Influences of hydrophilic and hydrophobic silica nanoparticles on anionic surfactant properties: Interfacial and adsorption behaviors

•Surfactant nanoparticle mixtures were studied for enhancing oil recovery purpose.•Interfacial and adsorption behaviors were thoroughly evaluated.•Stable nanoparticle suspensions were obtained adding low amounts of surfactant.•Nanoparticle inclusion into surfactant solution caused strange interfacial behavior.•Surfactant adsorption on the rock surface was reduced by nanoparticle addition.

Regarding the novel applications of nanoparticles in enhanced oil recovery, the objective of this study is to investigate if nano-sized silica particles have the potential to introduce enhancement in several aspects of surfactant properties particularly its interfacial and adsorption behaviors. Two types of hydrophilic and slightly hydrophobic fumed silica nanoparticles are used in conjunction with sodium dodecyl sulfate. Extensive series of interfacial tension and adsorption measurement experiments are performed. The results indicate that surfactant interfacial and adsorption properties are interestingly influenced by the addition of silica particles. Inclusion of both nanoparticles into surfactant solution causes contrasting interfacial behaviors in low and high surfactant concentrations. The adsorption of surfactant molecules on the rock surface is generally reduced in the presence of nanoparticles except for some highly concentrated surfactant solutions.