Fullerene-Doped Poly(ionic liquids) as Small Molecular Gas Sensors-Control of Intermolecular Interactions

Area of Science:

• Materials Science
• Chemical Sensing
• Nanotechnology

Background:

• Poly(ionic liquids) (PILs) are emerging materials for chemical sensing applications.
• Fullerenes (C60, C70) are known for their unique electronic properties and potential in composite materials.

Purpose of the Study:

• To investigate the interaction of specific gaseous analytes with PILs and their fullerene nanocomposites.
• To evaluate the potential of these materials as sensitive layers in gas sensors.

Main Methods:

• Synthesis and characterization of two PILs (P4,4,4,4SPA and P4,4,4,8SPA) and their nanocomposites with C60 and C70.
• Electrochemical impedance spectroscopy (EIS) to study analyte-PIL interactions.
• Semiempirical quantum mechanical calculations (xTB-GFN2) to understand detection mechanisms.

Main Results:

• PILs and their fullerene nanocomposites interact with various C2 gaseous analytes (acetaldehyde, bromoethane, ethanol, acetic acid, acetonitrile).
• Fullerene doping significantly enhances the sensor response.
• Analyte exposure alters the diffusion coefficient, with specific trends for different functional groups.
• Hydrogen bonding and proton transfer are key mechanisms in gas detection.

Conclusions:

• PILs, especially when doped with fullerenes, demonstrate significant potential for gas sensing applications.
• The choice of cation and fullerene significantly influences the sensing performance.
• Understanding the interaction mechanisms, such as hydrogen bonding, is crucial for designing advanced gas sensors.