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Previous issue date: 2011-08-12 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Alkyl polyethoxylates are surfactants widely used in vastly different fields, from oil
exploitation to pharmaceutical applications. One of the most interesting characteristics of
these surfactants is their ability to form micellar systems with specific geometry, the so-called
wormlike micelle. In this work, microemulsions with three distinct compositions (C/T = 40
%, 30 % and 25 %) was used with contain UNITOL / butanol / water / xylene, cosurfactant /
surfactante (C/S) ratio equal to 0,5. The microemulsion was characterized by dynamic light
scattering (DLS), capillary viscometry, torque rheometry and surface tensiometry experiments
carried out with systems based on xylene, water, butanol (cosurfactant) and nonaethyleneglycolmonododecyl
ether (surfactant), with fixed surfactant:cosurfactant:oil
composition (with and without oil phase) and varying the overall concentration of the
microemulsion. The results showed that a transition from wormlike micelles to nanodrops
was characterized by maximum relative viscosity (depending on how relative viscosity was
defined), which was connected to maximum effective diameter, determined by DLS. Surface
tension suggested that adsorption at the air water interface had a Langmuir character and that
the limiting value of the surfactant surface excess was independent of the presence of
cosurfactant and xylene. The results of the solubilization of oil sludge and oil recovery with
the microemulsion: C/S = 40%, 30% and 25% proved to be quite effective in solubilization of
oil sludge, with the percentage of solubilization (%solubilization) as high as 92.37% and
enhanced oil recovery rates up to 90.22% for the point with the highest concentration of
active material (surfactant), that is, 40%. / Os tensoativos alquil-polietoxilados s?o amplamente utilizados em diferentes campos,
desde a explota??o de petr?leo at? aplica??es na ind?stria farmac?utica. Uma das
caracter?sticas mais interessantes destes tensoativos ? a sua capacidade de formar sistemas
micelares que apresentam uma geometria micelar espec?fica, a chamada micela wormlike,
tipo verme . Neste trabalho, foram utilizados tr?s pontos de microemuls?o: C/T = 40 %, C/T
= 30 % e C/T = 25 % num sistema contendo UNITOL/xileno/butanol/?gua. Esses pontos de
microemuls?o foram caracterizados por espalhamento de luz din?mico (DLS), viscosimetria
capilar, reometria de torque e tens?o superficial com composi??es de tensoativo, cotensoativo
e ?leo fixo - 5 % (com e sem fase ?leo) e variando a concentra??o total dos pontos de
microemuls?o. Os resultados mostraram que a transi??o da geometria de micela wormlike
para nanogotas poderia ser caracterizada por um m?ximo na viscosidade relativa (dependendo
de como a viscosidade foi definida), que foi vinculado a um m?ximo de di?metro efetivo,
determinada por DLS. A tens?o superficial sugeriu que a adsor??o na interface ?gua/ar tinha
um car?ter de Langmuir, o limite de excesso da superf?cie do tensoativo ? independente da
presen?a de cotensoativo e do xileno, e que o valor limite do excesso superficial foi
independente da presen?a de cotensoativo e xileno. Os resultados da solubiliza??o da borra de
petr?leo e da recupera??o avan?ada de petr?leo com os pontos de microemuls?o C/T = 40 %,
C/T = 30 % e C/T = 25 %, se mostraram bastante eficaz com solubiliza??o da borra de
petr?leo, com porcentagem de solubiliza??o (% solubiliza??o) at? 92,37 %, e recupera??o
avan?ada de petr?leo de at? 90,22 % para o ponto que apresenta maior concentra??o de
mat?ria ativa (tensoativo), ou seja, C/T = 40 %.
| Identifer | oai:union.ndltd.org:IBICT/oai:repositorio.ufrn.br:123456789/17743 |
| Date | 12 August 2011 |
| Creators | Silva, Guymmann Clay da |
| Contributors | CPF:90623207753, http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4788562T6, Dantas Neto, Afonso Avelino, CPF:05641284491, http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4783215D9, Wanderley Neto, Alcides de Oliveira, CPF:00738841463, http://lattes.cnpq.br/4789528535524269, Gurgel, Alexandre, CPF:59721421472, http://lattes.cnpq.br/5266735277153768, Leite, Ricardo Henrique de Lima, CPF:52264343400, http://lattes.cnpq.br/3801476460958779, Dantas, Tereza Neuma de Castro, Fonseca, Jos? Luis Cardozo |
| Publisher | Universidade Federal do Rio Grande do Norte, Programa de P?s-Gradua??o em Qu?mica, UFRN, BR, F?sico-Qu?mica; Qu?mica |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/doctoralThesis |
| Format | application/pdf |
| Source | reponame:Repositório Institucional da UFRN, instname:Universidade Federal do Rio Grande do Norte, instacron:UFRN |
| Rights | info:eu-repo/semantics/openAccess |
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