Carbon Nanofibers Functionalized with Amide Group for Ammonia Gas Detection.

This paper presents a new sensing material derived from carbon nanofibers (CNF) functionalized with carboxylic acid first, before further modified with amide functional group. This sensing material was used in the detection of ammonia gas at room temperature. Modified CNF was prepared via Fischer Esterification using dodecylamine as functionalizing reactant. The modified CNF was characterized by field emission-scanning electron microscopy attachment with energy dispersive X-ray (FESEM-EDX) analysis to confirm the attachment of carboxylic and amide functional group. Based on characterization result, CNF successfully modified with the carboxylic and amide functional group by exhibit alteration in their morphology and elemental composition. Then, modified CNF was deposited on interdigitated transducer (IDT) by drop casting method and placed in a customized chamber with electrical feed through occupied with outlet/inlet gas. The resistance of modified CNF upon injection of ammonia gas was monitored with a digital multimeter and compared with the resistance of pristine CNF. Based on the result, modified CNF showed a better response and higher sensitivity than pristine CNF at room temperature. [ABSTRACT FROM AUTHOR]