title: Preparation of electrospun luminescent polyimide/europium nanofibers by simultaneous in situ sol-gel and imidization processes.
abstract: Luminescent polyimide (PI)/europium nanofibers have been successfully prepared by electrospinning combined with an in situ sol-gel technique. The possible reaction mechanism of the simultaneous imidization of polyamide acid and gelation of europium phase was analyzed by thermogravimetric analysis (TG) and differential scanning calorimetry (DSC). The results showed that chemical coupling and noncovalent interaction existed between the polymer and the europium which formed during the preparative process. Fourier-transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), and scanning electronic spectroscopy (SEM) studies also indicated the successful incorporation of europium into PI matrix and various morphologies could be achieved by controlling the calcination temperature and the europium content. Nanofibers with necklace-like structures were obtained after calcination under high temperatures. These PI/europium nanofibers were further demonstrated to have strong fluorescence emission. The intensity ratio for the PI/europium nanofibers, labeled as ((5)D(0)→(7)F(2))/((5)D(0)→(7)F(1)), which is well known as the asymmetry parameter, was lower than that in pure Eu(2)O(3) powder, indicating that there were highly symmetric coordination spheres around europium in the nanofibers.
authors.affiliation: Key Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou, Jiangsu, People's Republic of China.
authors.forename: Si
authors.initials: S
authors.lastname: Cheng
authors.forename: Xiaofei
authors.initials: X
authors.lastname: Li
authors.forename: Sibai
authors.initials: S
authors.lastname: Xie
authors.forename: Yun
authors.initials: Y
authors.lastname: Chen
authors.forename: Li-Juan
authors.initials: LJ
authors.lastname: Fan