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Abstract Sensor devices using different poly(3,4-ethylene dioxythiophene):poly(4-styrenesulfonate) (PEDOT:PSS) based active layers were fabricated with all solution processes. It was found the devices of pristine PEDOT:PSS presented high response to humidity change, but little response to ammonia (NH 3). In contrast, the DMSO doped PEDOT:PSS devices were nearly insensitive to humidity change, and exhibited significantly improved responsivity to NH 3. Incorporation of AgNWs into the DMSO doped PEDOT:PSS film further enhanced the responsivity to NH 3 , while maintaining insensitivity to humidity changes. The mechanisms for such different sensing properties were revealed. Finally, the fabricated NH 3 and humidity sensors using different PEDOT:PSS based films were integrated with a near field communication (NFC) chip to realize a flexible system, which was able to be attached on the packaging film for monitoring the meat freshness, with the sensing data being read out wirelessly by a smart phone. Graphical abstract Image 1 Highlights •The sensing mechanisms to ammonia and humidity of sensors using different PEDOT:PSS based active layers were revealed. •PEDOT:PSS based humidity insensitive ammonia sensors and ammonia insensitive humidity sensors were fabricated with all solution processes, respectively. •The PEDOT:PSS based ammonia and humidity sensors were integrated with a near field communication (NFC) chip to realize a smart packaging system for monitoring the meat freshness. [ABSTRACT FROM AUTHOR]

For the practical combustion of ammonia (NH 3) in air, ammonia jet entrains the combustion product inside the furnace, and the reaction zone is diluted with a significant amount of H 2 O; thus, the impact of H 2 O on NH 3 oxidation cannot be ignored. In this study, NH 3 oxidation was conducted under N 2 and H 2 O atmospheres in a jet-stirred reactor. Experimental and numerical investigations were conducted to analyze the impact of various parameters, including the temperature, equivalence ratio, H 2 O volume fraction, and residence time. The NO formation is enhanced as T increases, while it is inhibited as Φ or X H2O increases. The N 2 O and NO concentrations are an order of magnitude when T ≤ 1375 K, and the peak N 2 O concentration occurs at T ≈ 1375 K and Φ = 0.5. The presence of 20 % H 2 O reduces NO and N 2 O concentrations by 61.5 % and 29.5 %, respectively, at Φ = 0.5 and T = 1375 K. To reduce NO x formation with an acceptable concentration of unburned NH 3 , the recommended operation condition of NH 3 oxidation is obtained. This study presents a new underlying understanding of the formation of NO x during NH 3 oxidation under N 2 and H 2 O atmospheres. • NH 3 oxidation with wide Φ and high H 2 O concentration is studied in a JSR. • 20 % H 2 O addition reduces NO concentration by 61.5 % at Φ = 0.5 and T = 1375 K. • The peak N 2 O concentration occurs at Φ = 0.5 and T ≈ 1375 K. • The optimal condition with low NO x and unburned NH 3 concentration is obtained. [ABSTRACT FROM AUTHOR]