Chemical reaction and phase transformation mechanism of electrospun iron (III) acetylacetonate-polyacrylonitrile fibers during pre-oxidation process

Low-temperature pre-oxidation of electrospun metal-compound-incorporated carbon fibers can involve phase transitions and chemical reactions. However, their mechanics remain unclear. In this work, a mixture of poly-acrylonitrile (PAN) and iron acetylacetonate is subjected to electrospinning followed by a pre-oxidation process at 230 degrees C, producing PAN fibers loaded with iron compounds. Our detailed investigations shed light on the mechanisms of phase transitions and associated chemical reactions during the pre-oxidation process. Our find-ings reveal that PAN undergoes cyclization during pre-oxidation, and that crystalline iron acetylacetonate within PAN fibers transforms into amorphous FeO and Fe2O3.