Formation of Polyaniline (PANI) multilayer film using humic acid as the bridging agent: Screening on the fabrication technique

The application of polyaniline (PANI) in flexible electronic devices has received increased attention due to its environmental stability, electrical conducting properties, and ease of production. While the electrical conductivity of a PANI film can be altered by modifying the number of PANI layers, this study aims to compare two techniques, namely ex-situ and in-situ, for the fabrication of PANI multilayer film. For the ex-situ technique, PANI was formed separately before being drop-casted on a filter paper; on the other hand, for the in-situ technique, polymerization of aniline into PANI and attachment of PANI on a filter paper was allowed to occur simultaneously. In both techniques, humic acid was used as the bridging agent. Results showed that the in-situ direct growth technique produced PANI multilayer film with good uniformity, lesser cracking, and detachment. On the other hand, the ex-situ drop-casting technique resulted in PANI film with very poor uniformity, irregular thickness, and severe detachment.