Ionic conductivity of solid polyelectrolyte complexes with varying water content: application of the dynamic...

Area of Science:

• Materials Science
• Physical Chemistry
• Polymer Science

Background:

• Polyelectrolyte complexes (PECs) are versatile materials with tunable properties.
• Understanding ion transport in PECs is crucial for their application in various fields.
• Previous studies on ion conductivity in PECs have shown complex behaviors dependent on composition and hydration.

Purpose of the Study:

• To systematically investigate the dc conductivity of solid polyelectrolyte complexes (PECs) of the type xPSS·(1-xPSS)PDADMA.
• To determine the influence of temperature, PSS content, and water content on PEC conductivity.
• To explore the applicability of the dynamic structure model to describe ion transport in PECs.

Main Methods:

• Systematic study of dc conductivity as a function of temperature, PSS content, and water content.
• Analysis of small ion incorporation (Na+, Cl-) and their mobility within the PEC matrix.
• Application and validation of the dynamic structure model for glassy ion conductors.

Main Results:

• In hydrated PECs, chloride ions (Cl-) are mobile and govern conductivity in PDADMA-rich compositions (xPSS < 0.5).
• Sodium ions (Na+) determine conductivity in PSS-rich compositions (xPSS > 0.5).
• Conductivity dependence on composition follows power-laws, consistent with the dynamic structure model, for both Cl- and Na+-rich PECs.

Conclusions:

• The dynamic structure model successfully describes ion transport in PECs, indicating ions move through ion-specific pathways.
• Hydration significantly enhances ion mobility, particularly for chloride ions.
• The findings provide fundamental insights into ion conduction mechanisms in polyelectrolyte systems.