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Surfactant adsorption and ion exchange on calcite surfaces are investigated by means of flooding experiments in Estaillades limestone cores. We show that, in the 5000 mg/L salinity range, effluent concentrations can be captured in a reactive transport model that includes calcite dissolution, ion exchange, complexation of divalent ions, and the monomer–micelle equilibrium. In this model, ion exchange and adsorption are described by the screening of the negative surface charge by cations and surfactant–divalent ion complexes. We further show that adsorption can be reduced by a factor of 10 by coinjection of surfactant and polyacrylate or a polyacrylate preflush, which is attributed to a combination of divalent ion complexation and adsorption to the rock surface.

Interfaces between complex oxides constitute a unique playground for two-dimensional electron systems (2DESs), where superconductivity and magnetism can arise from combinations of bulk insulators. The 2DES at the LaAlO3/SrTiO3interface is one of the most studied in this regard, and its origin is determined by the polar field in LaAlO3as well as by the presence of point defects, like oxygen vacancies and intermixed cations. These defects usually reside in the conduction channel and are responsible for a decrease of the electronic mobility. In this work, we use an amorphous WO3overlayer to obtain a high-mobility 2DES in WO3/LaAlO3/SrTiO3heterostructures. The studied system shows a sharp insulator-to-metal transition as a function of both LaAlO3and WO3layer thickness. Low-temperature magnetotransport reveals a strong magnetoresistance reaching 900% at 10 T and 1.5 K, the presence of multiple conduction channels with carrier mobility up to 80 000 cm2V–1s–1, and quantum oscillations of conductance.