Highly Frustrated Poly(ionic liquid) ABC Triblock Terpolymers with Exceptionally High Morphology Factors

Area of Science:

• Polymer Science
• Materials Science
• Electrochemistry

Background:

• Poly(ionic liquid)s (PILs) are crucial for polymer electrolytes.
• Understanding structure-property relationships in PILs is vital for optimizing ion conductivity.
• ABC triblock terpolymers offer complex architectures for tailored material properties.

Purpose of the Study:

• To synthesize and characterize a series of poly(ionic liquid) ABC triblock terpolymers.
• To investigate the diverse morphologies arising from different terpolymer compositions.
• To establish the relationship between morphology and ion conductivity in these materials.

Main Methods:

• Synthesis of 17 unique poly(S-b-VBMIm-TFSI-b-HA) compositions.
• Morphological characterization using small-angle X-ray scattering (SAXS) and transmission electron microscopy (TEM).
• Ion conductivity measurements and calculation of morphology factors.

Main Results:

• Successfully synthesized 17 PIL ABC triblock terpolymer compositions.
• Observed nine distinct morphologies, including disordered, cylindrical, lamellar, gyroid, and superlattice structures.
• Demonstrated significant impact of morphology on ion conductivity, with a hexagonal superlattice yielding an exceptionally high morphology factor of 2.0.
• Confirmed the spheres-in-lamellae morphology via SAXS and TEM.

Conclusions:

• The study presents the first systematic investigation of highly frustrated single-ion conducting ABC triblock terpolymers with diverse morphologies.
• Morphology plays a critical role in determining ion transport efficiency.
• The findings provide a foundation for designing highly conductive polymer electrolytes by controlling morphology.