in labs with dark glass and preparing individuals samples into vials, which were inserted into the device for individual dosing by injector. The work serves primary evaluation results in view of the vesicular system for use in pharmaceutical application like carrier non-polar vitamins.