The influence of negatively charged silica nanoparticles on the surface properties of anionic surfactants: electrostatic repulsion or the effect of ionic strength?

Eftekhari, Milad; Schwarzenberger, Karin; Javadi, Aliyar; Eckert, Kerstin

doi:10.1039/c9cp05475h

Cited by 44 publications

(24 citation statements)

References 50 publications

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“…The dynamic surface tension of the aqueous system in the presence of NPs (0.25 wt %), CTAB (0.5 CMC), and NPSCs (0.25 wt % NP + 0.5 CMC CTAB) is measured using PAT. Consistent with previous studies, 52,53 our results showed that hydrophilic silica NPs do not change the surface tension of pure water (orange triangles in Figure 3a). However, it is observed that adding the same amount of NPs to a 0.5 CMC CTAB solution increases the surface tension of the mixture significantly (see Figure 3a, blue squares vs purple diamonds).…”

Section: Resultssupporting

confidence: 93%

Interfacial Behavior of Particle-Laden Bubbles under Asymmetric Shear Flow

et al. 2021

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The behavior of moving bubbles has mostly been studied in an axisymmetric flow field. To extend the knowledge to practical conditions, we investigate the interfacial and hydrodynamic properties of bubbles under asymmetric shear forces. Experiments are performed with a buoyant bubble at the tip of a capillary placed in a defined shear flow in the presence of surfactants, nanoparticles, and glass beads. The response of the interface to the surrounding asymmetric flow is measured under successive reduction of the surface area. Profile analysis tensiometry is utilized to investigate the dynamic surface tension and the surface rheology of the surfactant- and nanoparticle-laden interfaces. Microscopic particle image and tracking velocimetry are used to study the bulk flow and the interfacial mobility of the buoyant bubble. According to our results, the rotational component of the shear flow provokes an interfacial flow, which redistributes the adsorbed surfactants and particles at the interface. In the presence of NPSCs, a contiguous network of particles forms at the interface through densification of surface structures. We show that this interconnected nanoparticle network eventually stops the interfacial flow and decreases the mobility of the glass beads at the interface. The immobilization of the interface is characterized by a dimensionless number, defined as the ratio of the interfacial elasticity to bulk shear forces. This number provides an estimate of the interfacial forces required to impose interfacial immobility at a defined flow field. Our findings can serve as a basis to formulate boundary conditions for refined modeling and to predict the hydrodynamics of bubbles and droplets.

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Section: Resultssupporting

confidence: 93%

Interfacial Behavior of Particle-Laden Bubbles under Asymmetric Shear Flow

et al. 2021

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“…This leads to micellization even at lower concentrations. Another possible reason for the decrease in the CMC is the increase in the ionic strength of the solution in the presence of nanoparticles which could enhance the surfactant micellization [27] . However, when the NPs concentration was raised to 300 ppm, an increment in the CMC value was noted to 2172 ppm.…”

Section: Resultsmentioning

confidence: 99%

“…Another possible reason for the decrease in the CMC is the increase in the ionic strength of the solution in the presence of nanoparticles which could enhance the surfactant micellization. [27] However, when the NPs concentration was raised to 300 ppm, an increment in the CMC value was noted to 2172 ppm. The sudden increase in the CMC at higher SCN concentrations could be due to the advent of nanoparticles' agglomeration.…”

Section: Effect Of Scn On Critical Micelle Concentration and Its Vari...mentioning

confidence: 99%

Evaluation of Silicon Carbide Nanoparticles as an Additive to Minimize Surfactant Loss during Chemical Flooding

et al. 2022

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Surfactant flooding is a prolific enhanced oil recovery technique. It alters the rock fluid interfacial interactions between reservoir fluids and rocks. However, a pair of impeding factors often limit the economic viability of the process and need to be optimized. The first is the surfactant loss on the adsorbent surface due to adsorption making it a potential environmental problem. The second is the Critical Micelle Concentration (CMC) which governs the amount of surfactant pumped. This study aimed to minimize the surfactant loss and the CMC, thereby optimizing the flooding efficiency and reducing the environmental concerns for nanoparticle applications. To achieve this, Silicon Carbide nanoparticles (SCN) were employed as additives to the surfactant solution. It was observed that the use of SCN reduces the surfactant adsorption by as much as 44 % and the critical micelle concentration by 14 %. The studies also observed that the concentration of SCN required to get these results is dramatically (more than 25 times) lower than previously reported literature on other nanoparticles. To adsorption isotherm studies provide an insight into the type of adsorption taking place. The adsorption isotherm follows the Langmuir model.

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“…This could lead to a decrease in the electrostatic repulsive force between the surfactant molecules, forcing the surfactant to form micelles even at a lower concentration. 47 , 48 The reduction in the CMC of the surfactant could be attributed to an increase in the ionic concentration in the solution in the presence of nanoparticles that would promote the micellization of the surfactant even at a lower concentration. 49 , 50 Similar results were obtained in the present study, and the presence of CSNs would have increased the ionic strength of the surfactant solution; as a result, the micellization of the surfactant appeared even at lower concentrations.…”

Section: Resultsmentioning

confidence: 99%

Application of Novel Colloidal Silica Nanoparticles in the Reduction of Adsorption of Surfactant and Improvement of Oil Recovery Using Surfactant Polymer Flooding

2021

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Surfactant polymer flooding is one of the most common chemical enhanced oil recovery techniques, which improves not only the microscopic displacement of the fluid through the formation of the emulsion but also the volumetric sweep efficiency of the fluid by altering the viscosity of the displacing fluid. However, one constraint of surfactant flooding is the loss of the surfactant by adsorption onto the reservoir rock surface. Hence, in this study, an attempt has been made to reduce the adsorption of the surfactant on the rock surface using novel colloidal silica nanoparticles (CSNs). CSNs were used as an additive to improve the performance of the conventional surfactant polymer flooding. The reduction in adsorption was observed in both the presence and absence of a polymer. The presence of a polymer also reduced the adsorption of the surfactant. Addition of 25 vol % CSNs effectively reduced the adsorption of up to 61% in the absence of a polymer, which increased to 64% upon the introduction of 1000 ppm polymer in the solution at 2500 ppm of the surfactant concentration at 25 °C. The adsorption of surfactant was also monitored with time, and it was found to be increasing with respect to time. The adsorption of surfactant increased from 1.292 mg/g after 0.5 days to 4.179 mg/g after 4 days at 2500 ppm of surfactant concentration at 25 °C. The viscosity, surface tension, and wettability studies were also conducted on the chemical slug used for flooding. The addition of CSNs effectively reduced the surface tension as well as shifted the wettability toward water-wet at 25 °C. Sand pack flooding experiments were performed at 60 °C to access the potential of CSNs in oil recovery, and it was found that the addition of 25 vol % CSNs in the conventional surfactant polymer chemical slug aided in the additional oil recovery up to 5% as compared to that of the conventional surfactant polymer slug.

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The influence of negatively charged silica nanoparticles on the surface properties of anionic surfactants: electrostatic repulsion or the effect of ionic strength?

Abstract: The presence of negatively charged nanoparticles affects the surface activity of anionic surfactants in an aqueous phase. This effect is mainly caused by the change in ionic strength of the system resulted from the addition of nanoparticles.

Cited by 44 publications

References 50 publications

Interfacial Behavior of Particle-Laden Bubbles under Asymmetric Shear Flow

Interfacial Behavior of Particle-Laden Bubbles under Asymmetric Shear Flow

Evaluation of Silicon Carbide Nanoparticles as an Additive to Minimize Surfactant Loss during Chemical Flooding

Application of Novel Colloidal Silica Nanoparticles in the Reduction of Adsorption of Surfactant and Improvement of Oil Recovery Using Surfactant Polymer Flooding

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