Binding of Sodium Dodecyl Sulfate to Some Polyethyleneimines and Their Ethoxylated Derivatives at Different pH Values. Electromotive Force and Microcalorimetry Studies

Abstract

Electromotive force and isothermal titration microcalorimetry measurements have been carried out to study the interactions of sodium dodecyl sulfate (SDS) with polyethyleneimines (PEI's) and some ethoxylated PEI's at different pH's. In all cases the polymers show a remarkable affinity toward SDS. The SDS concentration at the onset of binding decreases with decreasing pH. At low pH's phase separation similar to that observed for strong polyelectrolyte/oppositely charged surfactant systems occurs presumably as a consequence of the protonation of the N atoms in the polymer to form a polycation. The SDS range over which phase separation occurs decreases as the size of the ethoxylated chains increases, and for the polymer with the longest ethoxylated chain no precipitation occurs. In many cases where phase separation occurs, as more SDS is added the polymer/surfactant complex often resolubilizes and binding proceeds until the polymer becomes saturated with bound SDS. For any given polymer at this limiting stage in the binding, the number of surfactant molecules bound per mole of polymer is independent of pH. In addition both the charged and uncharged N atoms as well as the pendant ethoxylated chains make significant contributions to the binding process.

Derivatizing weak polyelectrolytes—Solution properties, self-aggregation, and association with anionic surfaces of hydrophobically modified poly(ethylene imine)

“…Such phase separation of oppositely charged polymers and surfactants can be avoided by grafting water soluble oligomeric groups such as poly(ethylene oxide) to the polymer [35,36]. In such poly(ethoxylated) derivatives, the hydrogen atoms attached to the primary and secondary nitrogen are replaced by an ethoxylated chain.…”

The Interaction between Hexadecyltrimethylammonium Bromide to Poly (Ethylene Glycol) with Different Molecular Weights and Some Schiff-Bases Investigated by Surfactant Ion Selective Electrode

“…[13][14][15][16][17][18] The membrane comprises a specially conditioned poly vinyl chloride (PVC) contains of 0.1% COOH from Montefibre and a commercially available polymeric plasticizer (Elvaloy 742) from Du pont. In order to make membranes selective to HTAB, the respective PVC are neutralized by the oppositely charged HTAB ions before use.…”

“…These conditioning and casting steps were optimized and we used optimized amount of materials. [13][14][15][16][17][18] EMF Measurements. The surfactant membrane electrode selective to HTAB used to determine the concentration of monomer surfactant and counterions, respectively, by measuring their EMF relative to a commercial sodium (corning 476211) reference electrode and also bromide ion (corning solid-state ISE 30-35-00) selective electrode.…”

Adsorption of Xylan onto Cellulose Fibers Pretreated with Cationic Polyelectrolyte and Its Effect on Paper Properties

“…However, the change in frequency was low for highly charged linear polymers, indicating that these polyelectrolytes adsorb in a flat conformation to cover the cellulose surface more effectively. Branched PEI adsorbed more on cellulose surface than highly charged linear polyelectrolytes such as poly-DADMAC, since it gave thicker adsorbed layer (Li et al 2000). CS, which has a highly branched amylopectin as its main component, showed the highest frequency change among the polymers tested.…”