Ammonia sensing and electrical properties based on composite of poly(3-thiopheneacetic acid) and zeolite Y

Abstract

Poly(3-thiopheneacetic acid) (Pth) was synthesised and doped with perchloric acid. The electrical conductivity sensitivity towards ammonia is further improved by introducing Y zeolites into the doped Pth matrix. For the effect of zeolite content, the composite with 10% (v/v) of the Y zeolite gives the highest electrical conductivity sensitivity (Δσ/σ_N2) values when exposed to NH₃. The electrical conductivity sensitivity (Δσ/σ_N2) monotonically increases with increasing Si/Al ratio. The highest electrical conductivity sensitivity of all composites investigated is obtained with the doped Pth/zeolite Y (Si/Al = 80) at the value of (7·46±3·56)×10². The interaction between NH₃ and the doped Pth is shown to be reversible based on the Fourier transform infrared spectra.

Keywords:

• Conductive polymer
• Polythiophene
• Polymer composites
• Ammonia sensors
• Gas sensor
• Zeolite Y

The first author is grateful for the scholarship and the funding of the work by the Petroleum and Petrochemical College. The authors acknowledge the financial supports from the Thailand Research Fund (TRF-RTA), the Conductive and Electroactive Research Unit of Chulalongkorn University, and the Royal Thai Government.