Colloidal polyion complexation from sodium poly(acrylate) and poly(vinyl ammonium) chloride in aqueous solution

Abstract

The colloidal polyion complex formed from sodium poly(acrylate) (NaPA) and poly(vinyl ammonium) chloride (PVACl) is almost stoichiometric but is slightly charged owing to the adsorption of an excess of the polyelectrolyte component onto the neutral complex. The charge stabilizes the colloidal polyacrylate-poly(vinyl ammonium) complex in an aqueous solution of a non-stoichiometric mixture of NaPA and PVACl, and the aggregation number of the colloidal complex increases as the stoichiometric composition is approached. This colloidal polyion complexation is an irreversible process, and the aggregation number depends on the method used to mix the NaPA and PVACl solutions. On the basis of the experimental results, we propose a simple model for colloidal polyion complex formation.

Structural Determinants of the Stability of Enzyme‐Responsive Polyion Complex Nanoparticles Targeting Pseudomonas aeruginosa’s Elastase

“…This difference can be explained from the tendency of the latter nanoparticles to aggregate, as observed when their D H was monitored over time (Figure S8): Whereas PIC nanoparticles prepared from peptides P2 SH – P4 SH displayed the same size over time, the D H of the nanoparticles made from P1 SH increased by 50% after 10 days, which was the time that passed between the preparation of these PIC nanoparticles and their SLS analysis. Nevertheless, the R g / R H values found for this collection of nanoparticles are in agreement with those reported in the literature for other PIC nanoparticles (1.0–1.6) ,. These R g / R H ratios, which are higher than the value expected for a solid sphere (0.775), have been rationalized by the high polydispersity of PIC nanoparticles and their tendency to aggregate in some cases ,.…”

“…Nevertheless, the R g / R H values found for this collection of nanoparticles are in agreement with those reported in the literature for other PIC nanoparticles (1.0–1.6) ,. These R g / R H ratios, which are higher than the value expected for a solid sphere (0.775), have been rationalized by the high polydispersity of PIC nanoparticles and their tendency to aggregate in some cases ,. Both of these factors act as a bias towards higher R g / R H values, making the elucidation of the internal structure of these nanomaterials extremely difficult.…”

Polyion complex (PIC) particles: Preparation and biomedical applications

“…General models rationalise that PIC formation is primarily based on the electrostatic attraction between oppositely charged polyions [3] , [18] , [23] , [24] . However, it has been demonstrated that the increase in entropy upon counterion release from polyelectrolytes is the main driving force in PIC particle self-assembly [25] , [26] .…”

Reversible Vesicle–Spherical Micelle Transition in a Polyion Complex Micellar System Induced by Changing the Mixing Ratio of Copolymer Components

“…In what follows, the hydrophobicity of MA is assumed to be so strong that C 0± (d) = 0. 35,36 Thus, we can specify the composition of the aqueous solution of the AP−MP mixture in terms of the six variables,…”

“…If we regard the micellization as a kind of the phase separation and the hydrophobic core of the micelle formed by AP and MP as the coexisting concentrated phase, we can specify the composition of the solution in terms of the molar concentrations of A – ( C 0– (d) ), M + ( C 0+ (d) ), and MA ( C 0± (d) ) in the coexisting dilute phase and of A – ( C 0– (c) ), M + ( C 0+ (c) ), and MA ( C 0± (c) ) in the coexisting concentrated phase (or the hydrophobic core), as shown in Figure . In what follows, the hydrophobicity of MA is assumed to be so strong that C 0± (d) = 0. , Thus, we can specify the composition of the aqueous solution of the AP–MP mixture in terms of the six variables, C 0– (d) , C 0+ (d) , C 0– (c) , C 0+ (c) , C 0± (c) , and the volume fraction of the concentrated phase (the hydrophobic cores) Φ (c) in the solution.…”