Orientador: Sandra Cristina dos Santos Rocha / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica / Made available in DSpace on 2018-08-04T01:48:08Z (GMT). No. of bitstreams: 1 Donida_MartaWilk_D.pdf: 11312080 bytes, checksum: bb1dd03e1f1adcf362e6bfcdcf1ba9c5 (MD5) Previous issue date: 2004 / Resumo: O recobrimento de partículas em leito de jorro tem aplicações em diversos produtos como comprimidos, cosméticos, alimentos, sementes, fertilizantes, etc. No processo de recobrimento o desempenho é dependente de um conjunto de características do sólido a ser recoberto, da suspensão de revestimento, da adesão líquido-sólido e das condições operacionais. O objetivo deste trabalho é analisar o desempenho do processo de recobrimento em leito de jorro verificando as influências das características do sólido (tamanho, forma, densidade, porosidade, e ângulo de contato) e da suspensão (densidade, reologia, tensão superficial e molhabilidade). Para este estudo foram utilizados diferentes tipos de partículas (esferas de vidro, placebos, poliestireno, etc.) e diferentes formulações de suspensões poliméricas aquosas que ofereçam a variação das características, do sólido e da suspensão, que influenciam o processo. O recobrimento foi realizado em leito de jorro, em condições operacionais pré-fixadas, para cada conjunto partícula-suspensão, mantendo estabilidade fluidodinâmica do leito para as diferentes partículas. Para quantificar a influência das características do sólido e da suspensão no processo de recobrimento foram avaliadas a taxa de crescimento, a eficiência e a qualidade do recobrimento (superfície, distribuição do filme, porosidade). O estudo das influências das características do sólido e do líquido no processo de recobrimento foi realizado em duas etapas: primeira etapa:o recobrimento de partículas de propriedades físicas distintas com uma única suspensão de recobrimento; segunda etapa: recobrimento de um único tipo de partícula com suspensões de recobrimento de diferentes características físico-químicas. Identificou-se que o ângulo de contato entre a suspensão de recobrimento e a superfície das partículas pode ser utilizado como indicativo do tipo de operação unitária a ser obtida no leito de jorro: secagem da suspensão ou recobrimento das partículas. A adesão da suspensão na superfície da partícula, durante o processo de recobrimento e secagem de suspensão em leito de jorro, não é dependente apenas do trabalho de adesão, ou seja, das forças interfaciais, mas de um conjunto de variáveis como o comportamento fluidodinâmico, o atrito inter-partícula, a atomização da suspensão e mudança da molhabilidade das interfaces durante o processo. A interação inicial da partícula inerte-suspensão determina a operação (recobrimento ou secagem), enquanto a interface filme-suspensão, ou seja, forças de adesão entre a superfície recoberta e a suspensão, pode ser responsável pelo processo de recobrimento em relação à eficiência e crescimento por formação de camadas de filme. A eficiência do processo mostrou ser influenciada por uma interferência complexa de mais de uma característica, ou seja, o resultado de um conjunto de condições interfaciais, reológicas, operacionais e de atomização da suspensão. Pôde-se verificar que as propriedades fisico-químicas influenciam significativamente o crescimento das partículas. As partículas crescem mais quando a suspensão de recobrimento possui maior concentração de sólidos, maior densidade, maior viscosidade aparente e maior força de adesão com a superfície da partícula. As mudanças da molhabilidade das interfaces sólido-líquido durante o processo de recobrimento afetam a eficiência do processo / Abstract: Coating of partic1es in spouted bed can be applied to several products such as tablets, cosmetics, foodstuff, seeds, fertilizers, etc. In the coating process, the performance depends upon the characteristics of the solids to be coated, the coating suspension, the liquid-solid adhesion and the operational conditions. The objective of this work is to analyze the performance of the coating process into a spouted bed verifying the influences of the solid characteristics (size, shape, density, porosity and contact angle) and the suspension characteristics (density, rheology, surface tension, and wettability). To accomplish that, different types of partic1es were used (glass beads, placebo' s tablets, polystyrene, etc) and different aqueous polymeric suspension formulations to obtain the variation in the characteristics to be studied, and influence the process. The study of the influences of the solid and the liquid characteristics in the coating process were carried out in two steps. First step: coating of the partic1es with different physical properties using a single suspension formulation; second step: coating of a single type of partic1e using coating suspensions with different physicochemical properties. It was identified that the contact angle between the coating suspension and the partic1es surface can be used as an indicator of the type of unit operation obtained in the spouted bed: suspension drying or partic1e coating. Suspension adhesion on the partic1e surface, during the coating and the drying into a spouted bed, is not dependent only on the adhesion work (interfacial forces), but also on a series of variables like the fluid dynamic behavior of the bed, inter-partic1es friction, suspension atomization and the change on the wettability of the surfaces during the process. The initial interaction of the inert particle-suspension determines the operation, either drying or coating, while the interface film-suspension (attraction between the coated surface and the suspension) can be responsible for the coating process in relation to its efficiency and the growth of film layers on the particles. The process efficiency seems to be influenced by a set of interfacial, rheological, operational and atomization conditions. It can be verified that the physicochemical properties influence significant1y the growing of the partic1es. Partic1es grow more when the suspensions have higher solids concentrations, greater density, greater apparent viscosity and greater adhesion attraction with the particle surface. The changes in the wettability of the solid-liquid interface during the coating process affect the process efficiency / Doutorado / Engenharia de Processos / Doutor em Engenharia Química

Orientador: Mário Noboru Tamashiro / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Física Gleb Wataghin / Made available in DSpace on 2018-08-26T19:25:53Z (GMT). No. of bitstreams: 1 Braga_FilipeLeoncio_D.pdf: 3256250 bytes, checksum: 73d43bfd44605cb6f23213feb8aeedf9 (MD5) Previous issue date: 2015 / Resumo: Modelos termo-estatísticos que tentam reproduzir o comportamento de soluções aquosas de polímeros foram amplamente estudados ao longo dos anos. Entretanto, o número de trabalhos relacionados a sistemas aquosos contendo polímeros e sais adicionados ainda é bem restrito. Na tese desenvolvida, abordamos através de uma modelagem de Flory-Huggins a formação de sistemas aquosos bifásicos contendo cadeias poliméricas longas de polietileno-glicol em misturas contendo sais inorgânicos monovalentes. Dentro da modelagem, a competição entre a formação de ligações de hidrogênio por parte das moléculas de água e os monômeros da cadeia polimérica, além das interações íon-dipolo entre água e os íons dos sais dissociados, desempenham papel fundamental na formação das configurações de equilíbrio. Através de ajustes numéricos de dados experimentais, para cada tipo de sal introduzido na mistura, com previsões do modelo para as menores temperaturas para a formação das duas fases, as chamadas Cloud Point Temperatures (CPT), encontramos um conjunto de quatro parâmetros de interação que possibilitam a reprodução adequada do comportamento contínuo das CPT's em função das concentrações dos solutos / Abstract: Thermal-statistical models that try to reproduce the behavior of aqueous polymer solutions have been extensively studied over the years. However, the number of articles related to aqueous systems containing polymers and added salts is still very restricted. Across the developed thesis, we work with a Flory-Huggins theory to model the formation of aqueous two-phase systems containing long-polymer chains of polyethylene-glycol in mixtures containing monovalent inorganic salts. Within the model, the competition between the hydrogen-bond formation between water molecules and the monomers of the polymer chain, in addition to the ion-dipole interactions between water and the dissociated salt ions play a key role in shaping equilibrium configurations. Through numerical fits of experimental data for each type of salt introduced into the mixture with model predictions for the lowest temperatures for the formation of two phases, so-called Cloud Point Temperature (CPT), we find a set of four parameters of interaction that enable proper representation of the continuous behavior of CPT's as a function of the solutes concentration / Doutorado / Física / Doutor em Ciências

С помощью объемного варианта сорбционного метода изучена сорбция воды пленками ПАА, ПАК, ПМАК и смесями ПАА-ПАК, ПАА-ПМАК разного состава. Измерены теплоты смешения образцов с водой с использованием микрокалориметра типа Тиана-Кальве. Рассчитаны разности химических потенциалов воды ∆µ1, полимеров и смесей ∆µ2, энергии Гиббса смешения полимеров с водой ∆gm. Определены энергии Гиббса, энтальпии и энтропии смешения компонентов в полимерных композициях. Показано, что сорбционная способность систем ПАА-ПАК, ПАА-ПМАК определяется их структурой и сродством к воде. ПАК ведет себя как плотноупакованный полимер, имеющий высокое сродство к воде, а сорбция воды ПМАК свидетельствует о менее плотной упаковке цепей и меньшему сродству к воде. Сорбция воды смесями немонотонно изменяется с составом композиции. Установлено, что смешение всех систем с водой сопровождается уменьшением энергий Гиббса (Δgm < 0), величина ∂2g/∂ω22 > 0, что указывает на образование термодинамически устойчивых систем. Чем б льше сорбционная способность полимера или смеси, тем более отрицательны величины Δgm. Обнаружено, что растворение в воде всех изученных систем сопровождается экзотермическим тепловым эффектом. Отклонения энтальпий смесей от аддитивности положительны для всех систем кроме смеси ПАА-ПМАК с ωПАА < 0,2, что свидетельствует о хорошем взаимодействии полимеров друг с другом. Установлено, что энергии Гиббса смешения ПАА с ПАК и ПМАК полученные двумя методами: с помощью расчета по энергиям Гиббса растворения систем и с помощью уравнения Флори-Хаггинса, хорошо коррелируют друг с другом. Показано, что что смешение ПАА с ПАК сопровождается экзотермическим тепловым эффектом во всей области составов и уменьшением энергии Гиббса вплоть до содержания 90% ПАА. При этом ∆gx и ∆hx близки по величине, и энтропийный вклад в совместимость компонентов T∆sx очень невелик. Таким образом, термодинамическая совместимость ПАА с ПАК обусловлена, главным образом, энергетическим взаимодействием компонентов. Обнаружено, что смеси ПАА-ПМАК образуются с отрицательной энергией Гиббса смешения (∆gx<0) и знакопеременной энтальпией смешения: при содержании ПАА менее 20% ∆hx > 0,а при содержании более 20% – ∆hx<0. Энтропия смешения положительна во всей области составов. / Using the volumetric version of the sorption method, water sorption was studied with PAM, PAA, PMAA films and PAM-PAA, PAM-PMAA mixtures of various compositions. The heats of mixing samples with water were measured using a Tiana-Calve type microcalorimeter. The differences between the chemical potentials of water ∆µ1, polymers and mixtures ∆µ2, Gibbs energy of mixing polymers with water ∆gm are calculated. The Gibbs energies, enthalpy, and entropy of mixing of the components in polymer compositions are determined. It was shown that the sorption ability of PAM-PAA, PAM-PMAK systems is determined by their structure and affinity for water. PAA behaves as a close-packed polymer with a high affinity for water, and the sorption of PMAA water indicates a less dense packing of chains and a lower affinity for water. Sorption of water mixtures non-monotonously changes with the composition. It was found that the mixing of all systems with water is accompanied by a decrease in Gibbs energies (Δgm <0), the value ∂2g/∂ω22> 0, which indicates the formation of thermodynamically stable systems. The greater the sorption capacity of the polymer or mixture, the more negative the Δgm values. It was found that dissolution of all the studied systems in water is accompanied by an exothermic thermal effect. Deviations of the enthalpies of the mixtures from additivity are positive for all systems except the PAM-PMAA mixture with ωPAM <0.2, which indicates a good interaction of the polymers with each other. It was established that the Gibbs energies of mixing PAM with PAA and PMAA were obtained by two methods: using the Gibbs energies of dissolution of systems and using the Flory-Huggins equation, they correlate well with each other. It was shown that the mixing of PAM with PAA is accompanied by an exothermic thermal effect in the entire composition range and a decrease in Gibbs energy up to the content of 90% PAM. Moreover, ∆gx and ∆hx are close in magnitude, and the entropy contribution to the compatibility of the components of T∆sx is very small. Thus, the thermodynamic compatibility of PAM with PAA is mainly due to the energy interaction of the components. It was found that PAM-PMAA mixtures are formed with a negative Gibbs mixing energy (∆gx <0) and an alternating mixing enthalpy: with a PAM content of less than 20%, ∆hx> 0, and with a content of more than 20%, ∆hx <0. The entropy of mixing is positive throughout the composition field.

O presente estudo teve como objetivo obter e caracterizar complexos binários e ternários de benznidazol (BNZ) com ciclodextrinas e polímeros hidrossolúveis com a finalidade de melhorar a solubilidade do fármaco. Efetuou-se a caracterização físico-química do fármaco avaliando-se solubilidade, calorimetria exploratória diferencial (DSC), termogravimetria (TGA), investigação de novas formas cristalinas e a definição de parâmetros para o ensaio de dissolução intrínseca. Posteriormente, esses dados foram utilizados como referência nos estudos de caracterização dos complexos de inclusão. Os complexos binários utilizaram as ciclodextrinas naturais &#945;CD, &#946;CD e &#947;CD, e os ternários a &#946;CD e HP&#946;CD e adição de 1,0% de polímeros hidrossolúveis (povidona e copovidona). Os complexos foram secos em estufa e adicionalmente dois métodos de preparo co-evaporação e liofilização foram empregados para comparação e escolha do mais adequado. O estudo de caracterização dos complexos foi realizado através do método de solubilidade de fases, DSC e TGA. A constante de estabilidade, a eficiência de complexação e solubilidade sugeriram maior interação do fármaco com a &#946;CD. Nos complexos ternários, a utilização de copovidona foi mais efetiva que a povidona. Houve aumento da solubilidade quando os complexos foram preparados pelo método de liofilização. A melhor solubilidade foi alcançada pelos complexos BNZ:&#946;CD (0,84 mg/mL) e BNZ:&#946;CD:copovidona (0,86 mg/mL) preparados pelo método de liofilização. / The present study was aimed to obtain and characterize binary and ternary complexes of benznidazole (BNZ) with cyclodextrins and water-soluble polymers with the purpose to improve the solubility of drug. It was performed the physicochemical characterization of BNZ by differential scanning calorimetry (DSC), thermogravimetry (TGA), investigation of new crystalline forms and the definition of parameters for the intrinsic drug dissolution test of intrinsic dissolution. Subsequently, these informations were used as reference in the studies of characterization of the inclusion complexes. The binary complexes were prepared with the cyclodextrins &#945;CD, &#946;CD and &#947;CD and the ternary with &#946;DC and HP&#946;CD and addition of 1.0% of water-soluble polymers (povidone and copovidone). The complexes were dried in tray drayer and additionally two methods of preparation coevaporation and lyophilization were employeed for comparison and the best was selected. The characterization of the complexes was carried out by phase-solubility method, DSC and TGA. The constant of stability, the efficiency of complexation and solubity suggested higher interaction of the drug with the &#946;CD. In the ternary complexes, the use of copovidone was more effective in the solubility than to povidone. There was an increased of solubility when the complexes were prepared by lyophilization. To best solubility was achieved by the complexes BNZ:&#946;CD (0.84 mg/ml) and BNZ:&#946;CD:copovidone (0.86 mg/ml) prepared by lyophilization method.

O presente estudo teve como objetivo obter e caracterizar complexos binários e ternários de benznidazol (BNZ) com ciclodextrinas e polímeros hidrossolúveis com a finalidade de melhorar a solubilidade do fármaco. Efetuou-se a caracterização físico-química do fármaco avaliando-se solubilidade, calorimetria exploratória diferencial (DSC), termogravimetria (TGA), investigação de novas formas cristalinas e a definição de parâmetros para o ensaio de dissolução intrínseca. Posteriormente, esses dados foram utilizados como referência nos estudos de caracterização dos complexos de inclusão. Os complexos binários utilizaram as ciclodextrinas naturais &#945;CD, &#946;CD e &#947;CD, e os ternários a &#946;CD e HP&#946;CD e adição de 1,0% de polímeros hidrossolúveis (povidona e copovidona). Os complexos foram secos em estufa e adicionalmente dois métodos de preparo co-evaporação e liofilização foram empregados para comparação e escolha do mais adequado. O estudo de caracterização dos complexos foi realizado através do método de solubilidade de fases, DSC e TGA. A constante de estabilidade, a eficiência de complexação e solubilidade sugeriram maior interação do fármaco com a &#946;CD. Nos complexos ternários, a utilização de copovidona foi mais efetiva que a povidona. Houve aumento da solubilidade quando os complexos foram preparados pelo método de liofilização. A melhor solubilidade foi alcançada pelos complexos BNZ:&#946;CD (0,84 mg/mL) e BNZ:&#946;CD:copovidona (0,86 mg/mL) preparados pelo método de liofilização. / The present study was aimed to obtain and characterize binary and ternary complexes of benznidazole (BNZ) with cyclodextrins and water-soluble polymers with the purpose to improve the solubility of drug. It was performed the physicochemical characterization of BNZ by differential scanning calorimetry (DSC), thermogravimetry (TGA), investigation of new crystalline forms and the definition of parameters for the intrinsic drug dissolution test of intrinsic dissolution. Subsequently, these informations were used as reference in the studies of characterization of the inclusion complexes. The binary complexes were prepared with the cyclodextrins &#945;CD, &#946;CD and &#947;CD and the ternary with &#946;DC and HP&#946;CD and addition of 1.0% of water-soluble polymers (povidone and copovidone). The complexes were dried in tray drayer and additionally two methods of preparation coevaporation and lyophilization were employeed for comparison and the best was selected. The characterization of the complexes was carried out by phase-solubility method, DSC and TGA. The constant of stability, the efficiency of complexation and solubity suggested higher interaction of the drug with the &#946;CD. In the ternary complexes, the use of copovidone was more effective in the solubility than to povidone. There was an increased of solubility when the complexes were prepared by lyophilization. To best solubility was achieved by the complexes BNZ:&#946;CD (0.84 mg/ml) and BNZ:&#946;CD:copovidone (0.86 mg/ml) prepared by lyophilization method.

The static equilibrium isothermal sorption of dioxane, ethyl acetate, and methanol vapors by POM polyoxometalates with the structure of buckyball (Mo132, Mo72Fe30) and torus (Mo138), and also polymer-salt compositions containing POM were studied. The changes in the chemical potentials of the components and the Gibbs energy of the interaction of POMs, polymers, and compositions with low molecular weight liquids are calculated. The Gibbs energies and entropies of interaction of the components of the POM – polymer systems are estimated. The stability of the POM structure before and after sorption was investigated by IR spectroscopy. It was established that all investigated POMs exhibit the highest sorption capacity for dioxane, the lowest for ethyl acetate. Mo132 exhibits maximum affinity for sorbates, Mo72Fe30 exhibits a minimum affinity, and Mo138 occupies an intermediate position. It was established that PVP and PVA adsorb methanol in significantly larger quantities compared with compositions containing POM. The same rule is observed for PVP-POM systems in the case of dioxane. PVA practically does not absorb dioxane, but the introduction of POM in films of polyvinyl alcohol leads to the appearance of the sorption ability of the film. For all compositions a decrease in the Gibbs energy of the interaction of components and an increase in entropy were found, which can be associated with loosening and partial destruction of the crystal structure of the POM when polymer chains are introduced into it. The structure of polyoxomolybdates was found to be stable in dioxane vapors, and is also preserved in polymer-salt compositions before and after sorption. / Изучена статическая равновесная изотермическая сорбция паров диоксана, этилацетата и метанола полиоксометаллатами ПОМ со структурой букибола (Mo132, Mo72Fe30) и тора (Mo138), а также полимерно-солевыми композициями, содержащими ПОМ. Рассчитаны изменения химических потенциалов компонентов и энергии Гиббса взаимодействия ПОМов, полимеров, композиций с низкомолекулярными жидкостями. Оценены энергии Гиббса и энтропии взаимодействия компонентов систем ПОМ – полимер. Методами ИК- спектроскопии исследована стабильность структуры ПОМ до и после сорбции. Установлено, что наибольшую сорбционную способность все исследованные ПОМ проявляют к диоксану, наименьшую – к этилацетату. Максимальное сродство к сорбатам проявляет Mo132, минимальное – Mo72Fe30, Mo138 занимает промежуточное положение. Установлено, что ПВП и ПВС сорбируют метанол в существенно больших количествах по сравнению с композициями, содержащие ПОМ. Такая же закономерность наблюдается для систем ПВП – ПОМ в случае диоксана. ПВС практически не поглощает диоксан, но введение ПОМ в пленки поливинилового спирта приводит к возникновению сорбционной способности пленки. Для всех композиций ПОМ -полимер обнаружено уменьшение энергии Гиббса взаимодействия компонентов и возрастание энтропии, которое может быть связно с разрыхлением и частичным разрушением кристаллической структуры ПОМ при внедрении в нее полимерных цепей. Обнаружено, что структура полиоксомолибдатов стабильна в парах диоксана, а также сохраняется в полимерно-солевых композициях до и после сорбции.

<p></p><p>This doctoral dissertation takes the reader through a journey where applied shear rheology and flow-velocimetry are used to understand the mesoscopic factors that control the flow behavior of three microstructured fluids. Three individual protocols that measure relative physical and mechanical properties of the flow are developed. Each protocol aims to advance the particular transformation of novel soft materials into a commercial product converging in the demonstration of the real the chemical, physical and thermodynamical factors that could potentially drive their successful transformation. </p> <p> </p> <p>First, this dissertation introduces the use of rotational and oscillatory shear rheometry to quantify the solvent evaporation effect on the flow behavior of polymer solutions used to fabricate isoporous asymmetric membranes. Three different A-B-C triblock copolymer were evaluated: polyisoprene-<i>b</i>-polystyrene-<i>b</i>-poly(4-vinylpyridine) (ISV); polyisoprene-<i>b</i>-polystyrene-<i>b</i>-poly(<i>N</i>,<i>N</i>-dimethylacrylamide) (ISD); and polyisoprene-<i>b</i>-polystyrene-<i>b</i>-poly(<i>tert</i>-butyl methacrylate) (ISB). The resulting evaporation-induced microstructure showed a solution viscosity and film viscoelasticity strongly dependent on the chemical structure of the triblock copolymer molecules. </p> <p> </p> <p>Furthermore, basic shear rheometry, flow birefringence, and advanced flow-velocimetry are used to deconvolute the flow-microstructure relationships of concentrated surfactant solutions. Sodium laureth sulfate in water (SLE₁S) was used to replicate spherical, worm-like, and hexagonally packed micelles and lamellar structures. Interesting findings demonstrated that regular features of flow curves, such as power-law shear thinning behavior, resulted from a wide variety of experimental artifacts that appeared when measuring microstructured fluids with shear rheometry.</p> <p> </p> <p>Finally, the successful integration of shear rheometry to calculate essential parameters to be used in a cost-effective visualization technique (still in development) used to calculate the dissolution time of polymers is addressed. The use of oscillatory rheometry successfully quantify the viscoelastic response of polyvinyl alcohol (PVA) solutions and identify formulations changes such as additive addition. The flow behavior of PVA solutions was correlated to dissolution behavior proving that the developed protocol has a high potential as a first screening tool.</p><br><p></p>