Electroactive Poly(amic acid) Films Grafted with Pendant Aniline Tetramer for Hydrogen Sulfide Gas Sensing...

Area of Science:

• Materials Science
• Chemical Sensors
• Electrochemistry

Background:

• Hydrogen sulfide (H2S) is a toxic industrial gas requiring sensitive detection for safety.
• Existing H2S sensors often lack the necessary sensitivity, selectivity, or stability.
• Electroactive polymers offer potential for advanced gas sensing applications.

Purpose of the Study:

• To investigate the impact of pendant aniline tetramer pendant (PEDA) loading on poly(amic acid) (PAA) films for H2S sensing.
• To evaluate the gas sensing performance, including sensitivity, response time, selectivity, and stability, of PEDA-grafted PAA films.
• To establish a promising material platform for practical environmental monitoring and industrial safety.

Main Methods:

• Synthesis and characterization of PEDA-grafted PAA films with varying PEDA loadings.
• Material characterization using Ion trap MS, FTIR, cyclic voltammetry (CV), and four-probe conductivity measurements.
• Gas sensing tests evaluating response to H2S, selectivity against common interferents (SO2, NO2, NH3, CO), repeatability, and long-term stability.

Main Results:

• Successful incorporation of PEDA into EPAA films, confirmed by characterization techniques.
• EPAA3 (3 wt% PEDA) exhibited optimal performance for 10 ppm H2S, with a 591% response and 108 s response time.
• EPAA3 demonstrated excellent selectivity for H2S over other gases and maintained over 80% performance after 16 days.

Conclusions:

• PEDA-grafted PAA films offer a promising combination of processability and redox behavior for H2S sensing.
• The EPAA3 composition provides a balance of sensitivity, durability, selectivity, and reproducibility.
• These PEDA-grafted PAA films represent a viable platform for effective environmental monitoring and industrial safety applications.