This study explores the interaction of the surfactant benzyldimethyltetradecylammonium chloride (BAC-C₁₄) with gold-coated quartz crystal microbalance (QCM) sensors in CO₂-saturated brine, aiming to understand its adsorption and desorption behavior. Four bulk concentrations of BAC-C₁₄ in 1 wt.% NaCl brine were evaluated relative to the critical micelle concentration (CMC): 0.25x, 0.50x, 0.75x, and 1x CMC. Quartz crystal microbalance with dissipation (QCM-D) enabled real-time monitoring of both BAC-C₁₄ adsorbed mass and its inhibitor film properties. As BAC-C₁₄ bulk concentration was increased from 0.25x to 1x CMC, the total, steady-state adsorbed mass of surfactant increased linearly. All concentrations exhibited dissipation values below 1x10‾⁶, indicating the formation of rigid films. First-order kinetic modelling was applied to the QCM-D mass response to quantify adsorption kinetics. The model provided an excellent fit to experimental results below the CMC where Langmuir kinetic assumptions are assumed to be valid. The Langmuir model was also used to predict the desorption response of the surfactant, which was validated using the QCM-D by displacing the inhibited brine in the QCM flow cell with uninhibited brine. A reversible adsorption–desorption process was observed at all concentrations below CMC, consistent with theoretical predictions based on Langmuir kinetics, with slight discrepancies being observed at CMC. This discrepancy was primarily attributed to the difficulty in achieving a high-quality fit for the adsorption-dominated response at the CMC, due to the rapid increase in surface coverage, rather than to any inherent irreversibility in the adsorption process itself. The study highlights the complementary characteristics of the QCM-D in its ability to support the fundamental understanding of the interfacial and kinetic behavior of corrosion inhibitors.
CORE (COnnecting REpositories)
CORE (COnnecting REpositories)