Orientadores: Maria Helena Andrade Santana, Maria Vitoria Lopes Badra Bentley / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica / Made available in DSpace on 2018-08-04T23:17:39Z (GMT). No. of bitstreams: 1 Barbosa_RaqueldeMelo_M.pdf: 4198029 bytes, checksum: b5072f7f5d6c82c75879c1717e1946ed (MD5) Previous issue date: 2005 / Resumo: Resumo: Neste trabalho foi estudada a preparação e caracterização de lipossomas elásticos e elástico-magnéticos projetados para facilitar o transporte transdérmico de moléculas bioativas. Os lipossomas preparados foram do tipo unilamelar, compostos de dimiristoilfosfatidilcolina sintética (DMPC), fosfatidilcolina de soja hidrogenada ou fosfatidilcolina de ovo (PCovo) como componentes estruturais e dos tensoativos derivados do ácido láurico: 'C IND. 12¿¿E IND. 5¿ (polioxietilenoglicol-4-dilauril ester) PEG8L (polioxietilenoglicol-8-luril ester), PEG4DL (polioxietilenoglicol-8-dilauril ester), como componentes elásticos. As propriedades magnéticas foram adicionadas aos lipossomas através da incorporação da magnetita coloidal. A incorporação dos tensoativos nos lipossomos foi feita por dois procedimentos: durante a hidratação do filme lipídico ou por incubação com lipossomas pré-formados. Os lipossomas elásticos foram caracterizados através da quantificação do teor de fosfolipídios, diâmetro médio e distribuição de tamanhos, incorporação dos tensoativos, capacidade de permeação em membranas artificiais com poros de 50 e 30nm, elasticidade e estabilidade física de estocagem. Nos lipossomas elástico-magnéticos foi também caracterizada a incorporação da magnetita coloidal. Os resultados experimentais mostraram que a temperatura de transição de fases do fosfolipídio, a fluidez da bicamada lipídica produzida pela incorporação do tensoativo e a preservação da integridade da partícula foram fatores que determinaram o desempenho dos lipossomas elásticos na permeação através de membranas nanoporosas... Observação: O resumo, na íntegra, poderá ser visualizado no texto completo da tese digital / Abstract: The purpose of this work was to study the preparation and characterization of elastic and elastic-magnetic liposomes designed to facilitate the transdermal transport of drugs. The prepared liposomes were unilamellar, composed by synthetic dymirystoylphosphatidylcholine (DMPC), hydrogenated soy phosphatidylcholine or egg phosphatidylcholine (PCegg) as structural components and by the derivative lauric acid surfactants: 'C IND. 12¿¿E IND. 5¿(polyoxyethylene-5-lauryl ether), PEG4L (polyethyleneglycol-4-lauryl ester), PEG4DL (polyethylenoglycol-4 dilauryl ester), PEG8L (polyethyleneglycol-8-lauryl ester) e PEG8DL polyethyleneglycol-8- dilauryl ester) as elastic components. Magnetic properties were added to elastic liposomes by incorporation of colloidal magnetite. The incorporation of surfactants to liposomes was done by two procedures: during hydration of lipid film or by incubation with preformed liposomes. The elastic liposomes were characterized through their phospholipid contents, mean diameter and size distribution, incorporation of surfactants, capability for permeation through artificial membranes containing 50 or 30 nm porous, elasticity and storage stability. The incorporation of colloidal magnetite was also characterized in elastic-magnetic liposomes. The experimental results show that the phospholipid phase transition temperature, the fluidity of the lipid bilayer generated by surfactant incorporation and the preservation of particle integrity were factors determining the performance of elastic liposomes on permeation through nanoporous membranes. In this context, DMPC and PCegg phospholipids and the surfactants PEG8L and PEG8DL were the best compounds... Note: The complete abstract is available with the full electronic digital thesis or dissertations / Mestrado / Desenvolvimento de Processos Biotecnologicos / Mestre em Engenharia Química

Orientador: Eneida de Paula / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-11T08:33:29Z (GMT). No. of bitstreams: 1 Cunha_ElizabethSousada_M.pdf: 3228323 bytes, checksum: 545a2be4ec32cc1a223c4b4337dc369a (MD5) Previous issue date: 2008 / Resumo: A mitocôndria é uma organela vital, pois em células aeróbicas, ela é responsável pela produção da maior parte da energia química necessária para a célula. A síntese de ATP ocorre por fosforilação oxidativa na Fo,F1-ATPase, usando a energia gerada pela cadeia de transporte de elétr ons, uma série de enzimas presentes na membrana mitocondrial interna. A análise de proteínas de membrana pode ser feita pela técnica de eletroforese, tanto em condições nativas quanto desnaturantes. Neste trabalho analisamos a solubilização de proteínas da membrana interna de mitocôndria de músculo de rato, através do uso de surfatantes zwiteriônicos (ASB-14, ASB-16, CHAPS), não-iônicos (Digitonina, C12E8, Triton X- 100) e aniônico (Colato de sódio) na separação por eletroforese em gel nativo e bidimensional. Desenvolvemos um novo protocolo para preparo de eletroforese em gel nativo, mantendo o tampão de amostra descrito no procedimento de BN-PAGE e adaptando as demais etapas da técnica de acordo com o protocolo de Laemmli et al (1970). Os géis assim preparados em temperatura ambiente mostraram melhor resolução que os pelo método BN-PAGE, foram obtidos menor tempo de corrida (1- 2 horas), sem troca de tampões e com emprego de reagentes de menor custo. Quanto a eficiência dos diferentes surfatantes, usados em uma mesma concentração (43,2 mM), o zwiteriônico ASB-16 foi o melhor solubilizador das proteínas de MMI, tanto em relação a quantidade total de proteína solubilizada como em relação a número de ¿spots¿ visualizados na eletroforese bidimensional, seguido pelo não-iônico Triton X-100. O surfatante não-iônico dodecil maltosídeo foi usado na preparações dos géis 2D em concentrações menores inferiores (20%) do que as indicadas na literatura (10% ou 195,8 mM), sem prejuízo da eficiência de solubilização protéica. Os resultados obtidos com géis nativos mostraram que todos os surfatantes estudados podem ser usados para separar os complexos protéicos da MMI, mas apresentam seletividade específica pelos complexos da Cadeia Respiratória, devendo esse parâmetro ser melhor estudado futuramente, para a determinação de protocolos específicos para isolamento dos diferentes tipos de complexos / Abstract: The majority of the chemical energy produced inside aerobic cells is a result of the oxidative phosphorylation of ATP, inside the mitochondria. A great part of mitochondria proteins are organized into complexes located in the inner mitochondria membrane. Isolation and identification of those proteins have been conducted by electrophoresis, both in native as in denaturant condition. In this work we analysed solubilization of the inner mitochondrial membrane proteins of rat¿s gastrocnemius muscles, through the use of zwitterionic (ASB-14, ASB-16, CHAPS), non-ionic (Digitonin, C12E8, Triton X-100) and anionic (sodium cholate), by native and two-dimensional electrophoresis. We have developed a new protocol for the native gel electrophoresis, using the buffer sample described in BN-PAGE but changing other steps of the technique according to the protocol of Laemmli et al (1970). With this novel protocol, the gels prepared at ambient temperature had a better resolution than the classic BNPAGE technique; with low costs and short-time runs (1-2 hours). As for the effectiveness of surfactants studied to solubilize inner mitochondrial membrane proteins, when used at the same concentration (43.2 mM), the zwitterionic ASB-16 was the best, both accordingly to the total amount of solubilized protein, as for the number of "spots" detected in the two-dimensional electrophoresis, followed by non-ionic Triton X-100. The non-ionic surfactant dodecyl maltoside was used in the 2D electophoresys preparation at lower concentrations (20%) than that recommended in the literature (10% or 195.8 mM) without prejudice in the efficiency of protein solubilization. The results with native gels proved that all the studied surfactants can be used to separate the proteins of MMI, but with different selectivity for each enzymatic complex. This specificity should be better studied in the future, looking for the determination of specific protocols for better isolation of each types of MMI complex / Mestrado / Bioquimica / Mestre em Biologia Funcional e Molecular

M.Cur. (Intensive General Nursing) / The purpose of this study is to identify nursing guide-lines for the nursing of babies that received exogenous surfactant. In view of the fact that the exogenous surfactant therapy is still a very new therapeutic approach for the treatment of hyaline membrane disease there is still a lot to learn about the complications of the treatment. The professional nurse monitors the baby after medication was given, and it is therefore necessary to set out nursing guidelines to guide her in her treatment of the baby. Ten case-studies were done on 10 babies that have already been submitted to the therapy. They were selected from Provincial hospitals in the Johannesburg region. Recurrent events/incidents were identified and used as data from which nursing guide-lines were compiled. A literature study was done to consult other authors' findings on this topic. Recommendations were made at the end of the study concerning applications to practise, education and further research needed.

In industry the effective mixing and de-agglomeration of two solid particles is vital in applications that require the intimate contact of homogeneously mixed reagents. One such application is in the preparation of pyrotechnic delay elements with reproducible burn speeds. The concept of surfactant assisted particle micro-mixing is proposed. This theory is based in the use of two amphiphilic polymeric surfactants to form two separate stable dispersions of the two solid particles to be mixed, but with the subsequent requirement that the dispersants are able to interact with each other. The formation of the individual dispersions allows for the deagglomeration of the particles and thus their preparation for homogeneous mixing, which is facilitated by the interacting surfactants. Low molecular mass block copolymers of styrene and acrylic acid and poly( ethylene oxide)-poly(propylene oxide) (PEO-PPO) surfactants are the proposed dispersants which will allow for the surfactant interaction by means of hydrogen bonding between the poly(acrylic acid) block and the PEO. The poly(styrene-co-acrylic acid) block copolymer will be synthesised via Atom Transfer Radical Polymerisation (ATRP) and subsequently used in the dispersion experiments. The synthesis of the polystyrene macroinitiators to initiate the block copolymerisation of the t-butyl acrylate was carried out satisfactorily, with good molecular masses and molecular mass distributions. In addition, lH-NMR analysis carried out on the polystyrene macroinitiators confirmed their synthesis. The use of the polystyrene macroinitiators was successful in synthesising poly(styrene-co-t-butyl acrylate) block copolymers with slightly higher polydispersities in comparison to the macroinitiatiators themselves, but acceptable. Hydrolysis of the poly(styrene-co-t-butyl acrylate) block copolymer to poly(styrene-co-acrylic acid) was successful in the presence of trifluoroacetic acid as catalyst. Attempts to hydrolyse in basic conditions (NaOH) and alternatively in acidic conditions (HCI) were not successful. Use of the poly(styrene-co-acrylic acid) amphiphilic block copolymer to emulsion polymerise styrene requires the ionised form of the polymer and was therefore not favourable to observe surfactant-surfactant hydrogen bonding. In addition, attempts to synthesise a wax emulsion stabilised by a PEO containing surfactant proved to be unsuccessful. Subsequently, the micro-mixing experiments were carried out by using a poly(acrylic acid) stabilised melamine dispersion and a commercially available PEO containing surfactant stabilised wax emulsion. The interaction between the melamine and the poly(acrylic acid) allows for the formation of a stable melamine dispersion at above 7% poly(acrylic acid) : melamine ratio (mass basis). Analysis by SEM shows that without the poly( acrylic acid) dispersant no wax particles are found to occur on the melamine particle surface. However, in an attempt to determine whether the amount of wax interaction increases with poly(acrylic acid) content, it was found that in the absence of poly(acrylic acid) dispersant, the most amount of wax precipitated out with the melamine. This is possibly attributable to the preferential occlusion of the wax particles between the melamine particles rather than surface attachment. Introduction of the poly(acrylic acid), however, shows via SEM analysis that the hydrogen bond interaction between the acrylic acid group and the ethylene oxide group does occur, since the attachment of the wax particles on the melamine particle surface is observed. Although results show that the surfactant-surfactant interaction allows for the micro¬mixing of particles, some refinement is required with respect to the systems that this phenomenon can be applied to. In addition, factors such as particle type, particle size and surfactant type will influence the micro-mixing interaction. It is therefore recommended that these factors be investigated in order to completely identify the micro-mixing phenomenon. / Dissertation (M Eng (Chemical Engineering))--University of Pretoria, 2006. / Chemical Engineering / unrestricted

The purpose of the work described in this thesis was the synthesis of a new class of surfactants containing chiral cationic end groups and the synthesis of two chiral reactant molecules which would react in the presence of these surfactants. The structures of the surfactant and substrate molecules were designed to maximize their stereochemical interactions and in this way reveal details of the nature of micellar catalysis. In order to indicate why these structures were selected, several examples of micellar catalysis and the factors influencing it will be discussed in the following pages.

The mobility of N-alkyl nicotinamides and their solubilization equilibria in surfactant micellar solution were investigated using an NMR paramagnetic relaxation method. The spin-lattice relaxation times (Tl) . for protons of these compounds were measured in pure D20 and in cationic surfactant solution in the presence and absence of · a low concentration of paramagnetic Ma2+ ions. The rotational motion of these molecules in aqueous phase became slower when the alkyl group changed from methyl to octyl. The increase of the 1H spinlattice relaxation rate (Rl) of the molecules, when surfactants are added, implies the penetration of these solubilizates into micellar phase. The micelle to water phase distribution coefficient, 1-p, was determined by monitoring the change of Rl of the solubilizates upon addition of paramagnetic ions to the aqueous phase. The mole fraction based distribution coefficient, Kx, as well as the free energy of transfer of N-alkyl nicotinamides from the aqueous phase to the micellar phase were calculated. A model was postulated for the interaction of N -alkyl nicotinamide with micelles. Hydrophobic force between the alkyl chains of the solubilizates and the surfactants accounts for the solubilization of N -alkyl nicotinamides and can force the binding of cationic compounds to cationic micelles · despite charge repulsion. With increasing of the alkyl chain length, the hydrophobic force increases, and the interaction between them becomes stronger, and more N -alkyl nicotinamides are solubilizated into the micellar phase.

Complexity in Home and Personal Care appears in several forms – the product, the substrate, and their interactions. The aim of this thesis is to investigate strategies for selecting effective surface-active agents (surfactants) that can be used in combination with other active ingredients in industry-relevant formulations deployed in the personal care sector. This thesis is composed of three parts, each of which involves a study of a complex natural system as it is affected by the addition of a complex chemical mixture. This is done in an effort to expose key features of the design rules for engineering the chemical mixture to enhance baseline performance via synergistic interactions of the formulation components and the natural system components. The first topic is an investigation on how the effectiveness of surface-active agents for removing a mixture of hydrophobic and hydrophilic soils from fabrics is related to the surfactants' physical-chemical features. The second topic is an exploration of compatible surfactant-enzyme systems that can be used in various industrial applications, where the behavior at a variety of interfaces is concomitantly important. Here, the focus is on the effect of surfactant structure and properties on enzyme function (i.e., activity), structural mobility and stability. The third topic is an investigation on the usefulness of micro-Raman spectroscopy for determining in situ chemical information that relates to the effects of a variety of surfactants on the mechanical and textural features of skin.

Effects of aqueous surfactant solutions upon cis/trans isomerization reactions of various N-alkyl-merocyanine dyes (II) were studied. Dramatic rate enhancements were found for all dyes in CTAB and SDS solutions above the CMC. CTAB solutions showed the greatest effect with some dye isomerizations catalyzed in excess of 1000-fold. Increases in either CTAB concentration or dye isomerization rates. N-methyl through N-pentyl dye isomerization rates were measured as a function of CTAB concentration and the data treated according to the pseudophase model for micellar catalysis. KS values ranged from 198 to 2000 M-1 for N-methyl to N-pentyl dyes, respectively. Micellar rate constants also increased as dye hydrophobicity was increased. Thermodynamic activation parameters were determined for N-methyl through N-hexylmerocyanine dyes in CTAB solutions. Rate enhancements in CTAB (above the CMC) relative to those in purely aqueous solutions were shown to be due to a substantial lowering of ΔH‡, for the various dyes. Increased CTAB concentrations of N-methyl dye solutions gave reaction rate increases resulting from a lowering of ΔS‡. In 0.054 M CTAB, increases in reaction rates with increased N-alkyl chain length were due to large increases ΔS‡ (from ca. 0 eu for N-methyl to 13 eu for N-hexyl). The data were discussed in terms of molecular interactions which can occur within the micellar solubilization sites.

No description available.

In order to study the role of electrical charge existing on air bubbles in the kinetics of the particle-bubble adhesion process in froth flotation, the zeta potential of microbubbles in the 40 -to 80-micron size range have been determined by means of a simple microelectrophoresis technique. In general, the bubble charge is determined by the charge of the polar head of the surfactants when ionic surfactants are used to produce bubbles. However, the magnitude of the zeta-potential is reduced when the surfactants are hydrolyzed. When using nonionic surfactants, the bubbles exhibit isoelectric points (i.e.p) in acidic and neutral pH ranges. It appears that the location of an i.e.p. is determined by the acid-base property of the surfactant molecule used. The negative charges observed with air bubbles and oil droplets in the absence of surfactants can be explained by the differences in the hydration energies of H⁺ and OH⁻ ions. An increase in the concentration of ionic surfactants results in an increase in bubble charge. However, the increase is minimal or non-existant when nonionic surfactants are used. The flotation chemistry of the quartz-amine system has been studied using an induction time apparatus constructed in the present work which has a sensitivity limit of 100-150 micro-seconds. The basic unit is similar to the one used by Eigeles and Volova (1960) and Trahar (1983), but it operates with a micro-computer and has a greater sensitivity. It has been found that at a given dodecyl ammonium hydrochloride concentration, the induction time is at a minimum at approximately pH 10.5. At this pH, the collector hydrolizes to form neutral amine and the flotation recovery reaches a maximum, suggesting that iono-molecular species are the surface-active species responsible for flotation. This finding confirms the earlier conclusions obtained using the surface tension (Somasundaran, 1976; Finch and Smith, 1973) and the contact angle (Smith, 1963) techniques. The induction time measurements have also been conducted as a function of particle size, collector concentration, indifferent electrolyte concentration and temperature. The results are compared with flotation data, bubble charge, particle charge and film thickness. Results of the induction time and microflctation experiments conducted using bubbles and particles of known electrical properties indicate that if the potential on the air/water interface is increase to a high value with the same sign as that of the s/l interface (e.g. by adding a suitable surfactant) the flotation kinetic is retarded; conversely, surfactant of the opposite sign can enhance the adhesion process. / M.S.