Liquid Crystal Observations in Emulsion Fractions from Brazilian Crude Oils by Polarized Light Microscopy
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- 作者：Angela C. P. Duncke ; Thiago O. Marinho ; Carla N. Barbato ; Gizele B. Freitas ; Márcia C. K. de Oliveira ; Márcio Nele
- 刊名：Energy & Fuels
- 出版年：2016
- 出版时间：May 19, 2016
- 年：2016
- 卷：30
- 期：5
- 页码：3815-3820
- 全文大小：432K
- 年卷期：0
- ISSN：1520-5029
文摘
The observation of lamellar liquid crystals (LCs) is reported in fractions of Brazilian crude oil emulsions. Through polarized light microscopy, several structures exhibiting Maltese cross-optical pattern were observed, mostly in aqueous-rich fractions (bottom fractions). Microscopy observations were carried out immediately after emulsion preparation and after a destabilization protocol by centrifugation. Four oils were used: two waxy crude oils and two non-paraffinic oils. The experimental variables investigated were oil composition, aqueous content, and saline solution concentration. The liquid crystalline structures had a similar pattern for all samples observed with a thickness of 1.77 ± 0.14 μm surrounding droplets of 4.57 ± 0.47 μm diameter. Neither the presence of wax nor NaCl (up to 35 g/L) exhibited any correlation with liquid crystal (LC) appearance. However, the increase of the aqueous phase added to the systems favoring LC formation.