Monitoring the formation kinetics of a bicontinuous microemulsion

Delphine Herrera; Thibaud Chevalier; Didier Frot; Loïc Barré; Audrey Drelich; Isabelle Pezron; Christine Dalmazzone

doi:10.1016/j.jcis.2021.12.011

Monitoring the formation kinetics of a bicontinuous microemulsion

J Colloid Interface Sci. 2022 Mar:609:200-211. doi: 10.1016/j.jcis.2021.12.011. Epub 2021 Dec 3.

Authors

Delphine Herrera¹, Thibaud Chevalier¹, Didier Frot¹, Loïc Barré¹, Audrey Drelich², Isabelle Pezron², Christine Dalmazzone³

Affiliations

¹ IFP Energies nouvelles, 1 et 4 avenue de Bois-Préau, Rueil-Malmaison Cedex 92852, France.
² Université de technologie de Compiègne, ESCOM, TIMR (Integrated Transformations of Renewable Matter), Centre de recherche Royallieu-CS60319, Compiègne Cedex 60203, France.
³ IFP Energies nouvelles, 1 et 4 avenue de Bois-Préau, Rueil-Malmaison Cedex 92852, France. Electronic address: christine.dalmazzone@ifpen.fr.

PMID: 34896824
DOI: 10.1016/j.jcis.2021.12.011

Abstract

Hypotheses: The performance of bicontinuous microemulsions is usually assessed on the characteristics of the middle phase at equilibrium. However, applied to Enhanced Oil Recovery, such an evaluation would not be representative of the structure and composition of fluids in reservoir rocks. Studies on the properties of non-equilibrated microemulsions are still needed to better understand the formation of such complex systems, in particular to optimize input parameters of process simulation tools.

Experiments: For this purpose, we monitored the formation of a microemulsion from contact with the oil to equilibrium when no mixing or convection is provided. Non-destructive methods such as Nuclear Magnetic Resonance, Micro-Computed Tomography, Dynamic Light Scattering and Small Angle X-ray scattering were used to extract the compositions, phase thicknesses, dynamics and structures of the system over time.

Finding: We found that the system gets structured into several layers over time that include the transient presence of an oriented semi-crystalline phase. The growth of the bicontinuous middle phase results from a progressive reorganization of the liquid crystal. The compositional and structural gradients, observed along the sample height, are correlated and linked to the corresponding structures of the phase diagram of the quaternary system. Equilibrium is reached after the total transfer of the liquid crystal into the bicontinuous phase.

Keywords: Bicontinuous; DLS; Formation; Micro-CT; Microemulsions; NMR; Quantification; SAXS; Structure.