Related Experiment Video
Updated: Oct 13, 2025
08:44
Assembly and Characterization of Polyelectrolyte Complex Micelles
Published on: March 2, 2020
11.0K
Interfacial Behavior of Solid- and Liquid-like Polyelectrolyte Complexes as a Function of Charge Stoichiometry.
Hongwei Li1,2, Martin Fauquignon1,2, Marie Haddou1,2
1Centre de Recherche Paul Pascal (CRPP), UMR CNRS 5031, University of Bordeaux, 33600 Pessac, France.
Polymers
|November 13, 2021
Summary
Surface tension measurements reveal how polyelectrolyte complexes (PECs) form. Changes in charge ratio (Z) affect PECs, indicating their structure and phase behavior, crucial for understanding complex formation mechanisms.
Area of Science:
- Colloid and Surface Science
- Polymer Chemistry
- Materials Science
Background:
- Polyelectrolyte complexes (PECs) are formed by the interaction of oppositely charged polymers.
- Understanding PEC formation mechanisms is crucial for their application in various fields.
- Surface activity plays a key role in the self-assembly and properties of PECs.
Purpose of the Study:
- To investigate the surface activity of polyelectrolyte complex (PEC) suspensions.
- To correlate surface tension with the molar charge ratio (Z) in model PEC systems.
- To elucidate the phase behavior and formation mechanisms of PECs.
Main Methods:
- Systematic investigation of PEC surface tension as a function of molar charge ratio (Z).
- Utilized two model PEC systems: PDADMAC/PANa (weakly interacting) and PDADMAC/PSSNa (strongly interacting).
- Employed surface tension measurements and the generalized Young-Laplace method.
Main Results:
- PEC surface tension decreases near charge stoichiometry (Z=1), indicating increased hydrophobicity and surface activity.
- PDADMAC/PANa system exhibits liquid-liquid phase separation (coacervation) at Z=1.
- PDADMAC/PSSNa system shows complete sedimentation, indicating liquid-solid phase separation.
- Surface tension measurements accurately determine charge stoichiometry and detect trace aggregates.
Conclusions:
- Surface tension is a sensitive tool for characterizing PEC formation and structure.
- The study discriminates between different PEC phase behaviors (liquid-liquid vs. liquid-solid).
- Understanding PEC surface activity provides insights into their self-assembly and properties.
Keywords:
complex coacervatesinterfacial tensionliquid–liquid and liquid–solid transitionpendant droppolyelectrolyte complexessurface tensionMore Related Videos
Related Concept Videos
03:13Intermolecular Forces
62.7K
Atoms and molecules interact through bonds (or forces): intramolecular and intermolecular. The forces are electrostatic as they arise from interactions (attractive or repulsive) between charged species (permanent, partial, or temporary charges) and exist with varying strengths between ions, polar, nonpolar, and neutral molecules. The different types of intermolecular forces are ion–dipole, dipole–dipole, hydrogen bonds, and dispersion; among these, dipole–dipole, hydrogen...
62.7K
02:42Aqueous Solutions and Heats of Hydration
15.6K
Water and other polar molecules are attracted to ions. The electrostatic attraction between an ion and a molecule with a dipole is called an ion-dipole attraction. These attractions play an important role in the dissolution of ionic compounds in water.
When ionic compounds dissolve in water, the ions in the solid separate and disperse uniformly throughout the solution because water molecules surround and solvate the ions, reducing the strong electrostatic forces between them. This process...
When ionic compounds dissolve in water, the ions in the solid separate and disperse uniformly throughout the solution because water molecules surround and solvate the ions, reducing the strong electrostatic forces between them. This process...
15.6K
03:37Molecular Shape and Polarity
64.5K
Dipole Moment of a Molecule
64.5K
02:34Comparing Intermolecular Forces: Melting Point, Boiling Point, and Miscibility
47.0K
Intermolecular forces are attractive forces that exist between molecules. They dictate several bulk properties, such as melting points, boiling points, and solubilities (miscibilities) of substances. Molar mass, molecular shape, and polarity affect the strength of different intermolecular forces, which influence the magnitude of physical properties across a family of molecules.
Temporary attractive forces like dispersion are present in all molecules, whether they are polar or nonpolar. They...
Temporary attractive forces like dispersion are present in all molecules, whether they are polar or nonpolar. They...
47.0K
01:06Interfacial Electrochemical Methods: Overview
511
Interfacial electrochemical methods focus on the phenomena occurring at the boundary between an electrode and a solution, as opposed to bulk methods that concentrate on the solution's overall properties. These interfacial methods are classified as either static or dynamic based on the presence of a nonzero current in the electrochemical cell and the consistency of analyte concentrations. Static methods, such as potentiometry, measure the cell's potential without any significant current...
511
03:00Solubility
19.0K
Solution, Solubility, and Solubility Equilibrium
A solution is a homogeneous mixture composed of a solvent, the major component, and a solute, the minor component. The physical state of a solution—solid, liquid, or gas—is typically the same as that of the solvent. Solute concentrations are often described with qualitative terms such as dilute (of relatively low concentration) and concentrated (of relatively high concentration).
In a solution, the solute particles (molecules,...
A solution is a homogeneous mixture composed of a solvent, the major component, and a solute, the minor component. The physical state of a solution—solid, liquid, or gas—is typically the same as that of the solvent. Solute concentrations are often described with qualitative terms such as dilute (of relatively low concentration) and concentrated (of relatively high concentration).
In a solution, the solute particles (molecules,...
19.0K