Noncovalent grafting of polyelectrolytes onto hydrophobic polymer colloids with a swelling agent

Tuning Nanoparticle Surface Chemistry and Interfacial Properties for Highly Stable Nitrogen-In-Brine Foams

“…For a dilational modulus E > γ/2, foam coarsening is arrested according to Gibbs criterion. ,,, For example, Maestro et al increased the hydrophobicity of silica NPs by adsorbing cationic surfactants on the surface in deionized (DI) water to increase E and arrest foam coarsening. The E of an NP-laden interface has been previously characterized by oil drops or air bubbles , in DI water and oil drops in brine with salinity up to 10 wt % NaCl . To the best of our knowledge, extremely few studies of interfacial rheological properties of the NP-laden interfaces in equilibrium with a bulk brine phase have been reported in high salinity above about 3 wt % NaCl, especially with divalent ions, given the lack of colloidal stability in the brine phase.…”

Polyelectrolyte-grafted Ti3C2-MXenes stable in extreme salinity aquatic conditions for remediation of contaminated subsurface environments

“…12 Furthermore, the proven colloidal stability in the testing medium (API brine) oen employed in the studies on subsurface oil and gas applications strongly suggests new possibilities for using the MXenes, with the graed PEs, as an additive of nanouids for down-hole applicsations such as enhanced oil recovery (EOR) and reservoir characterization. [30][31][32][39][40][41][42]…”

“…1a)this anionic PE has been widely employed in a number of studies relevant to subsurface oil and gas applications. 30,[39][40][41][42] The second PE is a zwitterionic random where DMAPS is a stabilizing unit and AA is an anchoring unit (Fig. 1a).…”

“…30 Furthermore, the resistance of the MXene-g-PEs against undesirable adsorption to model mineral substrates in harsh environments is studied. The overall results suggest that the MXenes graed with the zwitterionic PEs have superior mobility in high salinity media than those graed with relatively well-known sulfonated anionic PEs, 30,[39][40][41][42] which is discussed in terms of the different brush behavior of the graed PEs in the presence of salt ions. Finally, the ability of the MXene-g-PEs of scavenging a model aqueous organic pollutant, methylene blue, is shown.…”

“…55,56 Because of this, PEs containing the AMPS unit have been widely employed for various subsurface oil and gas applications in high-salinity environments. 30,[39][40][41][42] However, this does not mean that the AMPS unit is perfectly free from any specic complexation with divalent counterions. For example, 32 it was recently shown that monodisperse poly(AMPS) brushes end-graed on silica nanoparticles underwent charge inversion by Ca 2+ binding with excess Ca 2+ and even the temperature-dependent "second brush collapse," which describes the signicant brush re-contraction that occurred aer the brushes preliminarily underwent the "rst brush collapse" regime caused by the charge neutralization at relatively lower Ca 2+ concentrations.…”