The effect of organic acids and salinity on the interfacial tension of n-decane/ water systems

Amr M. Sayed, Kristian B. Olesen, Abdul Sattar Alkahala, Theis I. Sølling, Nayef Al Yafei

Research output: Contribution to journalArticle

Abstract

We have investigated how a homologous series of straight-chain carboxylic acids with a cyclohexyl substituent in the opposite end of the functional groups impacts the interfacial tension (IFT) between decane (oil) and water. The employed method was the pendant droplet technique. We do not observe any striking effect of expanding the chain length: all acids reduced the IFT compared to water by approximately 20 mN/m. Additionally, the effect of changing the chemical character and the concentration of the cation in a series of brines where studied too, and again we do not observe a significant IFT impact. The only modification that significantly reduces the IFT is the modification of the anion from chloride to carbonate, a change that results in an increased pH and thus a transformation of the constituent acids from their neutral to their anionic form. This is expected to result in a reduced IFT because of the polar end of the surfactant is even more polar which alleviates the stress on the surface.

LanguageEnglish
Pages1047-1052
Number of pages6
JournalJournal of Petroleum Science and Engineering
Volume173
DOIs
Publication statusPublished - 1 Feb 2019

Fingerprint

Organic acids
organic acid
Surface tension
salinity
Water
water
Brines
Acids
acid
carboxylic acid
Carboxylic acids
Chain length
Functional groups
functional group
droplet
surfactant
anion
Carbonates
Surface active agents
Negative ions

Keywords

  • Carboxylic acids
  • IFT
  • Pendant droplet
  • Salinity
  • Surfactants

ASJC Scopus subject areas

  • Fuel Technology
  • Geotechnical Engineering and Engineering Geology

Cite this

The effect of organic acids and salinity on the interfacial tension of n-decane/ water systems. / Sayed, Amr M.; Olesen, Kristian B.; Alkahala, Abdul Sattar; Sølling, Theis I.; Al Yafei, Nayef.

In: Journal of Petroleum Science and Engineering, Vol. 173, 01.02.2019, p. 1047-1052.

Research output: Contribution to journalArticle

Sayed, Amr M. ; Olesen, Kristian B. ; Alkahala, Abdul Sattar ; Sølling, Theis I. ; Al Yafei, Nayef. / The effect of organic acids and salinity on the interfacial tension of n-decane/ water systems. In: Journal of Petroleum Science and Engineering. 2019 ; Vol. 173. pp. 1047-1052.
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