Porphyrin Functional Materials And Their Sensing Properties

Porphyrin and its derivatives have been widely studied as sensing materials benefit from thei excellent optical property, chemical stability and easy modification. In this work, porphyrii functioned molecule P1 was synthesized with the properties of metal ions induced fluorescenc(?) ratiometric sensing. It was used as a metal ion sensor with high sensitivity and selectivity Meanwhile, porphyrin functioned filter paper and porphyrinated polyimide honeycomb film; and nanofibers were fabricated, and were used for sensing applications. The main results of this work are summarized as followed:Porphyrin functioned molecule (P1) was synthesized from 5-(4-aminophenyl)-10,15,2(-triphenylporphyrin (ATPP), and was used as zinc ion sensing probe. It showed fluorescence emission shift from 649 nm to 603 nm upon adding with zinc ion solution. Based on the fluorescence ratiometric sensing mechanism, the porphyrin derivative showed excellent sensing property to zinc ion with high selectivity.Cobalt porphyrin (CoTPP) is well-known for its specific interaction properties to nitric substances through axial coordination. Dansyl piperazine (DP) with fluorescence property was coordinated on axial position of CoTPP, and resulted in fluorescence quenching. Adsorption of CoTPP-DP coordination compounds onto TiO2 particles pre-covered natural cellulose filt(?) paper yielded a "turn on" fluorescence gaseous ammonia sensor with high sensitivity and fast response.Porphyrinated polyimide (PPIs) copolymers were synthesized by introducing porphyrir moieties into polymer backbones. PPIs honeycomb films were fabricated by breath figure method. It can be found from the field emission scanning electron microscope (FESEM) images that after introducing porphyrin units, the honeycomb films show decreased pore diameters and change from monolayer to multilayer structure, which is due to the interaction of porphyrin units with water, as demonstrated by calculations based on density functional theory (DFT). The well-ordered porous PPI films exhibit outstanding thermal stability. Furthermore, the films treated at different temperatures show remarkable fluorescence quenching behavior toward HCl gas with quenching ratios higher than 72%, whereas it is only about 50% for the corresponding dense film.PPIs nanofibers were fabricated by electrospinning technique. It can be found from the field emission scanning electron microscope (FESEM) images that the average diameter of nanofiber is about 200 nm. Based on the specific interaction with mercury ion (Hg2+), the PPIs nanofibers were chosen as Hg2+ adsorption materials. After treated by PPIs nanofibers, Hg2+ with 200 ppb can be reduced by 90%, and the adsorption property still kept stable even in condition of pH from 4.0 to 11.0.