Amperometric method for determining the degree of complexation of polyelectrolytes with cationic surfactants

Counterion binding to protamine polyion at a polarised liquid–liquid interface

“…Voltammetry of the polarised liquid-liquid interfaces (LLI) and liquid membranes (LM) has provided a useful insight into the interfacial behaviour of water-soluble polyelectrolytes including perfluorsulfonate ionomer Nafion [6], poly(diallyldimethyl-ammonium chloride) and polyethyleneimine [7], synthetic polyammonium ions [8], oligosized polystyrene sulfonate [9], as well as of biopolymers DNA [10], cytochrome c [11], ribonuclease A [11], heparin [12][13][14][15] and protamine (a heparin antidote) [16][17][18]. One particular aspect of this behaviour is the counterion binding to the polyion, which leads to the facilitated polyion transfer and to a measurable shift in the voltammetric peak potential [6][7][8][9][10][11][12][13][14][15][16][17][18].…”

“…One particular aspect of this behaviour is the counterion binding to the polyion, which leads to the facilitated polyion transfer and to a measurable shift in the voltammetric peak potential [6][7][8][9][10][11][12][13][14][15][16][17][18]. The other aspect is the adsorption of the polyion at LLI, which has been indicated by the current response on the reverse scan of the polyion transfer [8,13,16,18], or by the appearance of the adsorption peak [6,7].…”

Channel Flow Configuration for Studying the Kinetics of Surfactant−Polyelectrolyte Binding

“…This is due to the strong electrostatic and hydrophobic interaction forces between the polyelectrolyte and the ionic surfactants. The interaction thermodynamics of such systems has been widely studied. − However, the kinetics of the interaction is poorly understood, due mainly to the rapid rate of the association reaction. Some published results exist on the polymer (e.g., poly(vinylpyrrolidone) or poly(ethylene oxide)) surfactant (alkanesulfates) systems.…”

Decorating soft electrified interfaces: From molecular assemblies to nano-objects

“…Interfacial behaviour of these species gives very characteristic voltammetric fingerprints: (i) peak to peak separation deviates from 59/z mV; (ii) reverse peaks are terminated by the abrupt drop in current; (iii) charge transfer peak current at macroscopic liquidliquid interface do not follow ∝ √ ( being scan rate) dependency and (iv) shift of the peak position towards higher ∆ for increasing concentration of interfacially active speciesindicating higher resistance to the charge transfer reaction. These indications were observed for electrochemically driven interfacial adsorption of few class of macromolecular species including polyelectrolytes [30][31][32][33][34][35][36][37][38][39], polyamidoamide [40][41][42][43], polypropylenimine [44] and poly-L-lysine [45] dendrimers among others [46,47] peptides [48,49] and proteins [28,[50][51][52][53]. The interfacial adsorption of biological macromolecules brings exciting applications towards the field which are still not sufficiently studied.…”