Calcium Carbonate-Modified Surfaces by Electrocrystallization To Study Anionic Surfactant Adsorption

Abstract

In view of enhanced oil recovery, the adsorption behavior of surfactants is usually monitored on smooth model rock surfaces using quartz crystal microbalance with dissipation (QCM-D). However, this is an impractical situation as the effect of the surface roughness of reservoir rocks and its role in surfactant adsorption processes are not yet completely understood. The coupling of electrochemical techniques and QCM-D in one analysis setup (EQCM-D) provides a new methodology to explore complex surfactant adsorption processes. In this work, a uniform, rough, and well-covered model CaCO 3 surface was obtained on gold and platinum sensors to model carbonate rocks. This was achieved by the electrochemically formed hydroxide ions in the presence of bicarbonate and calcium ions, by which the controlled deposition of CaCO 3 resulted in sensor surface coverages in the range 35− 40%. Before using the deposited CaCO 3 surfaces, the adsorption of anionic surfactant alcohol alkoxy sulfate (AAS) on a smooth commercially available CaCO 3 surface was studied with varying CaCl 2 concentrations. For the first time, the structure and characteristics of the formed AAS layer were quantitatively described, indicating the formation of an incomplete bilayer. Compared to the smooth CaCO 3 surface, an increase in the frequency shift from 5 to 15 times was observed in sensors covered with rough CaCO 3 deposit. This observation was primarily attributed to the rougher surfaces that possess more adsorption sites for AAS binding and also to the effect of liquid trapping, inducing additional frequency shifts. The obtained results show that surfactant adsorption on rough surfaces was vastly different from that on smooth surfaces, and they provide a better understanding of the adsorption behavior of surfactants to mineral surfaces.

Calcium carbonate: controlled synthesis, surface functionalization, and nanostructured materials

“…To this aim, the last decade or so has witnessed many types of in situ or post-modification methods having been developed to tune the surface polarity, hydrophilicity, oleophobicity, stability, and reactivity of CaCO 3 MNPs. 33,34 CaCO 3 MNPs with distinct surface properties can thus be obtained and used to produce CaCO 3 -based or CaCO 3incorporated structured materials that have growing potential and applications in biomaterials and biomedicines, and environmental applications. 35,36 It has been well established that CaCO 3 particles are stable at pH 7, whereas they dissolve and release carbon dioxide (CO 2 ) gas under acidic conditions, 37 allowing them to be functionalized with targeting molecules or polymers for targeted pH-responsive drug/gene/protein delivery.…”

Comprehensive review on surfactant adsorption on mineral surfaces in chemical enhanced oil recovery

“…46,47 For example, atomic force microscope (AFM) has considerably contributed to better understanding of dimensions, morphologies, and orientations of adsorbed surfactant layers. [48][49][50][51][52] More recently, quartz crystal microbalance with dissipation monitoring (QCM-D) has been applied to investigate the adsorption behavior of surfactants, [53][54][55][56][57][58][59][60][61][62] which can be also coupled with AFM, spectroscopic ellipsometry (SE), and surface plasmon resonance (SPR) techniques. 52,[63][64][65][66] Therefore, to realize effective transport of surfactants into reservoirs, it is of great importance to understand surfactant adsorption on mineral surfaces.…”

A Laboratory Protocol to Evaluate Effective Permeability Alteration by Adding Surfactants in Fracturing Fluids

“…This reduced adsorption in SS-1 may be attributed to stronger electrochemical repulsion between the hydrophilic heads of the surfactant molecules and the negatively charged quartz minerals, which constitute ∼40% of the rock minerals. 51 Nonionic surfactants, lacking surface charges, rely on van der Waals forces and hydrogen bonding for adsorption, potentially explaining the higher adsorption observed in SS-3. 20 4.1.4.…”