The static adsorption of CE, which is a highly ethoxylated nonionic surfactant, was studied on different minerals using high-performance liquid chromatography (HPLC) combined with an evaporative light scattering detector (ELSD). Of particular interest is the surfactant adsorption in the presence of CO because it can be used for foam flooding in enhanced oil recovery applications. The effects of the mineral type, impurities, salinity, and temperature were investigated. The adsorption of CE on pure calcite was as low as 0.01 mg/m but higher on dolomite depending on the silica and clay content in the mineral. The adsorption remained unchanged when the experiments were performed using a brine solution or 0.101 MPa (1 atm) CO, which indicates that electrostatic force is not the governing factor that drives the adsorption. The adsorption of CE on silica may be due to hydrogen bonding between the oxygen in the ethoxy groups of the surfactant and the hydroxyl groups on the mineral surface. Additionally, thermal decomposition of the surfactant was severe at 80 °C but can be inhibited by operating in a reducing environment. Under reducing conditions, adsorption of CE increased at higher temperatures.

LB adsorption on calcite surfaces was found to be significantly increased when blended with IOS or L38 since it forms surfactant complexes that partition to the surface. However, the total adsorption of the LB-IOS-L38 solution on dolomite decreased from 3.09 mg/m to 1.97 mg/m when blended together compared to summing the adsorption values of individual surfactants, which highlights the importance of mixed surfactant association.