Caracterización interfacial de emulsiones agua-aceite (w/o) estabilizadas por asfáltenos usando espectrometría de masas
En este estudio se preparó una emulsión W/O con agua desionizada y una solución de asfaltenos purificados como moléculas surfactantes. El análisis de estabilidad de la emulsión W/O reveló procesos de sedimentación, variación del tamaño de las gotas de agua dispersas y fenómenos de floculación pero n...
- Autores:
-
Alarcon Hernandez, Elizabeth
- Tipo de recurso:
- http://purl.org/coar/version/c_b1a7d7d4d402bcce
- Fecha de publicación:
- 2016
- Institución:
- Universidad Industrial de Santander
- Repositorio:
- Repositorio UIS
- Idioma:
- spa
- OAI Identifier:
- oai:noesis.uis.edu.co:20.500.14071/34950
- Palabra clave:
- Emulsiones
Espectrometría
Interfacial
Metodologías
In this study
we prepared a W/O emulsion using a fraction of asphaltenes as emulsifiers to stabilize emulsions principal stabilizing surfactant molecules. Although the emulsion stability analysis reveals sedimentation
size variation of the water droplets and flocculation processes
the emulsion was highly stable for days as no free water was observed. The interfacial material was isolated from a W/O emulsion using two approaches previously reported. The first one
involves an extraction of the molecules weakly bound to the interface using toluene 28 and the second
uses heavy water36 as the dispersed phase to separate the most polar molecules by density differences. Infrared spectra
obtained for both interfaces
show characteristic bands associated with oxygenated and aromatic compounds. High resolution mass spectrometry shows the presence of abundant aromatic
sulfur and nitrogen compounds
detected as protonated and radical cations. For the most relative abundant heteroatom classes
we calculated planar limits that ranges between 0
7 and 0
8 for both interfaces suggesting a possible linear addition of polycyclic aromatic rings like in a structural peri-condensation chemical structure. Finally
thermogravimetric analysis (TGA) revealed that isolated interfaces exhibited less thermal stability than the whole asphaltenes
due to the presence of more volatile compounds and degradation of molecules with nitrogen
sulfur and oxygen above 400°C. On the other hand
low molecular weight naphthenic acids can act as demulsifiers
displacing the aromatic asphaltenes molecules found on the interface and destabilizing the W/O emulsion.
- Rights
- License
- Attribution-NonCommercial 4.0 International (CC BY-NC 4.0)