Effect of Surface Morphology of Electro-spun EPAA Coatings on the H₂S Sensing Performance of Corresponding Interdigitated Electrodes

Abstract

In this article, the fabrication of interdigitated electrode (denoted by IDE) H 2 S sensor based on electroactive polyamic acid (denoted by EPAA) containing oligoaniline in the main chain is first demonstrated. First step involved the synthesis of aminocapped aniline trimer (denoted by ACAT). Subsequently, the EPAA and correspondent electroactive polyimide (EPI) was prepared by reacting ACAT and 4,4′-(4,4′-isopropylidene-diphenoxy)bis(phthliic anhydride (BSAA), followed by characterization. For the study of gas sensing, hydrophilic EPAA was found to show better sensitivity of H 2 S gas at the concentration of 50 ppm on IDE as compared to that of hydrophobic EPI. Therefore, as-prepared EPAA with higher gas sensitivity was chosen to process four distinctive morphological images (film, bead, bead-fiber, and fiber) on IDE through electro-spinning technique for following comparative studies in sensitivity, repeatability, response/recovery time and selectivity of H 2 S gas. The surface image of EPAA upon IDE exhibiting four distinctive morphologies was observed by SEM. The IDE with fiber morphology was found to show the shortest response time and longest recovery time of H 2 S gas as compared to other comparative counterparts. Moreover, IDE coated by four distinctive morphological images of EPAA was all show good repeatability of H 2 S gas sensing at specific concentration range.

Valorization of Agricultural Waste as a Chemiresistor H2S-Gas Sensor: A Composite of Biodegradable-Electroactive Polyurethane-Urea and Activated-Carbon Composite Derived from Coconut-Shell Waste

“…The water contact-angle measurements of PUU-AC0, PUU-AC1, and PUU-AC3 were 79.7°, 73.3°, and 72.2°, respectively, indicating their hydrophilic nature. The hydrophilic groups may have developed intermolecular interactions with polar H 2 S gas, thus increasing the response of the sensor [ 27 , 73 ].…”

“…PANI reinforced with various carbon fillers has been used to improve gas-sensing performance [ 21 , 22 , 23 , 24 , 25 , 26 ]. However, considering the poor solubility of PANI, aniline oligomer-based polymers have attracted intensive research interests in the past decade [ 27 ]. In 2005, Zhao et al designed a floating-gate ion-sensitive field-effect transistor that used doped aniline trimer as a sensing material; this transistor could sense up to 70 ppm of NH 3 gas [ 28 ].…”

“…In 2009, aniline trimer-based polyimide as a H 2 S-gas sensor was presented by Santiago and Yeh et al [ 29 ]. In 2020, Yeh et al reported the effect of the surface morphology of electroactive polyamic acid with aniline trimer in the main chain on H 2 S-gas-sensing performance [ 27 ].…”

H2S-Sensing Studies Using Interdigitated Electrode with Spin-Coated Carbon Aerogel-Polyaniline Composites

“…The redox property of PANI and its derivative polymers make them applicable for electrochemical sensing [ 9 , 10 , 11 ]. Their doping/dedoping property also expands their useability for gas sensing [ 12 , 13 , 14 ]. The first publication related to H 2 S sensing was reported by Monkman in 1995.…”

Comparative Studies of CPEs Modified with Distinctive Metal Nanoparticle-Decorated Electroactive Polyimide for the Detection of UA

“…For instance, Chao and Wang prepared OAEPs that have remarkable electrochemical and electrochromic behavior [ 34 , 35 ]. In 2020, Yeh et al reported an H 2 S gas sensor based on an electroactive polymer containing aniline trimer in the main chain [ 36 ]. Additionally, Huang et al, prepared a polylactide-based OAEP for tissue engineering [ 37 ].…”