Study of polymer–metal ion–membrane interactions in liquid-phase polymer-based retention (LPR) by continuous diafiltration

Effect of dense CO2 on polymeric reverse osmosis and nanofiltration membranes and permeation of mixtures of macauba oil (Acrocomia aculeata) and CO2

“…In this approach, the work of adhesion of a liquid phase (W) onto a solid substrate can be expressed according to Equation ( It is actually difficult to measure the contact angle accurately, since the process of wetting when the liquid spreads on a surface is affected by some factors as the viscosity of the fluid, the roughness and heterogeneity of the surface, the temperature of both the fluid and the substrate, the volume of the drop deposited and the specific interactions of the fluid and the surface [13]. Therefore, it is only possible to measure an apparent contact angle, which is not actually that to be used in Equation (3).…”

“…Therefore, it is only possible to measure an apparent contact angle, which is not actually that to be used in Equation (3). On a rough surface, the apparent contact angle is related to the ideal contact angle by the Wenzel's equation [13,14] θ φ θ cos cos…”

Adsorption of linear polymers on polyethersulfone membranes: Contribution of divalent counterions on modifying of hydrophilic–lipophilic balance of polyelectrolyte chain

“…These have been used at conjunction with ultrafiltration membrane during batch and crossflow filtrations [21,28]. Likewise, polyethersulfone (PES) composite membranes have been used in these experiments; these membranes are hydrophilic, with high water permeability and can be used in a wide range of pH [28].…”

“…These have been used at conjunction with ultrafiltration membrane during batch and crossflow filtrations [21,28]. Likewise, polyethersulfone (PES) composite membranes have been used in these experiments; these membranes are hydrophilic, with high water permeability and can be used in a wide range of pH [28]. However, a decrease of permeability is observed as the metal ion concentration is increased and the polymer reaches its maximum retention capacity (r max : maximum amount of metal ions bound to the polymer per amount of polymer).…”

“…Experimental evidences showed that adsorption of PAA on PES membranes depends on increase of divalent-metal ions added during the continuous diafiltration by enrichment method at constant pH (pH 6.0), an increase in metal ions concentration leads to a screening of the charges along the PAA chain being the polymer-membrane interaction negligible in absence of divalent metal ions [28]. As concentration of metal ions is increased the flux is decreased and polymer molecules in solution experiments conformational changes which should be associated with the features of the fouling layer produced and closely related to the adsorption mechanism which is taking place; however, the focus of attention has been centered in the conformational changes experimented by the polymer chain adsorbed on the surface independently of conformational changes of the polymer molecules in solution.…”