Study On Room Temperature Phosphorescence Of Palladium Porphyrin Induced By Composite Matrix Of Polymer And Surfactant

Room temperature phosphorescence（RTP）has the advantages of long lifetime,large stokes shift and high signal-to-noise ratio.It has widespread application prospects in bioimaging,chemical sensing,optoelectronic devices and so on.However,due to the factors such as the transition inhibition of phosphors and the long lifetime of triplet,it is usually necessary to design and synthesize phosphors with higher intersystem transition probability,or develop protective matrices to obtain room temperature phosphorescence.Due to the complexity of the design and synthesis process of phosphors,current room temperature phosphorescence enhancement studies have generally focused on the development of new protective matrices.The traditional room temperature phosphorescent protective matrices also has the problem of complicated design and synthesis,and the disadvantage of poor biocompatibility limits the application in biological field.In view of these deficiencies,natural polymer Gelatin and triblock copolymer HO（CH₂CH₂O）₁₃（CH₂CH（CH₃）O）₃₀（CH₂CH₂O）₁₃H（L64）,which are easy to obtain and biocompatible,and surfactant sodium deoxycholate（NaDC）were used to construct a polymer/surfactant composite matrix to induce the room temperature phosphorescence of meso-tetra（carboxyl phenyl）porphin palladium（Pd-TCPP）.The mechanisms of inducing room temperature phosphorescence were aslo studied.The results obtained are as follows:1.A NaDC/Gelatin gel matrix was constructed to induce room temperature phosphorescence of Pd-TCPP.The results show that NaDC/Gelatin can induce high-intensity room temperature phosphorescence of Pd-TCPP without deoxygenation or the presence of heavy atoms.The optimum conditions are as follows:the concentration of Pd-TCPP is 1.25x10^-5mol/L,the concentration of NaDC is 4x10^-3mol/L,the concentration of Gelatin is 4.5 wt%and the pH of the system is 8.0.2.The mechanism of inducing room temperature phosphorescence of Pd-TCPP was characterized by infrared spectroscopy,scanning electron microscopy,thermodynamic calculation and so on.The results show that Pd-TCPP is in the micelles of NaDC through hydrogen bonding and hydrophobic interaction,then Pd-TCPP/NaDC micelles enter the hydrophobic cave structures of Gelatin.The double ordered structure of NaDC and Gelatin,which greatly reduces the non-radiative transition probability of Pd-TCPP,is the main reason to induce the high-intensity room temperature phosphorescence.The results also show that the system is temperature sensitive,which has a reversible"on-off"effect between 25°C and 70°C.3.A NaDC/L64 solution matrix was constructed to induce room temperature phosphorescence of Pd-TCPP.The results show that NaDC/L64 can induce high-intensity room temperature phosphorescence of Pd-TCPP without the presence of heavy atoms.The optimum conditions are that the concentration of Pd-TCPP is 6×10^-6mol/L,the concentration of NaDC is 6×10^-3mol/L,the concentration of L64 is 10g/L,the pH of the system is 7.3,the concentration of Na₂SO₃ is 0.01mol/L and the reagent addition sequence is Pd-TCPP,L64,NaDC,Na₂SO₃,H₂O,HCl.4.The mechanism of inducing room temperature phosphorescence of Pd-TCPP was characterized by transmission electron microscopy,UV-visible absorption spectroscopy,infrared spectroscopy and so on.The results show that both NaDC and L64 form a spherical micelle structure,which can improve the dispersion of Pd-TCPP and prevent Pd-TCPP from aggregation.The micelle structure with hydrophobic cores can reduce the non-radiative transition probability of Pd-TCPP.The study also found that the system could be used for Cu²⁺detection,which provides a new idea for Cu²⁺detection.