Surfactants

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Kerstin Eckert - One of the best experts on this subject based on the ideXlab platform.

  • the influence of negatively charged silica nanoparticles on the surface properties of anionic Surfactants electrostatic repulsion or the effect of ionic strength
    Physical Chemistry Chemical Physics, 2020
    Co-Authors: Milad Eftekhari, Karin Schwarzenberger, Aliyar Javadi, Kerstin Eckert
    Abstract:

    The presence of negatively charged nanoparticles affects the surface activity of anionic Surfactants in an aqueous phase. Recent studies suggest that electrostatic repulsive forces play an important role in increasing the surface activity of Surfactants. However, the addition of nanoparticles also increases the ionic strength of the system, which has a significant impact on the surfactant's properties, e.g. its critical micelle concentration (CMC). To investigate how and to what extent electrostatic forces and ionic strength influence the behavior of ionic Surfactants, the surface tension and elasticity of different solutions were measured using drop profile tensiometry as a function of the surfactant (SDBS), nanoparticle (silica) and salt (KNO3) concentration. It is observed that the surface activity of the Surfactants is mainly influenced by the change in the system's ionic strength due to the presence of nanoparticles. Several characteristic parameters including the equivalent concentration of the surfactant, the CMC and the apparent partial molar area of the adsorbed surfactant are theoretically calculated and further employed to validate experimental observations. Both the nanoparticles and electrolyte decrease the CMC, while the equivalent concentration of the surfactant remains nearly constant. This paper presents a criterion to estimate the possible influence of such forces for nanoparticles of different sizes and mass fractions.

Aliyar Javadi - One of the best experts on this subject based on the ideXlab platform.

  • the influence of negatively charged silica nanoparticles on the surface properties of anionic Surfactants electrostatic repulsion or the effect of ionic strength
    Physical Chemistry Chemical Physics, 2020
    Co-Authors: Milad Eftekhari, Karin Schwarzenberger, Aliyar Javadi, Kerstin Eckert
    Abstract:

    The presence of negatively charged nanoparticles affects the surface activity of anionic Surfactants in an aqueous phase. Recent studies suggest that electrostatic repulsive forces play an important role in increasing the surface activity of Surfactants. However, the addition of nanoparticles also increases the ionic strength of the system, which has a significant impact on the surfactant's properties, e.g. its critical micelle concentration (CMC). To investigate how and to what extent electrostatic forces and ionic strength influence the behavior of ionic Surfactants, the surface tension and elasticity of different solutions were measured using drop profile tensiometry as a function of the surfactant (SDBS), nanoparticle (silica) and salt (KNO3) concentration. It is observed that the surface activity of the Surfactants is mainly influenced by the change in the system's ionic strength due to the presence of nanoparticles. Several characteristic parameters including the equivalent concentration of the surfactant, the CMC and the apparent partial molar area of the adsorbed surfactant are theoretically calculated and further employed to validate experimental observations. Both the nanoparticles and electrolyte decrease the CMC, while the equivalent concentration of the surfactant remains nearly constant. This paper presents a criterion to estimate the possible influence of such forces for nanoparticles of different sizes and mass fractions.

Milad Eftekhari - One of the best experts on this subject based on the ideXlab platform.

  • the influence of negatively charged silica nanoparticles on the surface properties of anionic Surfactants electrostatic repulsion or the effect of ionic strength
    Physical Chemistry Chemical Physics, 2020
    Co-Authors: Milad Eftekhari, Karin Schwarzenberger, Aliyar Javadi, Kerstin Eckert
    Abstract:

    The presence of negatively charged nanoparticles affects the surface activity of anionic Surfactants in an aqueous phase. Recent studies suggest that electrostatic repulsive forces play an important role in increasing the surface activity of Surfactants. However, the addition of nanoparticles also increases the ionic strength of the system, which has a significant impact on the surfactant's properties, e.g. its critical micelle concentration (CMC). To investigate how and to what extent electrostatic forces and ionic strength influence the behavior of ionic Surfactants, the surface tension and elasticity of different solutions were measured using drop profile tensiometry as a function of the surfactant (SDBS), nanoparticle (silica) and salt (KNO3) concentration. It is observed that the surface activity of the Surfactants is mainly influenced by the change in the system's ionic strength due to the presence of nanoparticles. Several characteristic parameters including the equivalent concentration of the surfactant, the CMC and the apparent partial molar area of the adsorbed surfactant are theoretically calculated and further employed to validate experimental observations. Both the nanoparticles and electrolyte decrease the CMC, while the equivalent concentration of the surfactant remains nearly constant. This paper presents a criterion to estimate the possible influence of such forces for nanoparticles of different sizes and mass fractions.

Han-lin Meng - One of the best experts on this subject based on the ideXlab platform.

  • Improved Methane Hydrate Formation and Dissociation with Nanosphere-Based Fixed Surfactants As Promoters
    ACS Sustainable Chemistry & Engineering, 2016
    Co-Authors: Fei Wang, Han-lin Meng
    Abstract:

    The fixation of Surfactants is very important in surfactant-promoted gas hydrate formation. In this work, three Surfactants were fixed on the surface of polystyrene nanospheres through emulsion polymerization (named as Surfactant@PSNS) and then used in methane hydrate formation and dissociation, which were sodium dodecyl sulfate (SDS), cetyltrimethylammonium bromide (CTAB), and dodecyl alcohol ethoxylates (AEO). The fixation of the Surfactants could reduce the induction periods and improve the apparent densities and storage capacities of the formed hydrates, especially at low surfactant concentrations. During hydrate dissociation, the fixation of Surfactants resulted in the hydrates dissociating more slowly. The methane recoveries were improved from 76.37%, 27.87%, and 32.35% to 87.55%, 43.43%, and 60.20% for the fixation of SDS, CTAB, and AEO, respectively. Moreover, with Surfactants fixed, the foam generation during hydrate dissociation was obviously controlled.

  • Improved Methane Hydrate Formation and Dissociation with Nanosphere-Based Fixed Surfactants As Promoters
    2016
    Co-Authors: Fei Wang, Han-lin Meng, Guo-qiang Liu, Gang Guo, Sheng-jun Luo, Rong-bo Guo
    Abstract:

    The fixation of Surfactants is very important in surfactant-promoted gas hydrate formation. In this work, three Surfactants were fixed on the surface of polystyrene nanospheres through emulsion polymerization (named as Surfactant@PSNS) and then used in methane hydrate formation and dissociation, which were sodium dodecyl sulfate (SDS), cetyltrimethylammonium bromide (CTAB), and dodecyl alcohol ethoxylates (AEO). The fixation of the Surfactants could reduce the induction periods and improve the apparent densities and storage capacities of the formed hydrates, especially at low surfactant concentrations. During hydrate dissociation, the fixation of Surfactants resulted in the hydrates dissociating more slowly. The methane recoveries were improved from 76.37%, 27.87%, and 32.35% to 87.55%, 43.43%, and 60.20% for the fixation of SDS, CTAB, and AEO, respectively. Moreover, with Surfactants fixed, the foam generation during hydrate dissociation was obviously controlled

Karin Schwarzenberger - One of the best experts on this subject based on the ideXlab platform.

  • the influence of negatively charged silica nanoparticles on the surface properties of anionic Surfactants electrostatic repulsion or the effect of ionic strength
    Physical Chemistry Chemical Physics, 2020
    Co-Authors: Milad Eftekhari, Karin Schwarzenberger, Aliyar Javadi, Kerstin Eckert
    Abstract:

    The presence of negatively charged nanoparticles affects the surface activity of anionic Surfactants in an aqueous phase. Recent studies suggest that electrostatic repulsive forces play an important role in increasing the surface activity of Surfactants. However, the addition of nanoparticles also increases the ionic strength of the system, which has a significant impact on the surfactant's properties, e.g. its critical micelle concentration (CMC). To investigate how and to what extent electrostatic forces and ionic strength influence the behavior of ionic Surfactants, the surface tension and elasticity of different solutions were measured using drop profile tensiometry as a function of the surfactant (SDBS), nanoparticle (silica) and salt (KNO3) concentration. It is observed that the surface activity of the Surfactants is mainly influenced by the change in the system's ionic strength due to the presence of nanoparticles. Several characteristic parameters including the equivalent concentration of the surfactant, the CMC and the apparent partial molar area of the adsorbed surfactant are theoretically calculated and further employed to validate experimental observations. Both the nanoparticles and electrolyte decrease the CMC, while the equivalent concentration of the surfactant remains nearly constant. This paper presents a criterion to estimate the possible influence of such forces for nanoparticles of different sizes and mass fractions.