Polyelectrolytes in Solution and the Stabilization of Colloids

Abstract

Polyelectrolytes are very versatile macromolecular materials that have found more and more applications in several technologies. In this article applications related to their use as (de)stabilizers for colloids are reviewed. Additionally, some theories that deal with colloid stabilization are described. Finally, the rheology of the disperser phase as well as the relationship between the rheology of the whole colloidal system and polyelectrolyte stabilization are discussed.

Streptavidin-coated gold nanoparticles: critical role of oligonucleotides on stability and fractal aggregation

“…The process resulted in a characteristic colour change of the dispersion (from red to blue-violet) which is associated with nanoparticles aggregation (Fig. 4) [49–50]. When the same amount of free biotin was added to AuNP-SA dispersions (i.e., nanoparticles with no immobilized oligonucleotides) no similar changes were observed in the absorbance spectrum (Fig.…”

Soluble dynamic coordination polymers as a paradigm for materials science

“…Between the charged polymers, long-range electrostatic interactions are operative so that structure and property also depend on the ionic strength of the solution. In fact, the charge of the resulting polyelectrolytes may contribute to their stabilization in solution due to repulsion as in colloidal solution [37,38]. Because these compounds are rather soluble in polar solvents, the solvent molecules are also coordinating and compete with the ligands for the metal ions.…”

Biomacromoléculas carboximetiladas: atuação como agentes de estabilização de suspensões aquosas de alumina

“…(Mukhopadhyay;Basu, 2007) Sistemas coloidais se distinguem pelo fato das partículas estabelecerem interações partícula/partícula, partícula/solvente e apresentarem elevada relação área/volume em relação ao meio em que estão dispersas. Uma ilustração de um sistema coloidal é apresentada na Figura 1 (Myers, 1999;Vasconcellos;Pereira;Fonseca, 2005) Como resultado dessas interações, as forças de superfície influenciam fortemente o comportamento do sistema. (Darrel, 2003;2004;Vincent, 1974;Lewis, 2000;Oliveira et al, 2000;Lyckfeldt;Carlstrom, 2009) Figura 1: Desenho esquemático de partículas em diferentes formatos com pelo menos uma dimensão na faixa de colóide: a) placa plana; b) cilíndrica; c) gota.…”