Academic literature on the topic 'Surfactantes'
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Journal articles on the topic "Surfactantes"
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Montaño, Fredina, and Juan Pereira. "Macromoléculas en sistemas de microemulsión." Ciencia e Ingeniería 43, no. 1 (2021): 115–28. http://dx.doi.org/10.53766/cei/2021.43.01.12.
Full textAbstract:
Las microemulsiones son sistemas surfactante-aceite-agua (SOW), termodinámicamente estables, con gran capacidad de solubilización y son capaces de reducir la tensión interfacial a valores ultra bajos. Por su parte, las macromoléculas anfipáticas están constituidas por unidades que se repiten, formando el esqueleto o columna, presentando restos hidrofóbicos e hidrofílicos, por lo que se comportan como surfactantes poliméricos. Esta clase de surfactantes presenta un comportamiento característico en interfases que difiere de surfactantes monoméricos. Estas especies se pueden emplear en sistemas SOW, y es posible además preparar microemulsiones con estos polímeros. Las interacciones surfactante-polímero que gobiernan estos sistemas son de particular interés, y afectan la actividad superficial de los surfactantes empleados, especialmente si el polímero se comporta como un polielectrolito. Por su parte, estos polímeros pueden ser de origen sintético o natural. En algunos casos, como celulosa o quitosano, el polímero es muy hidrofílico, por lo que es necesario modificar hidrofóbicamente su estructura para incrementar sus propiedades interfaciales. La presente revisión pretende evaluar diferentes sistemas SOW que involucren macromoléculas sintéticas y naturales, teniendo especial atención a sistemas de microemulsiones con surfactantes poliméricos, destacando las aplicaciones de los mismos y comportamiento en la interfase.
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Hernández, Inés C., and Juan Pereira. "Influencia de la formulación de espumas en medios porosos para procesos de recuperación mejorada de hidrocarburos." Revista Ingeniería UC 30, no. 1 (October 1, 2023): 3–13. http://dx.doi.org/10.54139/revinguc.v30i1.288.
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Los sistemas surfactantes presentan un alto interés en la industria petrolera por sus múltiples aplicaciones tecnológicas, en especial en los procesos de recuperación mejorada de hidrocarburos en los yacimientos. En el presente trabajo se desarrollaron sistemas unidimensionales micro porosos heterogéneos para medir la influencia de la inyección de espuma, empleando tres surfactantes a diferentes concentraciones (0,1; 1,0; 5,0; 10,0 % m/v). La mayor eficiencia de desplazamiento y recuperación se alcanzó con el surfactante SDS a la concentración de 5,0 %, al obtener un 70 % de rendimiento en extracción, en comparación con las demás concentraciones evaluadas. Este resultado demostró su aplicabilidad en el desarrollo de tecnologías nacionales para la recuperación mejorada en base a la inyección de espumas.
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Bravo, Belgica, Gerson Chávez, Nelson Márquez, Nacarid Delgado, Ana Cáceres, Milangel Luzardo, Iran Parra, Mariana Collins, and Azeneth Borja. "Comportamiento de agregación de noveles surfactantes de par iónico." Revista Bases de la Ciencia. e-ISSN 2588-0764 3, no. 2 (August 31, 2018): 1. http://dx.doi.org/10.33936/rev_bas_de_la_ciencia.v3i2.1145.
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Los ácidos alquilcarboxílicos pueden dar origen a la formación de una especie iónica con características anfifílicas que disminuye la tensión superficial de un sistema agua/aire. El tipo de contraión de estas especies juega un papel fundamental en las propiedades superficiales del compuesto. Se preparó una novedosa clase de surfactantes de par iónico (SPI) por neutralización de cantidades equimolares del ácido carboxílico con una base de tipo ciclohexilamina (cHACn) bajo condiciones suaves de reacción. Se estudió el comportamiento de agregación por tensión superficial. Los compuestos obtenidos disminuyeron la tensión superficial presentando baja concentración micelar crítica (CMC) y por tanto una mayor actividad superficial. La CMC de todos los compuestos estudiados disminuyó con la longitud de la cadena alquílica aniónica (n).
Palabras clave: ácidos alquilcarboxílicos, surfactantes de par iónico, comportamiento de agregación, tensión superficial.
ABSTRACT
The alkylcarboxylic acids can give origin to the formation of ionic species with amphiphilic characteristics that decreases the surface tension of a water/air system. The type of counterion of these species plays a fundamental paper in the surface properties of the compound. Novel class ion pair surfactants (IPS) were prepared by neutralization of equimolar amounts of carboxylic acid with a base of type cyclohexylamine (cHACn) though mild reaction conditions. The aggregation behavior through surface tension was studied. The compounds obtained reduced the surface tension presenting low critical micelar concentration (CMC) and therefore a greater surface activity. The CMC of all compounds studied decreased with the length of the anionic alkyl chain (n).
Key words: Alkylcarboxylic acids, ion pair surfactant, aggregation behavior, surface tension.
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Bravo, Bélgica, Gerson Chávez, Nelson Márquez, Nacarid Delgado, Ana Cáceres, Milangel Luzardo, Iran Parra, Mariana Collins, and Azeneth Borja. "Comportamiento de agregación de noveles surfactantes de par iónico." Revista Bases de la Ciencia. e-ISSN 2588-0764 3, no. 2 (August 31, 2018): 1. http://dx.doi.org/10.33936/rev_bas_de_la_ciencia.v3i2.1445.
Full textAbstract:
Los ácidos alquilcarboxílicos pueden dar origen a la formación de una especie iónica con características anfifílicas que disminuye la tensión superficial de un sistema agua/aire. El tipo de contraión de estas especies juega un papel fundamental en las propiedades superficiales del compuesto. Se preparó una novedosa clase de surfactantes de par iónico (SPI) por neutralización de cantidades equimolares del ácido carboxílico con una base de tipo ciclohexilamina (cHACn) bajo condiciones suaves de reacción. Se estudió el comportamiento de agregación por tensión superficial. Los compuestos obtenidos disminuyeron la tensión superficial presentando baja concentración micelar crítica (CMC) y por tanto una mayor actividad superficial. La CMC de todos los compuestos estudiados disminuyó con la longitud de la cadena alquílica aniónica (n).
Palabras clave: ácidos alquilcarboxílicos, surfactantes de par iónico, comportamiento de agregación, tensión superficial.
ABSTRACT
The alkylcarboxylic acids can give origin to the formation of ionic species with amphiphilic characteristics that decreases the surface tension of a water/air system. The type of counterion of these species plays a fundamental paper in the surface properties of the compound. Novel class ion pair surfactants (IPS) were prepared by neutralization of equimolar amounts of carboxylic acid with a base of type cyclohexylamine (cHACn) though mild reaction conditions. The aggregation behavior through surface tension was studied. The compounds obtained reduced the surface tension presenting low critical micelar concentration (CMC) and therefore a greater surface activity. The CMC of all compounds studied decreased with the length of the anionic alkyl chain (n).
Key words: Alkylcarboxylic acids, ion pair surfactant, aggregation behavior, surface tension.
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Celi, Jonathan, Franklin Gómez, and Bolívar Enríquez. "Análisis de la Tensión Interfacial Entre Dos Fluidos Inmiscibles con el Uso de Cuatro Surfactantes (Catiónico, No-Iónico), de la Arena Productora U Inferior del Campo Pindo." Revista Politécnica 47, no. 2 (April 30, 2021): 27–40. http://dx.doi.org/10.33333/rp.vol47n2.03.
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La aplicación de recuperación mejorada puede incrementar el factor de recobro en más de un 20% después de aplicar recuperación primaria y secundaria. Para recuperar ese petróleo remanente de los reservorios se puede inyectar fluidos con surfactantes, lo cual está dentro de la recuperación terciaria. En este trabajo, se examina las tensiones interfaciales y superficiales con el uso de cuatro surfactantes comerciales en diferentes concentraciones. Generando curvas para analizar la tensión interfacial entre dos fluidos inmiscibles (agua de inyección con surfactante y petróleo). La investigación se desarrolló en tres fases. En la primera, se analizaron las propiedades del agua (salinidad y concentración de sólidos disueltos), surfactante (pH y el análisis de espectrometría infrarroja) y petróleo (BSW y API). En la segunda fase se midieron las tensiones superficiales (TS) en una mezcla de agua de formación y surfactante a diferentes concentraciones para obtener la concentración micelar crítica (CMC), y en la tercera fase la medición de tensiones interfaciales (IFT) en los dos fluidos inmiscibles. Es decir, una mezcla de agua de inyección, surfactante y petróleo del campo Pindo. Las muestras de fluidos fueron proporcionadas por Petrosud Petroriva. Con los resultados, se procedió a generar curvas de Tensión superficial e interfacial Vs Concentración. El surfactante HALMX152805-2 de tipo no iónico con grupos funcionales de Alquil e Hidróxilo a una concentración del 0.3% en peso, tuvo la mayor reducción tanto en la CMC e IFT.
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Oliveira, Jorge M. de, and Lucia H. I. Mei. "Surfactantes reativos não-iônicos em polimerização em emulsão de látices de acetato de vinila - vinil neodecanoato: influência nas propriedades de barreira à água." Polímeros 19, no. 1 (2009): 22–30. http://dx.doi.org/10.1590/s0104-14282009000100009.
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A indústria de tintas é grande consumidora de látex obtido por polimerização em emulsão. Os surfactantes, essenciais à estabilidade do látex, exercem papel fundamental na produção e na aplicação destes polímeros. Contudo, podem também produzir efeitos adversos nas propriedades do produto, em razão de sua adsorção física às partículas de polímero. Os surfactantes não ligados podem migrar através do filme para as interfaces, formando agregados que podem aumentar a sensibilidade à água, afetando desta forma as propriedades de barreira. Um caminho promissor para minimizar este efeito dos surfactantes convencionais tem sido o uso de surfactantes polimerizáveis, ou reativos, que estão covalentemente ligados ao polímero e, desta forma, não podem ser dessorvidos e migrarem durante a formação do filme. Neste trabalho foram preparados látices de acetato de vinila - vinil neodecanoato (VeoVa 10®), estabilizados com surfactantes não-iônicos convencionais e reativos, e avaliado o desempenho dos filmes obtidos a partir destes látices. Os resultados demonstraram que o uso de surfactantes não-iônicos polimerizáveis pode, sob determinadas condições, trazer ganhos para as propriedades de barreira.
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RAMÍREZ-DUARTE, W. F., I. S. RONDÓN-BARRAGÁN, and P. R. ESLAVA-MOCHA. "Surfactantes asociados a herbicidas: Efectos sobre organismos acuáticos." Orinoquia 9, no. 2 (September 1, 2005): 45–59. http://dx.doi.org/10.22579/20112629.142.
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Titulo en ingles: Surfactants associated to herbicides: Effects in aquatic organisms.RESUMEN: Los surfactantes son compuestos químicos adyuvantes, muchos de los cuales son utilizados para mejorar la efectividad de sustancias biológicamente activas como herbicidas o plaguicidas. La mayoría actúa en las interfases de fluidos y tiene una estructura bipolar con porciones hidrofílicas e hidrofóbicas que les permite interactuar con las superficies celulares y con las membranas biológicas en general, causando efectos sobre la tensión superficial y la movilización de moléculas entre los medios extra e intracelular y tal vez lesiones directas en las membranas epiteliales de órganos vitales de animales acuáticos como las de las branquias. Esta revisión ha sido motivada por la necesidad de indagar sobre las consecuencias de los compuestos acompañantes de herbicidas para el control de cultivos de coca y amapola, los cuales se usan sin advertir el posible efecto de tales sustancias; pudiendo tener secuelas significativas sobre el ambiente y la salud humana y animal.Palabras clave: Surfactantes, adyuvantes, herbicidas, toxicología acuática.ABSTRACT: The surfactants are chemical adjuvant compounds, many of which are used to improve the effectiveness of biologically active substances like herbicides or plaguicides. Most of them act on the interphases of fluid and have a bipolar structure with hydrophilic and hydrophobic portions that allow them to interact with both the cellular sur faces and biological membranes in general, causing effects on the surface tension and the molecule mobilization between the extracellular and intracellular environment. On the other hand, direct injuries to epithelial membranes of vital organs for aquatic organisms like gills do not discard. This review has been motivated by the necessity to investigate on the consequences of adjuvant compounds of herbicides for the control of cocaine and poppy crops, which are used without noticing the possible effect of such adjuvant compounds; they may have significant sequels on either the environment as well as human and animal health.Keywords: Surfactants, adjuvants, herbicides, aquatic toxicology
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Nagles, Edgar O., Roxana Ríos, John Hurtado, and Verónica Arancibia. "Estudio electroquímico de Rojo de Pirogalol (RP) en presencia de surfactantes de diferente carga." Ingenium 6, no. 13 (September 30, 2012): 65. http://dx.doi.org/10.21774/ing.v6i13.89.
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La interacción de Rojo de Pirogalol (RP) con los surfactantes dodecil sulfato de sodio (SDS) y bromuro de cetilpiridinio (CPB) de carga negativa y positiva respectivamente fue estudiada por voltamperometría cíclica a pH 2,0 y 8,0 sobre electrodos serigrafiados de carbono. Su interacción y localización en los surfactantes fue estudiada por los cambios sufridos en las corrientes de pico a diferentes concentraciones de surfactantes observándose efectos catalíticos de corriente.
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Cavalcante, Reinaldo Fontes, Glória Maria Marinho, and Barbara Chaves A. Barbosa. "Impactos Ambientais do Alquil benzeno Sulfonado Linear." HOLOS 4 (August 2, 2014): 135. http://dx.doi.org/10.15628/holos.2014.1247.
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O uso de surfactantes tem crescido em todo o planeta níveis exponenciais e o alquil benzeno sulfonado linear(LAS) é o surfactante aniônico mais utilizado em todo o globo com uma produção anual de 2,8 milhões de toneladas. Devido a isso cresce a preocupação com os efeitos adversos que a disposição inadequada desta substância acarreta para o meio terrestre e o meio aquático. A ação nociva, do surfactante LAS, a vida da biota destes ambientes se dão principalmente devido a ruptura da membrana celular através da interação com os componentes lipídicos, e a reação com enzimas fundamentais para o funcionamento das células, efeitos estes intensificados pela sua concentração. Nos ambientes aquáticos o LAS pode acarretar alterações nas taxas de oxigenação natural,deficiência na reprodução de peixes e invertebrados, eutrofização e situações de escassez qualitativa de recursos hídricos. foi observado que os efluentes de origem doméstica são os principais contribuintes do Alquil benzeno sulfonado Linear(LAS) e que a degradação biológica do LAS pode ocorrer a níveis de eficiência que chegam a 80% e ainda que pode ser potencializada com a ação combinada com processos físico químicos. Concentrações abaixo de 0,29mg/L reduzem seus efeitos nocivos sendo o tratamento deste surfactantes aniônico um fator estratégico para o incremento da oferta hídrica e da preservação dos recursos naturais da região.
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Bernal Samaniego, Cesar Augusto, and Karina Rodríguez Mora. "Estudio de dispersiones de un sistema de parafina-agua-surfactante." Revista Ingeniería 29, no. 1 (December 13, 2018): 80–92. http://dx.doi.org/10.15517/ri.v29i1.33529.
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Se estudió el sistema de parafina-aceite-surfactante con la finalidad de obtener emulsiones que tuvieran la capacidad de ser autodispersables en agua y se realizaran con un método de mezclado de baja energía. Se realizó un primer barrido de formulación con diferentes surfactantes de la línea tween y span, así como las mezclas de los mismos, para la obtención de emulsiones de tipo W/O (agua en aceite, por sus siglas en inglés). Seguidamente se realizó un segundo barrido de formulación variando el HLB y/o ligeramente el porcentaje de surfactante o el agua empleadas. Posteriormente, se estudió el tamaño de gota y la estabilidad, demostrando que en los sistemas estudiados se obtienen emulsiones más estables con altas cantidades de surfactante y un HLB de 8.
Dissertations / Theses on the topic "Surfactantes"
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Senra, Tonimar Domiciano Arrighi. "N,N,N-trimetilquitosana e N-(2-hidróxi)-propil-3-trimetilamônio quitosana: preparação, caracterização e estudo de suas interações com decanossulfonato de sódio." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/75/75134/tde-20052015-154551/.
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O presente trabalho estudou duas vias reacionais para a preparação de derivados cationizados de quitosana (QCat), sendo que a N-metilação extensiva via reação de quitosana com iodometano (CH3I) resultou em N,N,N-trimetilquitosana (TMQ) enquanto que a reação de quitosana com cloreto de glicidiltrimetilamônio (CGTMA) produziu N-(2-hidroxi)-propil-3-trimetilamônio quitosana (HPTAQ). Planejamento fatorial completo 23 foi aplicado para analisar os efeitos das condições reacionais sobre o rendimento das reações (R) e as características de TMQ e HPTAQ. As características estruturais da quitosana de partida e seus derivados foram analisadas por espectroscopias na região de infravermelho (FTIR) e de ressonância magnética nuclear de hidrogênio (RMN-1H), sendo que esta última também foi utilizada para determinar os graus médios de acetilação (GA), de quaternização (GQ) e de substituição (GS) de quitosana, TMQ e HPTAQ, respectivamente. Viscosimetria capilar foi utilizada para determinar a viscosidade intrínseca ([η]) de quitosana, TMQ e HPTAQ, permitindo estimar a ocorrência de despolimerização e sua relação com as condições reacionais. Todas as amostras de TMQ foram solúveis em água e o valor de GQ variou no intervalo 21,0 - 67,0%; a [η] variou entre 13,7 mL/g - 213,0 mL/g e o rendimento da reação atingiu até 82,0%, sendo que entre as variáveis analisadas a concentração de hidroxido de sódio e excesso de CH3I são as mais relevantes. Quanto às amostras de HPTAQ, apenas aquelas com GS > 12,0% foram solúveis em água,GS ficou no intervalo 1,0 % - 45,5%; [η] variou entre 283,0 mL/g - 446,0 mL/g e o rendimento não foi superior a 33,0%, e entre as variáveis analisadas, temperatura e excesso de CGTMA foram as mais importantes na produção de HPTAQ. As amostras TMQ2 GQ = 46,0%; [η] = 290,0 mL/g) e HPTAQ6 GS = 33,0%; [η] = 293,0 mL/g) foram empregadas em estudo visando a formação de complexos surfactante/polieletrólito (CSP) com decanossulfonato de sódio (DS). As propriedades condutimétricas e tensiométicas dos TMQ2, HPTAQ6 e CSP\'s foram estudadas e mostraram que todos apresentam atividade interfacial (γ <= 52,0 mN.m-1), além de elevado valor de módulo de elasticidade (E >= 31,0 mN.m-1), indicando que as espécies analisadas geram filmes interfaciais com boas propriedade mecânicas e por isso podem ser aplicados como agentes estabilizantes de emulsões. As emulsões do tipo óleo/água preparadas pela incorporação de QCat (TMQ ou HPTAQ) ou de CSP (TMQ/DS ou HPTAQ/DS) foram estáveis por mais de 4 meses, conforme avaliado por medidas de fluorescência e de turbidez.In this work were studied two different methods for preparing cationized derivatives of chitosan (ChCat), a consisted extensive N-methylation by chitosan reaction with iodomethane (CH3I) resulted in N,N,N-trimethylchitosan (TMCh), and other a reaction of chitosan with chloride glycidyltrimethylammonium (GTMAC) resulted in N-(2-hydroxy)-propyl-3-trimethylammonium chitosan (HPTACh). A complete factorial design (23) was used to analyze the influence of reaction conditions on the yield of the reaction (R) as well as the characteristics of TMCh and HPTACh produced. The structure of chitosan pattern and its derivatives were characterized by infrared spectroscopy (IR) and nuclear magnetic resonance (1H-NMR), considering that the latter was also used to determine the average degree of acetylation (DA), quaternization (DQ) and substitution (DS) of chitosan, TMCh and HPTACh, respectively. Capillary viscometry was used to determine the intrinsic viscosity ([η]) of chitosan, TMCh and HPTACh, allowing to estimate the occurrence of depolymerization and its relationship with the reaction conditions. All samples of TMCh were soluble in water and it was found that DA ranged as 21.0% - 67.0%; the [η] ranged as 13.7 mL/g - 213.0 mL/g and the yield reaction was up to 82.0%, among the variables studied, the concentration of sodium hydroxide and excess CH3I were the most relevant. The HPTACh samples were soluble in water with DS > 12.0%, DS ranged as 1.0% - 45.5%; the [η] ranged as 283.0 mL/g - 446.0 mL/g and the yield was lower than 33.0%, among the variables studied temperature and excess CGTMA were the most important in the production of HPTACh. Among the reaction conditions studied for the synthesis of TMCh the best condition was 2, while for HPTACh the best condition was 6. The samples TMCh2 DQ = 46.0%, [η] = 290.0 ml/g) and HPTACh6 DS = 33.0%, [η] = 293.0 mL/g) were used in a study aiming at the formation of surfactant/polyelectrolyte complex (SPEC) with sodium 1-decanessulfonate (SD). The conductivity and surface tension properties of TMCh2, HPTACh6 and SPEC\'s have been studied and show that all have interfacial activity (γ <= 52.0 mN.m-1), and high value of elasticity modulus (E >= 31.0 mN.m-1), indicating that all species generate interfacial film with good mechanical property and thus can be applied as a stabilizing agent in emulsions emulsions oil/water that were prepared by incorporating ChCat synthesized and SPEC\'s in their formulations, they were stable for more than 4 months, as evaluated by fluorescence and turbidity measurements.
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Carolei, Luciano. "Determinação de surfactantes e água em formulações de sabonetes líquidos e shampoos por infravermelho por transformada de Fourier (FTIR) utilizando a técnica de reflectância total atenuada (ATR)." Universidade de São Paulo, 2005. http://www.teses.usp.br/teses/disponiveis/46/46133/tde-29102007-143925/.
Full textAbstract:
Demonstrou-se pela primeira vez que é possível determinar surfactantes e água em formulações de Sabonetes Líquidos (SL) e Shampoos (SH), direta e simultaneamente pela técnica de infravermelho por transformada de Fourier (FTIR) acoplada à uma cela de reflectância total atenuada (ATR). Tradicionalmente, a principal aplicação do infravermelho médio (2,50 - 15,0 µm) é a identificação de compostos orgânicos. O desenvolvimento de novos acessórios, principalmente de ATR, os avanços na área de microinformática e de métodos quimiométricos, vem viabilizando as análises quantitativas rápidas com excelentes resultados mesmo em meio aquoso. A determinação simultânea de surfactantes em formulações por FTIR-ATR é investigada em detalhes nesta tese. Dentre os surfactantes utilizados, o Lauril Éter Sulfato de Sódio (LESS) e a Cocoamidopropil Betaína (CAPB) são comuns em ambas as formulações, sendo a Coco Dietanolamida (CDEA) empregada em shampoo e o Alquilpoliglicosídeo (APG) em sabonete líquido. Espectros de absorbância de amostras padrão e de verificação foram adquiridos na região do infravermelho médio (800-1600 e 1900-3000 cm-I). Para a regressão de mínimos quadrados clássicos (CLSR), selecionou-se 200 números de onda, enquanto que para a regressão de mínimos quadrados inversos (ILSR), apenas 10. Nas regressões de componentes principais (PCR) e de mínimos quadrados parciais (PLSRI e PLSR2), utilizaram-se de 300 à 1100 números de onda. Dois conjuntos de amostras padrão foram preparados, o primeiro, contendo 27 misturas padrão, foi estudado somente pelos métodos CLSR e ILSR, enquanto que o segundo conjunto, contendo 48 amostras padrão, foi avaliado por todos os métodos mencionados acima. A seleção das regiões de quantificação favoreceu números de onda dos componentes minoritários CAPB, APG e CDEA e resultados satisfatórios foram encontrados para 18 amostras de shampoo e sabonete líquido. Interferentes como NaCl e perfume foram incluídos no segundo conjunto e os métodos PCR e PLSR proporcionaram melhores resultados. Os erros relativos (RSEP%) para água (correspondendo a 84-88% do produto) e LESS (6-10%) não excederam 1%; para CAPB (<3%) e CDEA (<2%), o RSEP% situou-se entre de 2-4% e para APG (<3%), não excedeu 5%. Avaliações do processo de normalização, repetibilidade, vulnerabilidade a interferentes (perfumes), redução no número de padrões de calibração foram conduzidos, encontrando-se resultados satisfatórios para todos os casos, com erro relativo inferior à 5,0%. Um dispositivo simples para injeção direta da amostras no acessório de ATR foi construído, permitindo aumentar a freqüência analítica de 20 para 60 análises por hora.It is demonstrated for the first time that the principal constituents of a shampoo as well as of a liquid soap -three surfactants and water- can be determined directly, simultaneously and quickly in undiluted samples by Attenuated Total Reflection Fourier Transform Infrared (ATR-FTIR) spectroscopy in the middle infrared region, despite the broad absorption bands ofthe solvent. The main application of the middle infrared (2,50 - 15,0 µm) was the identification of organic compounds. The development of new accessories, such as ATR, and the advance of computers and chemometrics, extended the technique to quantitative analysis, with excellent results. The simultaneous determination of surfactants in shampoos and liquid soap formulations by FTIRA TR is investigated in detail in this thesis. Two of the surfactants, sodium lauryl ether sulfate (LESS) and cocoamidopropyl betaine (CAPB) are common to both formulations; alkylpolyglucoside (APG) is the third surfactant of the liquid soap and cocodiethanolamide (CDEA), the corresponding ingredient of the shampoo. Absorbance data of the undiluted verification samples and calibration standards was collected in the middle infrared region of the spectrum (800-1600 and 1900-3000 cm-1). Five methods of multivariate quantification were compared: Classical Least Squares Regression (CLSR), where absorbance data measured at 200 wavenumbers was processed, Inverse Least Squares Regression (ILSR), were data at 10 selected wavenumbers was analyzed, Principal Components Regression (PCR), and Partial Least Squares Regression, which has two different approaches, PLSR1 and PLSR2. Two sets of standard samples were prepared for the method calibration. The first one, consisting of 27 standard mixtures, was evaluated by the CLSR and ILSR methods; a second set, with 48 standards, was evaluated by all the methods mentioned above. Potential interfering, such as NaCI and perfume, were inc\\uded in this second set. By favoring wavenumbers where absorption bands of the minor components (CAPB in both formulations, APG in the liquid soap and CDEA in the shampoo) are more intense, good results were obtained for 18 simulated samples of shampoo and 18 samples of liquid soap. For the second set, PCR and PLSR methods were most favorable; relative errors (RSEP%) for water (major component, 84-88%) and LESS (6-10%) did not exceed 1%; for CAPB (<3%) and CDEA(<2%), RSEP% of 2-4% were observed, and for APG(<3%), 5% was not exceeded. Tests for repeatability, normalization performance evaluation, effect of interferents presented favorable results. A simple device for direct sample injection was designed and evaluated. It permitted an increase ofthe analytical frequency from 20 to 60 samples per hour.
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Ramos, Lierge [UNESP]. "Estudos biofísicos da Hemoproteína extracelular de Amynthas gracilis (HbAg) na ausência e na presença de surfactantes." Universidade Estadual Paulista (UNESP), 2017. http://hdl.handle.net/11449/151572.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
As hemoglobinas constituem um grupo de proteínas que desempenham um papel vital nos organismos. Suas propriedades intrínsecas, assim como a sua relação estrutura-atividade, envolvem fenômenos tais como a cooperatividade e afinidade por ligantes específicos, como o oxigênio, que estão associados a uma variedade de processos que viabilizam a vida. As hemoproteínas, em especial as hemoglobinas de anelídeos têm sido objeto de estudo de diferentes grupos de pesquisa, devido a sua alta estabilidade oligomérica, resistência à oxidação, alta cooperatividade e afinidade por ligantes específicos, apresentando um alto potencial em aplicações biotecnológicas como, por exemplo, substituto sanguíneo. Estudos sobre a caracterização estrutural e a determinação da estabilidade de hemoproteínas na presença de surfactantes, por meio de várias técnicas como absorção ótica, emissão de fluorescência, CD (Dicroísmo Circular) e espalhamento de luz podem trazer informações sobre esta classe de proteínas, principalmente sobre o mecanismo de oxidação, dissociação e desnaturação. Desta forma, no presente projeto de pesquisa objetivou realizar a caraterização biofísica da hemoglobina extraída de Amynthas gracilis (HbAg) na presença de surfactantes iônicos (SDS e CTAC) nos valores de pH 5,0 e 7,0. Os resultados nos mostram que ambos os surfactantes são capazes de interagir fortemente com a HbAg, sendo que o pH do meio influência diretamente na intensidade da interação proteína-surfactante. O SDS em pH 5,0 interage fortemente com a HbAg formando precipitados de complexo proteína-surfactante, podendo ser observados em baixas concentrações de SDS (0,01 – 0,2 mmolL-1). Enquanto que para o CTAC ocorre uma forte interação entre o surfactante e a HbAg em pH 7,0 em uma faixa de concentração de 0,01 – 0,07 mmolL-1. A formação de agregados nestes sistemas provavelmente ocorre em função do ponto isoelétrico (pI) da HbAg ser ácido (6,0 ±3), assim como o de outras Hb extracelulares, como resultado de uma forte interação eletrostática. As medidas espectroscópicas indicam que com o aumento da concentração dos surfactantes ocorre a ressolubilização dos agregados. Os resultados obtidos neste estudo demonstraram que o SDS e o CTAC promovem o processo de oxidação/dissociação da HbAg em baixas concentrações e que nas concentrações máximas de surfactantes utilizadas neste trabalho o processo de desnaturação da HbAg não é completo.
Hemoglobins are a group of proteins that play a vital role in organisms. Their intrinsic properties, as well as their structure-activity relationship, involve phenomena such as cooperativity and affinity for specific ligands, such as oxygen, which are associated with a variety of processes that make life possible. Hemoproteins, especially hemoglobins of annelids have been studied by different research groups, due to their high oligomeric stability, resistance to oxidation, high cooperativity and affinity for specific ligands, presenting a high potential in biotechnological applications, for example, a blood substitute. Studies on the structural characterization and determination of hemoprotein stability in the presence of surfactants by optical absorption, fluorescence emission, CD and light scattering can bring information about this class of proteins, mainly on the mechanism of dissociation and denaturation. Thus, in the present master's project the main objective was to perform biophysics characterization studies, with the hemoglobin extracted from the annelid of Amynthas gracilis (HbAg) in the presence of ionic surfactants (SDS and CTAC) at pH values 5,0 and 7,0. The results show that both surfactants are capable of interacting strongly with HbAg, and the pH of the medium directly influences the intensity of the protein-surfactant interaction. SDS at pH 5.0 strongly interacts with HbAg forming precipitates of protein-surfactant complex, can be observed with low concentrations of SDS (0.01 - 0.2 mmolL -1). While for CTAC a strong interaction between surfactant and HbAg occurs at pH 7.0 in a concentration range of 0.01-0.07 mmolL-1. The formation of aggregates in these systems probably occurs as a function of the isoelectric point (pI) of HbAg being acid (6.0 ± 3), as well as that of other extracellular Hb, as a result of a strong electrostatic interaction. This study showed that SDS and CTAC promote the oxidation/dissociation process of HbAg at low concentrations and that at the maximum concentrations of surfactants used in this work the denaturing process of HbAg is not complete.
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Picone, Carolina Siqueira Franco 1983. "Formação de nanopartículas por associação de biopolímeros e surfactantes = Formation of nanoparticles by biopolymer - surfactant association." [s.n.], 2012. http://repositorio.unicamp.br/jspui/handle/REPOSIP/254194.
Full textAbstract:
Orientador: Rosiane Lopes da CunhaTexto em português e inglês
Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos
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Resumo: As nano partículas possuem grande potencial para a liberação controlada de bioativos, porém ainda são pouco exploradas na área de alimentos. Neste trabalho foi estudada a formação de nanopartículas a partir da autoagregação de surfactantes, associação surfactante-polissacarídeo e complexação eletrostática entre diferentes polissacarídeos, no caso, quitosana e gelana. A compreensão das interações moleculares responsáveis pela formação das partículas e o conhecimento das variáveis que afetam sua formação permitem predizer e controlar suas propriedades. Tais interações dependem fortemente das características de cada macromolécula, como flexibilidade, estado conformacional e densidade de cargas que são diretamente afetadas pelas condições físico-químicas do meio como pH, força iônica e temperatura. Por isso, este trabalho foi dividido em três etapas. (I) Inicialmente foi avaliado o comportamento em solução dos polissacarídeos utilizados posteriormente para a formação de complexos. Os efeitos do pH e da temperatura nas características reológicas e no estado conformacional de soluções puras de gelana e quitosana foram estudados. A agregação da gelana foi mais sensível às alterações do meio que a quitosana. (II) Na segunda etapa, nanopartículas foram formadas por autoassociação de polissorbatos na presença de quitosana. A influência do comprimento da cauda hidrofóbica do surfactante e do pH do meio nas propriedades das partículas foi estudada por espalhamento de luz, reologia, condutivimetria e microscopia de luz polarizada. O tamanho e estrutura das partículas formadas pelo surfactante de menor cadeia hidrofóbica foram mais favoráveis à associação com a quitosana. O pH do meio (3,0 ou 6,7) não influenciou de maneira significativa as características das partículas. O efeito da concentração de quitosana na estrutura e tamanho de partículas foi analisado. Maiores concentrações levaram a viscosidades mais elevadas, impedindo a agregação das micelas e formando partículas menores. (III) No terceiro estudo, nanopartículas foram obtidas pela complexação eletrostática de gelana e quitosana. Os efeitos da razão de concentração de cada polissacarídeo, do tempo de estocagem a 25 °C e da presença de um surfactante nãoiônico (polissorbato) no tamanho, carga e quantidade de partículas formadas foram avaliados. Devido à menor densidade de carga e flexibilidade da gelana, maior quantidade deste polissacarídeo foi necessária para obtenção de partículas neutras. De forma geral, as partículas apresentaram aumento de tamanho ao longo das primeiras 100 horas após o preparo e não foram observadas mudanças significativas das propriedades das partículas devido à adição de surfactante. O método de preparo das amostras também foi estudado. Partículas preparadas pela mistura das soluções de polissacarídeos em dois passos foram consideravelmente maiores que as preparadas pela mistura em uma única etapa. Este trabalho confirmou a possibilidade de formação de nanopartículas promissoras para a encapsulação de bioativos em alimentos a partir da associação de biopolímeros e surfactantes, cujas propriedades poderiam ser moduladas em função da composição e condições de processo
Abstract: Nanoparticles are promising vehicles for bioactive delivery, but their potential has not been fully explored by the food industry. This work studied the formation of nanoparticles by self-assembly of surfactants, polysaccharide-surfactant association, and electrostatic complexes formed by different polysaccharides, especially chitosan and gellan gum. The knowledge of molecular interactions and the variables that affect particle formation allows predicting and controlling the properties of nanoparticles. These interactions depend on the characteristics of each macromolecule such as conformation, charge density and flexibility, which are affected by the physicol-chemical properties of the solution, such as pH, ionic strength and temperature. This work was divided in three parts: (I) Firstly it was studied the behaviour of each polysaccharide alone. The influence of the pH and temperature on the rheological properties and structural conformation of the pure gellan and chitosan samples was determined. Gellan aggregation was more strongly affected by such variables than chitosan. (II) In the second part, nanoparticles were obtained by polysorbate-chitosan association. The effect of the length of surfactant tail and the solution pH on the particle properties was studied by dynamic light scattering, rheological and conductivity measurements and polarizing microscopy. The size and structure of nanoparticles composed by the shorter surfactant were more appropriated to chitosan assembly. The pH (6.7 or 3.0) did not affect significantly the particle properties. The effects of chitosan concentration on particle structure and size were studied. Greater chitosan concentration led to smaller particles due to the increase in viscosity values which prevented micelles aggregation. (III) In the third study nanoparticles were produced by electrostatic complexation of chitosan and gellan gum. Particle size, charge density, stability and complexes number were evaluated as a function of polysaccharide concentration, chitosan:gellan ratio and the presence of a non-ionic surfactant. Due to the stiffness and low charge density of gellan gum, a greater amount of such polysaccharide was necessary to obtain neutral particles. Overall particles showed an increase in size during 100 hours of storage at 25 °C, but no significant changes on particle properties were observed due to surfactant addition. The methodology of particle preparation was also evaluated. Particles prepared by 2 mixing steps were markedly larger than those prepared by mixing polysaccharides in a single step (all together). This work showed that it is possible to produce nanoparticles with promising application on bioactive delivery by biopolymer-surfactant association, since their properties could be modulated as a function of composition and process conditions
Doutorado
Engenharia de Alimentos
Doutor em Engenharia de Alimentos
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Segundo, João de Deus Pereira de Moraes 1988. "Influência da adição de surfactantes em fibras altamente alinhadas de poli (caprolactona) obtidas por eletrofiação." [s.n.], 2015. http://repositorio.unicamp.br/jspui/handle/REPOSIP/265717.
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Orientador: Marcos Akira D'ÁvilaDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica
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Resumo: A eletrofiação é uma das principais técnicas para produzir fibras poliméricas ultrafinas na escala nano e submicrométrica. A poli ('épsilon'-caprolactona) (PCL) é um polímero sintético biodegradável bastante utilizado na área médica. Fibras de PCL obtidas por eletrofiação formam mantas porosas propícias para aplicações biomédicas como na engenharia tecidual. Em algumas aplicações as fibras alinhadas de PCL são de interesse, pois conferem melhorias em determinadas propriedades quando comparadas com fibras aleatórias. A PCL é considerada um polímero moderadamente hidrofóbico e a eletrofiação aumenta a hidrofobicidade das mantas. Os surfactantes têm a capacidade de modificar a superfície das fibras poliméricas aumentando a sua molhabilidade. Este trabalho versa sobre a influência da adição de surfactantes catiônico (CTAB), aniônico (SDS) e não-iônico (Triton X-100) na morfologia e no alto alinhamento de fibras de PCL obtidas por eletrofiação com coletor rotativo. Preparou-se solução de PCL contendo clorofórmio e acetona como solventes. As concentrações em massa de surfactantes utilizadas foram: 0,05; 0,1; 0,5; 1,0 e 1,5 wt%. As soluções foram caracterizadas através de medições de tensão superficial, condutividade elétrica e reologia. As morfologias das fibras foram analisadas com Microscópio Eletrônico de Varredura (MEV) juntamente com o software imageJ e o plugin OrientationJ. As fibras foram caracterizadas quanto às propriedades térmicas (DSC), análise química (FTIR) e molhabilidade (ângulo de contato). Através dos resultados obtidos, observou-se que a condutividade elétrica das soluções foi aumentada de acordo com o tipo de surfactante. A reologia foi alterada com os tipos e as concentrações, enquanto a tensão superficial não apresentou mudança significativa com a adição dos surfactantes. Os surfactantes CTAB e SDS alteraram o alinhamento das fibras de PCL e, dependendo da concentração, melhoraram a uniformidade dos diâmetros das fibras. Os surfactantes foram capazes de melhorar a molhabilidade das mantas, enquanto as propriedades térmicas foram mantidas
Abstract: The electrospinning is one of the main techniques to produce ultrafine polymeric fibers in the nano and submicron scale. Poly ('épsilon'-caprolactone) (PCL) is a biodegradable synthetic polymer widely used in the medical field. Electrospun PCL fibers form porous mats favorable for biomedical applications such as in tissue engineering. PCL aligned fibers are of interest since it expand the applications of these fibers and confer improvements in certain properties when compared with random fibers. PCL considered a moderately hydrophobic polymer and the electrospinning increases the hydrophobicity of the mats. Surfactants have the ability to modify the surface of polymeric fibers increasing its wettability. This work is concerned with the study of the effects of adding cationic (CTAB), anionic (SDS) and nonionic (Triton X-100) surfactants in the morphology and alignment PCL fibers obtained by electrospinning used a rotating collector. Poly ('épsilon'-caprolactone) (PCL) solutions with chloroform and acetone as solvent were prepared and different concentrations of surfactants were used: 0.05; 0.1; 0.5; 1.0; and 1,5 wt% in mass. Solutions characterized by measurements of surface tension, electric conductivity and viscosity. The morphology of the fibers analyzed by Scanning Electron Microscopy (SEM) together with the ImageJ software and OrientationJ plugin. The fibers characterized by differential scanning calorimetry (DSC), infrared spectroscopy (FTIR) and wettability (contact angle). Through the results obtained, the electrical conductivity of the solutions increased according to the type of surfactant. The rheology changed with the types and concentrations, while the surface tension did not change significantly with the addition of surfactants. The presence of surfactants CTAB and SDS influence the alignment of the PCL fibers, and depending on the concentration, improve the uniformity of fiber diameters. The surfactants were able to improve the wettability of mats, while the thermal properties maintained
Mestrado
Materiais e Processos de Fabricação
Mestre em Engenharia Mecânica
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Viana, Rommel Bezerra. "Espectroscopia de infravermelho de cristalitos de surfactantes." Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/75/75132/tde-23062008-094327/.
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O objetivo deste trabalho é estudar o nível de organização dos cristalitos de surfactantes aniônico, catiônico e zwiteriônico com o aumento na densidade destas moléculas sobre um cristal de germânio. As análises foram realizadas por espectroscopia de infravermelho com transformada de Fourier acoplada à técnica de reflexão total atenuada (FTIR-ATR). Este estudo apresenta importantes aspectos na organização do dodecilsulfato de sódio (SDS), do N-hexadecil-N,N-dimetil-3-amônio-1-propanosulfato (HPS), do brometo de hexadeciltrimetilamônio (CTAB) e do brometo de dodeciltrimetilamônio (DTAB). No SDS é observado um deslocamento de 1.7 cm-1 para valores de maior frequência na banda de estiramento assimétrico do CH2, vass (CH2), enquanto que é observado um deslocamento de 0.9 cm-1 na banda de estiramento simétrico, vsim (CH2). Este deslocamento para valores de maior frequência nas bandas de estiramento está associado com um aumento na desorganização da cadeia alifática com o aumento na densidade de moléculas sobre o elemento de ATR. A banda de deformação angular do CH2, δ(CH2), apresenta um valor em 1468 cm-1 que é também um indicativo de desorganização. No CTAB não é observado variações acentuadas nos valores das frequências vibracionais. Na banda vass (CH2) do DTAB é observado um deslocamento de 4.5 cm-1 para valores de menor frequência. Embora seja observado valores próximos de 2920 cm-1 para a banda vass (CH2), que é um indicativo do estado líquido de surfactantes, o que é observado nesse estudo são cristalitos de DTAB. O deslocamento da banda vsim (CH2) do DTAB é da ordem de 2 cm-1. Estas mudanças nas bandas vass (CH2) e vsim (CH2) são um indicativo da diminuição nas conformações gauche e um aumento nas conformações trans ao longo da cadeia alifática. O valor da freqüência em torno de 1472 cm-1 para a banda δ(CH2) é também um indicativo de uma maior organização na cadeia de CH2 do DTAB. Para o HPS é observado um deslocamento de 2.6 e 2.7 cm-1 para valores de maior frequência nas bandas vass (CH2) e vsim (CH2), respectivamente. A banda δ(CH2) do HPS apresenta um deslocamento de 4 cm-1 para valores de maior frequência. A variação nas bandas vass (CH2), vsim (CH2), e δ(CH2) ressalta o aumento na desorganização da cadeia alifática com o aumento na densidade de moléculas de HPS sobre o germânio.The objective of this work is study the order level of anionic, cationic and zwitterionic surfactants with the increase of their density packing on the surface of a germanium element. The analyses were performed by a Fourier transform infrared-attenuated total reflection spectroscopy. This study shows important insights on the conformational order of sodium dodecyl sulfate (SDS), N-hexadecyl-N-N -dimethyl-3-ammonio-1-propane-sulfonate (HPS), hexadecyl-trimethylammonium bromide (CTAB) and dodecyl trimethylammonium bromide (DTAB). It is observed a shift of 1.7 and 0.9 cm-1 to higher frequency values of the CH2 asymmetric (vass (CH2)) and symmetric (vsim(CH2)) stretching bands for the SDS molecules, respectively. The latter shift to higher frequency values is associated with the disorder of the aliphatic chain due to the increase of density packing of SDS molecules on the germanium element. The CH2 scissoring band [δ (CH2)] shows a value in 1468 cm-1, which is also an indicative of conformational disorder. It is not observed any accentuated change on the vibrational frequency values of the CTAB molecules. The vass (CH2) band of the DTAB molecules is shifted 4.5 cm-1 to lower frequency values. Although it is observed values near 2920 cm-1 for the vass(CH2) band, indicating a surfactant liquid phase, it is shown in this study that there are indeed DTAB crystallites. The shift of DTAB vsim(CH2) band is around 2 cm-1. These changes in vass(CH2) and vsim(CH2) band are an indicative of a decrease in gauche conformations and an increase in all-trans conformations over the aliphatic chain. The frequency value around 1472 cm-1 for the δ(CH2) band is also an indicative of the order in CH2 chain of DTAB. It is observed a shift of 2.6 and 2.7 cm-1 to higher frequency values of vass (CH2) and vsim(CH2) bands of the HPS molecule, respectively. The δ(CH2) band of the HPS molecule presents a shift of 4 cm-1 to higher frequency values. These variations in vass (CH2), vsim(CH2), and δ(CH2) bands stand out the disorder of the aliphatic chain due to the increase of the density packing for the HPS molecules on the germanium surface.
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Alves, Fernanda Rosa [UNESP]. "Estruturas vesiculares em misturas de surfactantes catiônicos." Universidade Estadual Paulista (UNESP), 2008. http://hdl.handle.net/11449/100458.
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alves_fr_dr_sjrp.pdf: 2029517 bytes, checksum: f737742cea44bc8699abdd17def3823d (MD5)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Estudos de calorimetria diferencial de varredura (DSC) e fluorescência de estado estacionário da sonda Vermelho do Nilo indicam a formação de vesículas de DODAX (X = Cl- ou Br-) em concentrações de surfactantes tão baixas quanto 10 µM. Estas vesículas foram denominadas microvesículas (µV), cuja Tm diminui monotonicamente com a concentração de DODAX até valores de Tm das vesículas tradicionais preparadas em 1.0 mM do surfactante. O efeito do contra-íon (Br- e Cl-) no comportamento termotrópico de fase das vesículas mistas de DODAB-DODAC foi investigado por DSC, condutimetria e espalhamento dinâmico de luz (DLS). Observou-se que a Tm aumenta sigmoidalmente de 45.8 a 48.9 oC com a fração molar de DODAC (xDODAC), com um ponto de inflexão no ponto eqüimolar. A condutividade e o diâmetro hidrodinâmico das vesículas variam muito pouco com xDODAB, indicando que a densidade superficial de carga das vesículas de DODAX é semelhante entre si, e o efeito do contra íon na Tm de DODAX se deve a interações específicas desses contra-íons na interface das vesículas. Medidas de DSC, fluorescência e turbidez de misturas de DODAB-DDAB indicam que as vesículas de DODAB têm maior afinidade por DDAB do que o oposto, resultando na formação de duas populações de vesículas mistas de DDAB-DODAB, com propriedades distintas. Além disso, medidas de fluorescência mostraram que a presença de pequena quantia de DODAB incorporado nas vesículas de DDAB causa um efeito significante na emissão da sonda devido ao aumento do tamanho das vesículas, sugerido por medidas de turbidez. O estudo dos sistemas DODAB/CnTAB/água na concentração total de surfactante igual a 1,0 e 5,0 mM, variando a concentração de CnTAB, e também mantendo a concentração de DODAB fixa em 1,0 mM, revelou uma forte dependência do comprimento da cadeia de hidrocarbonetos...
Differential scanning calorimetry (DSC) and fluorescence of the probe Nile Red studies reveal the formation of DODAX vesicles (X = Br- and Cl-) at surfactant concentrations as low as 10 µM. These vesicles were referred to as microvesicles (mV), whose Tm decreases monotonically with increasing DODAX concentration to the value for the ordinary vesicles at 1 mM. The effect of counterion (Br- and Cl-) on the thermotropic phase behavior of mixed DODAB-DODAC vesicles were investigated by differential scanning calorimetry (DSC), conductimetry and dynamic light scattering (DLS). Tm increases sigmoidally from 45.8 to 48.9 oC with DODAC molar fraction (xDODAC), with an inflection point at the equimolarity. The conductivity and the apparent hydrodynamic diameter vary little with xDODAB, indicating that the surface charge density is similar for DODAX, evidencing that the effect of counterion on Tm is due to the counterion specific interactions. DSC, fluorescence and turbidity measurements indicate a higher affinity of DDAB for DODAB vesicles than the reverse, resulting in two populations of mixed DDAB-DODAB vesicles with different properties. Besides, fluorescence measurements show that the presence of a small amount of DODAB in DDAB vesicles causes a pronounced effect on the Nile Red emission, due to the increase in vesicle size, as suggested from turbidity results. The study of DODAB/CnTAB/água systems at 1.0 and 5.0 total surfactant concentration, and varying CnTAB concentrations with constant 1.0 mM DODAB revealed a strong dependence of the chain length n and relative concentration of the surfactante in the properties of mixed DODAB-CnTAB vesicles. This study allowed analyzing the thermotropic phase behavior containing different amount of DODAB, and the mechanism of vesicle-micelle transition with increasing CnTAB concentration, below and above CMC... (Complete abstract click electronic access below)
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Reis, Roberta Cristina Novaes dos. "Síntese de surfactantes derivados da D-ribonolactona." Universidade Federal de Juiz de Fora (UFJF), 2007. https://repositorio.ufjf.br/jspui/handle/ufjf/4292.
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CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
Surfactantes são substâncias anfifílicas utilizadas amplamente nas indústrias cosmética, alimentícia, de tintas, etc. A necessidade de produtos obtidos a partir de matéria-prima natural ao invés de derivados do petróleo tem conduzido pesquisadores a desenvolver “surfactantes naturais” derivados de carboidratos, biodegradáveis e atóxicos. No presente trabalho relata-se a preparação de compostos anfifílicos derivados da D-ribonolactona, que podem também atuar como agentes antibacterianos e fungicidas. Descrevemos a síntese e caracterização de diaminas N-alquiladas com cadeias carbônicas de diferentes tamanhos e suas respectivas ribonamidas, além da síntese de hidrazonas derivadas da D-ribonolactona. As diaminas monoalquiladas foram preparadas pela reação de mesilatos ou cloretos de alquila com 1,2-etanodiamina e 1,3-propanodiamina em etanol sob refluxo. As ribonamidas foram obtidas pela condensação destes intermediários aminados com a D-ribonolactona. As hidrazonas foram obtidas pela condensação de aldeídos de cadeia longa com a hidrazida, esta obtida pela reação da D-ribonolactona com hidrazina hidratada 80%. As estruturas dos produtos obtidos foram elucidadas pelos seus espectros no infravermelho, RMN de 1H, RMN de 13C e por análise elementar, além de espectros de massas para alguns compostos. Foram feitas medidas de tensão superficial para determinação da Concentração Micelar Crítica para algumas ribonamidas. Atividade biológica contra Mycobacterium Tuberculosis, Cândida albicans, Staphylococcus aureus e Escherichia coli foi avaliada para as ribonamidas e hidrazonas.
Surfactants are amphiphilic compounds widely used in cosmetics, food and paint industries. The need for products obtained from natural raw materials instead of petroleum derivatives has led searchers, to the development “natural surfactants” derivated from carbohydrates, biodegradable and atoxic. In this work, we describe the preparation of amphiphilic compounds derivated from D-(+)-ribonic γ-lactone, which can also act as antibacterial and antifungal agents. We describe the synthesis and characterization of N-alkyl diamines bearing carbonic chain of several extent, and its respective ribonamides, beyond of the synthesis of hydrazones derivative from D-(+)-ribonic γ-lactone. The monoalkylated diamines were prepared by reaction of the mesylates or alkyl chlorides with 1,2-ethanediamine and 1,3-propanediamine in ethanol under reflux. The ribonamides were obtained by condensation of these aminated intermediates with D(+)ribonic γ-lactone. The hydrazones were obtained by condensation of long chain aldehydes with hydrazide, latter preparated by reation of D-(+)-ribonic γ-lactone with hydrazine hydrate 80%. The structures of the obtained products were elucidated by infrared spectroscopy, 1H and 13C NMR spectroscopy and by elemental analyses, beyond mass spectrometry for any compounds. Surface tension measurements were done for determination of critical micelle concentration of some ribonamides. Biological activity against Mycobacterium tuberculosis, Cândida albicans, Staphylococcus aureus and Escherichia coli was evaluated for ribonamides and hydrazones.
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Alves, Fernanda Rosa. "Estruturas vesiculares em misturas de surfactantes catiônicos /." São José do Rio Preto : [s.n.], 2008. http://hdl.handle.net/11449/100458.
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Orientador: Eloi da Silva FeitosaBanca: Pietro Ciancaglini
Banca: Rosangela Itri
Banca: João Ruggiero Neto
Banca: Vera Aparecida de Oliveira Tiera
Resumo: Estudos de calorimetria diferencial de varredura (DSC) e fluorescência de estado estacionário da sonda Vermelho do Nilo indicam a formação de vesículas de DODAX (X = Cl- ou Br-) em concentrações de surfactantes tão baixas quanto 10 µM. Estas vesículas foram denominadas microvesículas (µV), cuja Tm diminui monotonicamente com a concentração de DODAX até valores de Tm das vesículas tradicionais preparadas em 1.0 mM do surfactante. O efeito do contra-íon (Br- e Cl-) no comportamento termotrópico de fase das vesículas mistas de DODAB-DODAC foi investigado por DSC, condutimetria e espalhamento dinâmico de luz (DLS). Observou-se que a Tm aumenta sigmoidalmente de 45.8 a 48.9 oC com a fração molar de DODAC (xDODAC), com um ponto de inflexão no ponto eqüimolar. A condutividade e o diâmetro hidrodinâmico das vesículas variam muito pouco com xDODAB, indicando que a densidade superficial de carga das vesículas de DODAX é semelhante entre si, e o efeito do contra íon na Tm de DODAX se deve a interações específicas desses contra-íons na interface das vesículas. Medidas de DSC, fluorescência e turbidez de misturas de DODAB-DDAB indicam que as vesículas de DODAB têm maior afinidade por DDAB do que o oposto, resultando na formação de duas populações de vesículas mistas de DDAB-DODAB, com propriedades distintas. Além disso, medidas de fluorescência mostraram que a presença de pequena quantia de DODAB incorporado nas vesículas de DDAB causa um efeito significante na emissão da sonda devido ao aumento do tamanho das vesículas, sugerido por medidas de turbidez. O estudo dos sistemas DODAB/CnTAB/água na concentração total de surfactante igual a 1,0 e 5,0 mM, variando a concentração de CnTAB, e também mantendo a concentração de DODAB fixa em 1,0 mM, revelou uma forte dependência do comprimento da cadeia de hidrocarbonetos... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: Differential scanning calorimetry (DSC) and fluorescence of the probe Nile Red studies reveal the formation of DODAX vesicles (X = Br- and Cl-) at surfactant concentrations as low as 10 µM. These vesicles were referred to as microvesicles (mV), whose Tm decreases monotonically with increasing DODAX concentration to the value for the ordinary vesicles at 1 mM. The effect of counterion (Br- and Cl-) on the thermotropic phase behavior of mixed DODAB-DODAC vesicles were investigated by differential scanning calorimetry (DSC), conductimetry and dynamic light scattering (DLS). Tm increases sigmoidally from 45.8 to 48.9 oC with DODAC molar fraction (xDODAC), with an inflection point at the equimolarity. The conductivity and the apparent hydrodynamic diameter vary little with xDODAB, indicating that the surface charge density is similar for DODAX, evidencing that the effect of counterion on Tm is due to the counterion specific interactions. DSC, fluorescence and turbidity measurements indicate a higher affinity of DDAB for DODAB vesicles than the reverse, resulting in two populations of mixed DDAB-DODAB vesicles with different properties. Besides, fluorescence measurements show that the presence of a small amount of DODAB in DDAB vesicles causes a pronounced effect on the Nile Red emission, due to the increase in vesicle size, as suggested from turbidity results. The study of DODAB/CnTAB/água systems at 1.0 and 5.0 total surfactant concentration, and varying CnTAB concentrations with constant 1.0 mM DODAB revealed a strong dependence of the chain length n and relative concentration of the surfactante in the properties of mixed DODAB-CnTAB vesicles. This study allowed analyzing the thermotropic phase behavior containing different amount of DODAB, and the mechanism of vesicle-micelle transition with increasing CnTAB concentration, below and above CMC... (Complete abstract click electronic access below)
Doutor
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Silva, Douglas Kais da. "Comportamento eletroquímico das interfases cobre-H2SO4 na ausência e presença de triazóis, surfactantes e misturas composto triazólico-surfactante." Universidade de São Paulo, 2006. http://www.teses.usp.br/teses/disponiveis/46/46132/tde-24042007-164032/.
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Foi estudado o comportamento eletroquímico de interfases Cu/H2SO4 0,5 mol L-1 na ausência e presença de compostos triazólicos - benzotriazol (BTAH) e tolitriazol (TTAH) e de surfactantes: dodecilsulfato de sódio (SDS aniônico) e cloreto de dodecilamônio (DAC catiônico) a 25ºC, empregando eletrodo parado e de disco rotativo (EDR). Foram empregadas como técnicas medidas de potencial de circuito aberto, polarização potenciostática e potenciodinâmica, cronoamperometria, espectroscopia de impedância eletroquímica e microscopia óptica. As características inibidoras do filme formado dependem da natureza dos aditivos e das condições hidrodinâmicas. As interfases contendo BTAH, TTAH, BTAH + TTAH, BTAH + SDS e TTAH + SDS apresentaram uma faixa ampla de potencial em que o cobre se mostrou passivado, chegando a 200 mV para a mistura BTAH + SDS empregando EDR. Densidades de corrente de passivação tão baixas quanto 2µA cm-2 foram observadas com EDR na presença de BTAH + TTAH. As misturas composto triazólico - surfactante mostraram filmes menos resistentes. Os surfactantes isolados não produzem faixa passiva e antecipam o potencial de oxidação do cobre com eletrodo parado. As misturas triazol - DAC só produzem faixa passiva com EDR. Todos os aditivos se mostraram inibidores para a reação H+/H2, destacando-se, com eletrodo parado, BTAH, TTAH e BTAH + TTAH.The electrochemical behavior of 0.5 mol.L-1 Cu/H2SO4 interphases has been studied in the presence and in the absence of triazolic compounds-benzotriazole (BTAH) and tolitriazole (TTAH) and of surfactants - sodium dodecylsulphate (anionic, SDS) and dodecylammonium chloride (cationic, DAC) at 25ºC, using non-stirred electrode and rotating disc electrode (RDE). Open circuit potential, potentiostatic and potenctiodinamic polarization, chronoamperometry, electrochemical impedance spectroscopy, and optical microscopy were used as techniques. The inhibitive features of the formed film depend on both the nature of the additives and on the hydrodynamic conditions. The interphases containing BTAH, TTAH, BTAH + TTAH, BTAH + SDS e TTAH + SDS presented a wide potential range where the copper is passivated, reaching to 200 mV for BTAH + SDS mixture using RDE. Low passivating current densities (2µA cm-2) were observed with RDE in the presence of BTAH + TTAH. Triazolic compound?surfactant mixtures have originated less resistant films. Isolated surfactants do not originate passive ranges and anticipate the oxidation potential of copper under non stationary conditions. The mixtures triazole-DAC only produce passive range at stationary conditions. All the additives have shown to be inhibitors for the H+/H2 reaction, specially BTAH, TTAH e BTAH + TTAH using non stirred conditions.
Books on the topic "Surfactantes"
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Rooney, Seamus A. Lung surfactant: Cellular and molecular processing. Austin, TX: Landes Bioscience, 1998.
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1952-, Müller B., Wichert P. von, and International Symposium on Lung Surfactant (4th : 1992 : Marburg, Germany), eds. Lung surfactant: Basic research in the pathogenesis of lung disorders. Basel: Karger, 1994.
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Hayes, Teresa L., Wendy F. Marley, and Kelly Misch. Surfactants. Cleveland, OH: Freedonia Group, 1998.
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Tsujii, Kaoru. Surface activity: Principles, phenomena, and applications. San Diego: Academic Press, 1998.
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Hollis, Gordon L., ed. Surfactants Europa. Cambridge: Royal Society of Chemistry, 2007. http://dx.doi.org/10.1039/9781847551979.
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Saxena, Neha, and Ajay Mandal. Natural Surfactants. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-030-78548-2.
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Sayyed, R. Z., and Hesham All El-Enshasy. Microbial Surfactants. Boca Raton: CRC Press, 2022. http://dx.doi.org/10.1201/9781003247739.
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Sayyed, R. Z. Microbial Surfactants. Boca Raton: CRC Press, 2022. http://dx.doi.org/10.1201/9781003260165.
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Robb, I. D., ed. Specialist Surfactants. Dordrecht: Springer Netherlands, 1996. http://dx.doi.org/10.1007/978-94-009-1557-2.
Full textBook chapters on the topic "Surfactantes"
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Schwarz, G., and E. Vaeth. "Analysis of Surfactants and Surfactant Formulations." In Surfactants in Consumer Products, 440–49. Berlin, Heidelberg: Springer Berlin Heidelberg, 1987. http://dx.doi.org/10.1007/978-3-642-71545-7_7.
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Bhat, G. R., and D. L. Harper. "Measurement of Foaming Properties of Surfactants and Surfactant Products." In Surfactants in Solution, 381–99. Boston, MA: Springer US, 1989. http://dx.doi.org/10.1007/978-1-4615-7990-8_28.
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Florence, A. T., and D. Attwood. "Surfactants." In Physicochemical Principles of Pharmacy, 173–227. London: Macmillan Education UK, 1988. http://dx.doi.org/10.1007/978-1-349-16558-2_6.
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Bährle-Rapp, Marina. "Surfactants." In Springer Lexikon Kosmetik und Körperpflege, 539. Berlin, Heidelberg: Springer Berlin Heidelberg, 2007. http://dx.doi.org/10.1007/978-3-540-71095-0_10238.
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Bisht, Anu Singh. "Surfactants." In Commercial Surfactants for Remediation, 17–23. Singapore: Springer Singapore, 2018. http://dx.doi.org/10.1007/978-981-13-0221-3_4.
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Tadros, Tharwat. "Surfactants." In Encyclopedia of Colloid and Interface Science, 1242–90. Berlin, Heidelberg: Springer Berlin Heidelberg, 2013. http://dx.doi.org/10.1007/978-3-642-20665-8_40.
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Gbadamosi, Afeez, Adeyinka Yusuff, Augustine Agi, and Jeffrey Oseh. "An Overview of Natural Surfactant Application for Enhanced Oil Recovery." In Enhanced Oil Recovery: Selected Topics [Working Title]. IntechOpen, 2022. http://dx.doi.org/10.5772/intechopen.104935.
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Surfactant flooding is an enhanced oil recovery (EOR) method that recovers residual and capillary trapped oil by improving pore scale displacement efficiency. Due to toxicity and high cost of conventional surfactant, recent trend involves the use of natural surfactant for EOR. Natural surfactants are benign and biodegradable as they are derived from plant leaves and oil extracts. Herein, a synopsis of recent trend in the incorporation of newly devised natural surfactant for EOR was reviewed. Experimental results show that the surfactants exhibited sterling properties desired for EOR such as lower adsorption, interfacial tension (IFT) reduction, stable emulsion, and wettability alteration of sandstone and carbonate rocks. Overall, natural surfactants are suitable replacement for conventional surfactant. Nonetheless, an accurate modeling and pilot scale studies of natural surfactants remain obscure in literature.
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Medeiros, Anderson Oliveira de, Maria da Gloria Conceição da Silva, and Leonie Asfora Sarubbo. "FORMULAÇÃO DE MATRIZES ANTI-INCRUSTANTES UTILIZANDO SURFACTANTES NATURAIS." In Desenvolvimento e Transferência de Tecnologia na Engenharia Química, 87–99. Atena Editora, 2020. http://dx.doi.org/10.22533/at.ed.0652009128.
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Banjare, Bhupendra Singh, and Manoj Kumar Banjare. "SURFACTANTS CHALLENGES, METHODOLOGY AND ITS VERSATILE APPLICATION." In Futuristic Trends in Chemical Material Sciences & Nano Technology Volume 3 Book 6, 125–54. Iterative International Publishers, Selfypage Developers Pvt Ltd, 2024. http://dx.doi.org/10.58532/v3bjcs6p2ch3.
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Modern science demands sustainable, effective, and natural chemicals that make human life easy and harmless, surfactant is one of them. Surfactants are the most widely used chemicals in industry such as clothing, foods, detergents, pharmaceuticals, and agriculture to modern science. Surfactant is a surface-active agent consisting of organic compounds of amphipathic character with great structural diversity. Surfactants' capacity to self-assemble is a highly potent function for many systems that influences the solubility of the weakly water-soluble products to boost their availability. The commercialization of surfactants has been going on for centuries. The effective surfactant can be detected by its physicochemical behavior. Various physicochemical properties of surfactants are determined through different techniques i.e., DLS, UV-visible spectroscopy, surface tension, conductometry, viscometry etc. The mix-micellar activity of two different types of surfactants is known by a variety of theoretical models such as Clint's, Rubing's, etc. Surfactants have a diverse variety of uses, which increases the need for future research that is more sophisticated.This review provides a detailed, well-articulated overview of surfactant classification, characteristics, applications, challenges, future aspects in various fields, and different techniques.
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Dorai, Sandya Tambi, Priya Tiwari, Yashi Dwivedi, and Sandeep Chandrashekharappa. "Surfactant Sensors for Food Quality Monitoring." In Surfactant-based Sensors in Chemical and Biochemical Detection, 149–62. Royal Society of Chemistry, 2023. http://dx.doi.org/10.1039/bk9781837671182-00149.
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This chapter explores the market’s existing surfactant food sensors and their specificity for identifying food constituents of high quality. Surfactants are compounds that are widely used in food production and processing as they play an important role in modifying the surface properties of food materials. They provide a fast, accurate, and reliable means of detecting surfactants in food samples. The detection of surfactants in food is critical to ensure that the food meets regulatory standards and is safe for consumption. In recent years, significant progress has been made in the development of surfactant sensors for food quality monitoring. Researchers have explored various materials such as graphene, nanoparticles, and polymers to develop highly sensitive and selective sensors. Moreover, the use of machine learning and artificial intelligence has enhanced the accuracy and reliability of surfactant sensors. Surfactant sensors have become a vital tool in food quality monitoring. They have the potential to significantly improve food safety and quality by detecting the presence of harmful surfactants in food samples. Future research should focus on improving the sensitivity and selectivity of surfactant sensors, developing cost-effective and portable devices, and exploring their potential applications in various food products.
Conference papers on the topic "Surfactantes"
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Diaz Ramirez, Mayra, and Felipe García Ochoa. "Bio Surfactantes producidos por enterobacterias." In Conferencia Interdisciplinaria de Avances en Investigación. Lerma Estado de México, México: Universidad Autónoma Metropilitana, Unidad Lerma, 2018. http://dx.doi.org/10.24275/uam/lerma/repinst/ciai2018/000145/diaz.
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Rocha, Bianca Floriano da, and João Victor Nicolini. "Aplicação de surfactantes naturais na Recuperação Avançada do Petróleo." In Anais do I Web Encontro Nacional de Engenharia Química. Recife, Brasil: Even3, 2021. http://dx.doi.org/10.29327/138535.1-86.
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Sobrinho, Leonardo Zborowski, and Cesar Liberato Petzhold. "SÍNTESE DE SURFACTANTES “GEMINI” CATIÔNICOS A PARTIR DE AMIDAS GRAXAS." In V Congresso Online Nacional de Química. Congresse.me, 2023. http://dx.doi.org/10.54265/hmih6712.
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MELGAR, LISBETH ZELAYARAN, LISBETH ZELAYARAN MELGAR, GUSTAVO DE OLIVEIRA WERNECK, JORGE DAVID ALGUIAR BELLIDO, and ELIANE PRADO CUNHA COSTA DOS SANTOS. "ADSORçãO DE DICLOFENACO EM BENTONITA MODIFICADO COM SURFACTANTES: ESTUDO CINéTICO." In XIII Congresso Brasileiro de Engenharia Química em Iniciação Científica. São Paulo: Editora Blucher, 2019. http://dx.doi.org/10.5151/cobecic2019-eat134.
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Gbonhinbor, Jeffrey, Ann Obuebite, George Kuradoite, and Augustine Agi. "Characteristic Curvature Assessment of Some Natural Surfactants for Chemical Enhanced Oil Recovery Applications in Nigeria." In SPE Nigeria Annual International Conference and Exhibition. SPE, 2022. http://dx.doi.org/10.2118/211996-ms.
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Abstract Chemical enhanced oil recovery (CEOR) application of natural surfactants is based on potential interfacial tension (IFT) alterability and eco-friendly considerations. The reduced IFT is associated with microemulsion formation in relation to a surfactant’s characteristic curvature. Lately, surface activities of natural surfactants have gained interest in Nigerian laboratory studies with no attention given to their hydrophilicity/hydrophobicity. This research focuses on molecular weight determination, micelle formation, and characteristic curvature evaluation of readily available natural surfactants. Four plants that are known to possess relevant surfactant properties were selected for this evaluation. Freezing point dipping method was used to determine the average molecular weight of each surfactant. Critical micelle concentration (CMC) was ascertained by electric conductivity tests. Characteristic curvature was evaluated from microemulsion formulations of toluene and aqueous surfactant mixtures. Formulated aqueous surfactant mixture consists of a combination of selected natural surfactant and a reference surfactant. Sodium dodecylsulphate (SDS) was adopted as the reference surfactant throughout this work. The analysis was configured in line with the hydrophilic-lipophilic deviation (HLD) model set to 0. Results yielded average molecular weights of examined surfactants between 128.3 g/mol to 186.7 g/mol. Critical micelle concentrations values of 0.45 to 0.60 were derived for all natural surfactants. Estimated characteristic curvature values suggested hydrophobicity with values from 0.116 to 0.194. As a consequence, these natural surfactants possess a tendency to form reverse micelles due oleic phase attraction. Their low positive values make them suitable for lowering IFT in order to mobilise trapped formation oil.
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OLIVEIRA, L. B., L. L. SILVA, A. F. P. CAMPOS, and D. CARDOSO. "PROPRIEDADES DE DISPERSÕES DE SURFACTANTES PARA A SÍNTESE DE SÍLICAS HÍBRIDAS." In Congresso Brasileiro de Engenharia Química em Iniciação Científica. São Paulo: Editora Blucher, 2017. http://dx.doi.org/10.5151/chemeng-cobeqic2017-160.
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Pereira, A. C., J. R. S. Barreto, A. M. Oliveira Júnior, and J. J. S. Moreira. "INVESTIGAÇÃO DAS PROPRIEDADES SURFACTANTES DE EXTRATO FRACIONADO DE RESÍDUO DE GRAVIOLA." In 6th International Symposium on Technological Innovation. Universidade Federal do Sergipe, 2015. http://dx.doi.org/10.7198/s2318-3403201500030013.
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ASSIS, R. M., A. C. P. GUIMARÃES, and G. L. V. COELHO. "SÍNTESE E DETERMINAÇÃO DE PARÂMETROS DE SUPERFÍCIE E TERMODINÂMICOS DE SURFACTANTES CATIÔNICOS." In Congresso Brasileiro de Engenharia Química em Iniciação Científica. São Paulo: Editora Blucher, 2017. http://dx.doi.org/10.5151/chemeng-cobeqic2017-201.
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BERALDO, C. S., R. C. SANTANA, and Y. N. NARIYOSHI. "AVALIAÇÃO EXPERIMENTAL DO USO DE SURFACTANTES NA DESESTABILIZAÇÃO DE EMULSÕES DE PETRÓLEO." In XXII Congresso Brasileiro de Engenharia Química. São Paulo: Editora Blucher, 2018. http://dx.doi.org/10.5151/cobeq2018-pt.0687.
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Barros, Márcio de, Maria Inês Rezende, Milena Martins Andrade, and Aneli M. Barbosa. "Efeitos de surfactantes na atividade catalítica da lipase de Botryosphaeria ribis EC-01." In V Simpósio de Bioquímica e Biotecnologia. São Paulo: Editora Edgard Blücher, 2015. http://dx.doi.org/10.5151/biochem-vsimbbtec-21943.
Full textReports on the topic "Surfactantes"
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Weiss and Xie. WVJB8LP Smart Gas - Using Chemicals to Improve Gas Deliverability. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), January 2008. http://dx.doi.org/10.55274/r0010902.
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Each year, more than 17,000 gas storage wells in the United States lose from 3�5% of their storage capacity and deliverability. In addition, the gas storage industry spends $80�100 million annually to revitalize existing wells; thus, there is an economic incentive to develop new stimulation methods. Limited laboratory information suggests that using surfactants to alter the wettability of the reservoir rock could increase deliverability of gas storage wells. The objective of this project was to develop new technology to improve deliverability from gas storage wells. Two cost-effective surfactants were selected from 11 candidates through preliminary screening tests for additional reservoir core tests. Reservoir cores from three gas storage facilities including sandstone and dolomite reservoirs were used to evaluate surfactant-gas-core systems. The imbibition and core flood tests showed that gas deliverability and storage capacity were improved in surfactant-treated sandstone cores. However, the surfactants had a very limited effect on dolomite cores. An engineering analysis was conducted to develop an analytical method to evaluate future field tests of the new technology. The aquifer storage facilities are candidates for field testing.
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Weiss. PR-318-08700-R01 Smart Gas-Using Chemicals to Improve Gas Deliverability-Phase II. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), March 2009. http://dx.doi.org/10.55274/r0010944.
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In water-wet gas storage reservoirs, the imbibition force promotes the retention of water in the pore space, which curtails the deliverability of gas to the wellbore during periods of high demand. Similarly, the injection of gas during the fill cycle is restricted. In addition, the pore space occupied by irreducible water is not available to hold gas. The objective of this Phase II project was to demonstrate in the field the new technology developed in the laboratory during Phase I. Wettability alteration was evaluated as a technique to improve gas deliverability from gas storage wells during Phase I. During the first year, two cost-effective surfactants were selected from 11 candidates through various laboratory screening and reservoir core tests. Reservoir cores from three gas storage facilities including sandstone and dolomite reservoirs were used to evaluate the two surfactants. The imbibition and core flood tests showed that gas deliverability and storage capacity were improved in surfactant-treated sandstone cores. However, these surfactants had a very limited effect on dolomite cores. An engineering analysis was conducted to develop an analytical method for evaluating future field tests of the new technology. It was concluded that the aquifer storage facilities are candidates for field testing. Results from Phase I provided the foundation for this Phase II project.
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Weiss. L52296 Smart Gas Using Chemicals To Improve Gas Deliverability Phase II. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), March 2009. http://dx.doi.org/10.55274/r0010658.
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The objective of this effort was to demonstrate in the field the new wettability altering technology developed in the laboratory during Phase 1. Reservoir cores from three gas storage facilities including sandstone and dolomite reservoirs were used to evaluate the two surfactants. The imbibition and core flood tests showed that gas deliverability was improved in surfactant-treated sandstone cores. It was concluded that the aquifer storage facilities are candidates for field testing. Results from Phase I provided the foundation for this Phase II project. The Waverly Storage Facility operated by Southern Union/Panhandle Energy was selected as the site for a field test of the surfactant process. Waverly is an 1800-ft sandstone aquifer gas storage reservoir located near Springfield, lllinois. Expansion and contraction of a spherical gas bubble provided pressure support as gas was injected and withdrawn from 37 individual wells. Three wells were selected for treatment with 1000 bbl of ~4% surfactant solution. An additional three nearby wells were selected as control wells. A field mixing procedure similar to that used in the laboratory to avoid phase separation of the microemulsion was developed and successfully used during the third week of October 2007 when the wells were treated. Rates and pressures were measured at the wellhead; fluid levels were not recorded. Since the initial rate-pressure data collected during the project year including the well treatments were sparse, it was decided to extend the project to the end of 2008 to acquire more field data.
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Lebone T. Moeti and Ramanathan Sampath. Characterization of Phase and Emulsion Behavior, Surfactant Retention, and Oil Recovery for Novel Alcohol Ethoxycarboxylate Surfactants. Office of Scientific and Technical Information (OSTI), May 1998. http://dx.doi.org/10.2172/1623.
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Lebone T. Moeti and Ramanathan Sampath. CHARACTERIZATION OF PHASE AND EMULSION BEHAVIOR, SURFACTANT RETENTION, AND OIL RECOVERY FOR NOVEL ALCOHOL ETHOXYCARBOXYLATE SURFACTANTS. Office of Scientific and Technical Information (OSTI), September 2001. http://dx.doi.org/10.2172/833446.
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LEBONE MOETI and RAMANATHAN SAMPATH. CHARACTERIZATION OF PHASE AND EMULSION BEHAVIOR, SURFACTANT RETENTION, AND OIL RECOVERY FOR NOVEL ALCOHOL ETHOXYCARBOXYLATE SURFACTANTS. Office of Scientific and Technical Information (OSTI), November 1998. http://dx.doi.org/10.2172/7479.
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Viers, Brent D., Alan Esker, and Katie Farmer. Polyhedral Oligomeric Silsesquioxanes Surfactants. Fort Belvoir, VA: Defense Technical Information Center, January 2001. http://dx.doi.org/10.21236/ada410399.
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Morgan, Matthew Earle. Solubilization of pentanol by cationic surfactants and binary mixtures of cationic surfactants. Office of Scientific and Technical Information (OSTI), January 1993. http://dx.doi.org/10.2172/10146350.
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Walker, David, and Jeffrey Renfrow. Toxicological reconnaissance of Arsenal? use along the Rio Grande River through Big Bend National Park: Final report. National Park Service, 2024. http://dx.doi.org/10.36967/2302769.
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This study examined the biological response of aquatic organisms, collected in situ and from laboratory toxicity testing of water and soil to the herbicide Arsenal? primarily used to decrease the invasive species Arundo donax in the Rio Grande River through Big Bend National Park in Texas (USA). Biological, toxicological, physicochemical, and flow data were collected before, during, and after an Arsenal? treatment from 4 reference and 3 treatment sites. Significant differences existed in ecoregion 24 B-IBI scoring, and in toxicity testing of water and sediment, between treatment and reference sites. Greater toxicity, and a higher inverse relationship to B-IBI scoring, was observed in sediment samples compared to water samples. This could be due to the surfactant nonylphenol ethoxylate (NPE), added to the Arsenal? formulation rather than the active ingredient imazapyr. Care must be implemented with the results of this research due to many confounding variables that occurred during the study period including flash flooding. Although flashy hydrology is relatively common to the region, it can influence aquatic macroinvertebrate assemblage structure, function, and species richness measures with these dropping due to scour and downstream displacement within a reach during, and for some period following, flooding. Therefore, flash flooding would be expected to have some effect on aquatic macroinvertebrate assemblages and subsequent B-IBI scoring. Additionally, flooding will cause some displacement, and deposition, of sediment throughout the study area. This flooding could impact the sediment toxicity results as sediment-bound contaminants could be spread some distance from their origin. Arsenal? treatment occurred during this study near sites Treatment 1 and Treatment 2 on 5/29 and 5/31 2022 respectively. This represented an extreme condition as far as concentration of potential toxicants in the water are concerned and these relatively high concentrations would be expected to have decreased within a relatively short period of time, especially in the water. It was outside of the scope and budget of this project to obtain concentrations of imazapyr or surfactants from sediment or water. Therefore, exact doses of imazapyr or surfactant for response curves could not be obtained. No sample site exists in isolation rather, influences from one reach can significantly impact downstream areas. This is especially true for aquatic ecosystems in arid regions that often exhibit flashy hydrology. However, we believe the findings from this study provide indication of potential toxicity of some magnitude as well as provide direction for management. Decisions of whether the toxic effects of herbicide use to aquatic macroinvertebrates outweigh the beneficial effects of Arundo donax control should be carefully considered.
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Vane, Leland, A. L. Wood, Gary A. Pope, and Edwin E. Tucker. Surfactant Enhanced DNAPL Removal. Fort Belvoir, VA: Defense Technical Information Center, August 2001. http://dx.doi.org/10.21236/ada607317.
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