Deciphering Zn(II)-Carboxylic Acid Interactions : Tailoring Oil/Water Interfaces and Surfactant Efficiency

This study elucidates the synergistic interactions between dodecanoic acid (C12) and zinc ions (Zn2+) at oil/water interfaces, a critical phenomenon for understanding the intricate dynamics of surfactant systems. Interfacial tension (IFT) measurements, performed via pendant drop tensiometry, reveal...

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Veröffentlicht in:Langmuir : the ACS journal of surfaces and colloids. - 1985. - (2025) vom: 27. Mai
1. Verfasser: Al-Sakkaf, Mohammed K (VerfasserIn)
Weitere Verfasser: Emon Ali, A H M, Baldelli, Steven, Binabdi, Ali, Andersson, Martin P, Sølling, Theis I, El Zohry, Ahmed M
Format: Online-Aufsatz
Sprache:English
Veröffentlicht: 2025
Zugriff auf das übergeordnete Werk:Langmuir : the ACS journal of surfaces and colloids
Schlagworte:Journal Article
Beschreibung
Zusammenfassung:This study elucidates the synergistic interactions between dodecanoic acid (C12) and zinc ions (Zn2+) at oil/water interfaces, a critical phenomenon for understanding the intricate dynamics of surfactant systems. Interfacial tension (IFT) measurements, performed via pendant drop tensiometry, reveal that the pronounced affinity of C12 for the oil/water interface causes an approximate 35% reduction in the IFT (from 50 to about 32 mN/m). However, introducing Zn2+ ions with C12 created an IFT decrease to approximately 22 mN/m, representing an overall reduction of nearly 55%, indicative of their interactions that substantially enhance interfacial adsorption and promote molecular ordering. The stoichiometric relationship between C12 and Zn2+ exhibits a marked concentration dependency. This phenomenon underscores the complex nature of the involved interfacial assembly and the dual role of both C12 and Zn2+ in modulating the physicochemical properties of the interface, which has been supported by the complementary density functional theory (DFT) and COSMO-RS calculations. Moreover, vibrational sum frequency generation (VSFG) spectroscopy corroborates the experimental findings by detecting high-order alkane chain arrangements induced by the Zn2+ ions. These integrated methodologies demonstrate that the Zn2+ ion's role varies, depending on the surface coverage by C12, and causes a more ordered interfacial film under controlled conditions, optimizing the reduction of IFT. Our research introduces a promising approach for creating advanced surfactant systems, emphasizing the intricate role of metal cations like Zn2+ at interfaces in various chemical engineering and environmental management applications.applications
Beschreibung:Date Revised 27.05.2025
published: Print-Electronic
Citation Status Publisher
ISSN:1520-5827
DOI:10.1021/acs.langmuir.5c01055