Development of Composite Materials Based on the Interaction between Nanoparticles and Surfactants for Application in Chemical Enhanced Oil Recovery

The main objective of this work is to develop a nanofluid based on the adsorption/desorption process of cationic, anionic, and nonionic surfactants onto nanoparticles and its application in enhancing the process of oil recovery. The development of the nanofluids was divided into two experimental routes for understanding the adsorption phenomena of the surfactants (cetyltrimethylammonium bromide (CTAB), sodium dodecyl sulfate (SDS), and polyoxyethylenesorbitan monolaurate (Tween 20)) onto silica nanoparticles (SiO₂) by (I) simultaneous addition of nanoparticles and surfactant before micelle formation and (II) the addition of nanoparticles after micelle formation. The adsorption/desorption isotherms for determining the ability of nanoparticles to adsorb surfactants were obtained at 25, 50, and 70 °C using batch-mode experiments. The experimental adsorption isotherms were types I and III depending on the route and the chemical nature of the surfactant and were adequately described by the solid–liquid equilibrium (SLE) model. The amount adsorbed of surfactant onto nanoparticles decreased in the order CTAB > Tween 20 > SDS and was higher for route II than for route I. Meanwhile, the desorption percentages obtained were 2.0, 5.3, and 9.1% for CTAB, Tween 20, and SDS, respectively. The thermodynamic behavior of surfactant adsorption onto SiO₂ nanoparticles suggested that the adsorption was a spontaneous and an exothermic process. From the adsorption/desorption isotherms, a composite nanomaterial for enhancing oil recovery was obtained and was evaluated through interfacial tension (IFT) measurements and displacement tests using a micromodel. The composite material based on nanoparticles–surfactant did not generate a significant effect on interfacial tension compared to the surfactant solution. However, the nanofluid increased the oil recovery up to 240% regarding surfactant flooding.