scholarly journals Deposition of synthetic and bio-based polycations onto negatively charged solid surfaces: Effect of the polymer cationicity, ionic strength, and the addition of an anionic surfactant

2021 ◽  
Author(s):  
Guzman Solis Eduardo
Keyword(s):  
Ionic Strength ◽  
Anionic Surfactant ◽  
Solid Surfaces

scholarly journals Membrane Filtration of Anionic Surfactant Stabilized Emulsions: Effect of Ionic Strength on Fouling and Droplet Adhesion

2019 ◽  
Vol 3 (1) ◽  
pp. 9 ◽  
Author(s):  
Janneke Dickhout ◽  
Rob Lammertink ◽  
Wiebe de Vos
Keyword(s):  
Ionic Strength ◽  
Anionic Surfactant ◽  
Membrane Fouling ◽  
Flow Cell ◽  
Cellulose Membrane ◽  
Oil Droplets ◽  
Flux Decline ◽  
Cake Layer ◽  
The Impact ◽  
Cellulose Surface

Membranes hold great potential to be used for the successful treatment of oily waste water, but membrane fouling leads to substantial decreases in performance. Here we study the impact of ionic strength on membrane fouling from an emulsion stabilized by the anionic surfactant sodium dodecyl sulfonate (SDS). For this we use a unique combinatorial approach where droplet adhesion to a cellulose surface in a flow cell is compared to membrane fouling (flux decline) on a cellulose membrane. In the initial membrane fouling stages droplet adhesion dominates. While the flow cell demonstrates a high number of droplets adhering especially at high ionic strengths (100 mM NaCl), the strongest flux decline is observed at intermediate (10 mM NaCl) ionic strength. This suggests that the fouling mechanism must be different, with pore blocking expecting to dominate at intermediate ionic strength. At the later fouling stages the porosity of the cake layer plays a key role in the flux reduction. At low ionic strength, oil droplets repel each other strongly and an open, more permeable, cake layer is formed. However at higher ionic strength, a screening of charge interactions leads to a lower porosity and thereby a lower flux. This leads to a clear trend: with a higher ionic strength a higher flux decline is observed. Flux recovery is high at all ionic strengths, in line with the observation in the flow cell that oil droplets can easily be sheared of a cellulose surface at all ionic strengths. This work thus highlights the critical effect of the ionic strength on membrane fouling by anionically stabilized emulsions. Moreover it shows how the use of an optical flow cell can provide key insights to help explain observations in more standard membrane fouling experiments.

Adsorption of Cationic Cellulose Derivatives/Anionic Surfactant Complexes onto Solid Surfaces. I. Silica Surfaces

Langmuir ◽  
2004 ◽  
Vol 20 (5) ◽  
pp. 1753-1762 ◽  
Author(s):  
Eiji Terada ◽  
Yulia Samoshina ◽  
Tommy Nylander ◽  
Björn Lindman
Keyword(s):  
Anionic Surfactant ◽  
Solid Surfaces ◽  
Cellulose Derivatives ◽  
Silica Surfaces

scholarly journals Dissolution-Desorption Dynamics of Strontium During Elution Following Evaporation: pH and Ionic Strength Effects

Water ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1461
Author(s):  
William C. Weaver ◽  
Tohren C. G. Kibbey ◽  
Charalambos Papelis
Keyword(s):  
Ionic Strength ◽  
Environmental Fate ◽  
Breakthrough Curves ◽  
Solid Surfaces ◽  
Environmental Behaviors ◽  
Low Concentrations ◽  
Strontium 90 ◽  
Plutonium Production ◽  
Strontium Cation

Radioactive strontium-90 (90Sr2+) is a fission byproduct of uranium and plutonium production, and therefore understanding its environmental fate is of particular importance for predicting the evolution of long-term risk from historical releases. The nonradioactive strontium cation, Sr2+, is a chemical analog for 90Sr2+ that is often used in studies designed to understand the environmental behaviors of 90Sr2+. The focus of this work was on understanding the dynamics of remobilization of strontium following evaporation to dryness in porous media. Evaporation is ubiquitous in the unsaturated zone, and has the potential to significantly impact the dynamics of transport by driving adsorption or precipitation on solid surfaces. For this work, a series of transport experiments were conducted examining the behavior of strontium over a range of pH values, ionic strengths, and concentrations. Saturated transport experiments were conducted, followed by experiments designed to examine the release and transport following evaporation to dryness. Results show increasing saturated retardation with increasing pH, decreasing ionic strength, and decreasing concentration, with the concentration exhibiting the strongest effect. Breakthrough curves at low concentrations were also found to be consistent with significant rate-limited desorption. Remobilization elution curves measured following evaporation to dryness exhibited the high initial effluent concentrations, exceeding the influent strontium concentration, most likely caused by the initial dissolution and accumulation of strontium by the advancing solution. Concentrations at later times were found to be largely consistent with the dynamics of saturated transport for the systems studied.

scholarly journals Contact-mediated triggering of lamella formation by Dictyostelium amoebae on solid surfaces

1988 ◽  
Vol 91 (3) ◽  
pp. 367-377 ◽  
Author(s):  
N.F. Owens ◽  
D. Gingell ◽  
J. Bailey
Keyword(s):  
Ionic Strength ◽  
Charge Density ◽  
Dictyostelium Discoideum ◽  
Electrostatic Potential ◽  
Streaming Potential ◽  
Potential Method ◽  
Solid Surfaces ◽  
Specific Chemical ◽  
Amine Groups ◽  
Chemical Groups

Amoebae of the slime mould Dictyostelium discoideum form broad ultrathin cytoplasmic lamellae by a centripetal contractile process soon after they have spread on certain solid surfaces. We have investigated the surface requirements for initial triggering of this contact-mediated signalling system. The lamellar response is not normally evoked by glass, but is seen on glass covalently derivatized with paraffinic chains, as well as on glass covalently derivatized with amine groups and on glass bearing adsorbed polylysine. We have recorded the frequency of the lamellar response on these surfaces as a function of ionic strength and pH, and have measured the electrostatic potentials of the surfaces by the streaming potential method. Using these data we have concluded that the general trigger for the lamellar response is not a ‘simple’ physical or chemical property of the substrata: it is not dependent on specific chemical groups, degree of hydrophobicity, electrostatic potential, or charge density, taken as isolated factors. It seems likely that triggering is dependent on the overall energetics of cell-substratum interaction.

Adsorption of Cationic Cellulose Derivative/Anionic Surfactant Complexes onto Solid Surfaces. II. Hydrophobized Silica Surfaces

Langmuir ◽  
2004 ◽  
Vol 20 (16) ◽  
pp. 6692-6701 ◽  
Author(s):  
Eiji Terada ◽  
Yulia Samoshina ◽  
Tommy Nylander ◽  
Björn Lindman
Keyword(s):  
Anionic Surfactant ◽  
Solid Surfaces ◽  
Cellulose Derivative ◽  
Silica Surfaces ◽  
Hydrophobized Silica
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