Smart Textile: Electrohydrodynamic Jet Printing of Ionic Liquid-Functionalized Cu₃(HHTP)₂ Metal-Organic Frameworks...

Area of Science:

• Materials Science
• Chemical Engineering
• Sensor Technology

Background:

• Nitric oxide (NO) gas detection is crucial for environmental monitoring and safety applications.
• Existing gas sensors often lack the sensitivity, flexibility, or durability required for real-world deployment.
• Metal-organic frameworks (MOFs) offer promising properties for gas sensing but require functionalization to optimize performance.

Purpose of the Study:

• To develop and characterize a smart textile gas sensor for NO detection.
• To enhance the chemiresistive performance of Cu3(HHTP)2 MOFs using ionic liquid (IL) functionalization.
• To fabricate flexible sensors using electrohydrodynamic jet (e-jet) printing on polylactic acid (PLA) substrates.

Main Methods:

• Synthesis and IL functionalization of Cu3(HHTP)2 MOFs with 1-Ethyl-3-methylimidazolium trifluoromethanesulfonate (EMIM+ Otf-).
• Fabrication of textile sensors via e-jet printing of functionalized MOFs onto electrospun PLA.
• Characterization of sensor performance including conductivity, sensitivity, limit of detection, reversibility, and stability under varying conditions.
• Material analysis using SEM, EDX, FTIR, and XRD.

Main Results:

• IL-functionalized Cu3(HHTP)2 sensors showed a 582× increase in conductivity compared to non-functionalized MOF sensors.
• Sensor sensitivity increased from <5% to ~570% at 100 ppm NO after IL functionalization.
• Achieved a theoretical limit of detection of 3.7 ppm for NO gas across a concentration range of 5-300 ppm.
• Demonstrated partial reversibility and maintained functionality under humid conditions and over extended periods.

Conclusions:

• E-jet printing of IL-functionalized MOFs is a viable method for creating advanced, flexible gas sensors.
• The developed smart textile sensor shows significant potential for NO detection in civilian and military applications.
• This technology has implications for the development of personal protective wearable technologies.