Electrochemistry of Biosystems
Linking Glucose Oxidation to Luminol-based Electrochemiluminescence using bipolar Electrochemistry
Asymmetric Modification of TiO2 Nanofibers with Gold by Electric-Field-Assisted Photochemistry
Stimuli-responsive microgels for electrochemiluminescence amplification

A. Perro, L. Giraud, N. Coudon, S. Shanmugathasan, B. Goudeau, J.-P. Douliez and V. Ravaine

Journal of Colloid and Interface Science 2019 548, 275-283.

Coacervation is a phase separation process involving two aqueous phases, one solute-phase and one solute-poor phase. It is frequently observed among oppositely-charged polyelectrolyte systems. In this study, we focus on self-coacervation involving a single polymer chain and investigate its potential for encapsulation applications. Negatively charged polyacrylic acid polymer chains were partially cationized using diamine and carbodiimide chemistry affording ampholytes, named PAA-DA, with tunable charge ratio. When dispersed in water, at pH 7, PAA-DA was soluble but a phase separation occurs when decreasing pH close to the isoelectric point. Coacervation is found only for a given amine-to-acid ratio otherwise precipitation is observed. Increasing the pH above 4 yielded progressive destruction of the coacervates droplets via the formation of vacuoles within droplets and subsequent full homogeneous redispersion of PAA-DA in water. However, addition of calcium allowed increasing the coacervate droplet stability upon increasing the pH to 7 as the divalent ion induced gelation within droplets. Moreover, the coacervate droplets present the ability to spontaneously sequestrate a broad panel of entities, from small molecules to macromolecules or colloids, with different charges, size and hydrophobicity. Thanks to the reversible character of the coacervates, triggered-release could be easily achieved, either by varying the pH or by removing calcium ions in the case of calcium-stabilized coacervates. Self-coacervation presents the advantage of pathway-independent preparation, offering a real output interest in pharmacy, water treatment, food science or diagnostics.

JCIS 3

 

Self-coacervation of ampholyte polymer chains as an efficient encapsulation strategy.


Thursday, 02 May 2019
A. Perro, L. Giraud, N. Coudon, S. Shanmugathasan, B. Goudeau, J.-P. Douliez and V. Ravaine Journal of Colloid and Interface Science 2019 548, 275-283. Coacervation is a phase separation process involving two aqueous phases, one solute-phase... Read More...

Kinetics of spontaneous microgels adsorption and stabilization of emulsions produced using microfluidics


Thursday, 02 May 2019
M.-C. Tatry, E. Laurichesse, A. Perro, V. Ravaine and V. Schmitt Journal of Colloid and Interface Science 2019, 548, 1-11. The aim of the paper is to examine the adsorption kinetics of soft microgels and to understand the role off undamental... Read More...

Adsorption of Proteins on Dual Loaded Silica Nanocapsules


Thursday, 02 May 2019
S. Ramalingam, G. Le Bourdon, E. Pouget, A. Scalabre, J. Raghava Rao and A. Perro J. Phys. Chem B 2019, 123 (7), 1708-1717. The design of nanocarriers containing hydrophobic and hydrophilic compounds represents a powerful tool for cocktail... Read More...