Polymer Long Persistent Luminescent Materials Constructed By Crosslinking Strategy And Performance Characterization

Room temperature phosphorescence materials have broad application prospects in information encryption,dynamic anti-counterfeiting,chemical sensing and biological imaging.In particular,intrinsic pure organic room temperature phosphorescence materials not only get rid of the shackles of metal elements but also have good biocompatibility.However,due to the poor structural rigidity of polymer materials and the rapid non-radiative relaxation of triplet excitons,the preparation of this kind of ultralong room temperature phosphorescence material is faced many challenges.Based on the current research on polymer matrix doping and copolymerization cross-linking,this work aims to solve the above problems and develop a pure organic room temperature phosphorescence material with long lifetime and tunable color.The main work is as follows:1)Amido atypical long persistent luminescent materials.Because of the strong intramolecular and intermolecular hydrogen bonds in acrylamide,it can be introduced into the system to improve the structural rigidity,Considering that the hydrogen bond structure is too sensitive to water molecules,the covalent bond was introduced to cooperate with hydrogen bonds to prepare a series of cross-linked atypical luminescent polymer systems.The luminescent properties of polymers are controlled by adjusting the construction of the hydrogen bonding ability of amide molecules and the degree of cross-linking process to regulate.AM315 achieved room temperature phosphorescence emission of up to 8 s under the excitation wavelength of 287 nm.The materials were realized the emission from blue to green after being fumigated by steam for 20 min based covalent cross-linking network.The polychromatic response under different excitation wavelengths can also be realized in this kind of material.This unique luminous characteristic has been successfully applied in the field of information anti-counterfeiting.2)Intrinsic long persistent luminescence based on PVA skeleton.Hydrogen bond networks can be formed by the hydroxyl groups present in PVA molecules.Different kinds of polychromatic phosphors were introduced into PVA molecular chain segments,using hydrogen bond networks to greatly compress the non-radiative relaxation of luminescent molecules.The next cross-link PVA molecules by boric acid,thus realizing the gradual confinement effect of covalent bond and hydrogen bond network.The intrinsic polychromatic long persistent luminescent polymer with double interaction and cooperation is prepared,which overcomes the phosphorescence quenching caused by strong hygroscopicity in traditional physically doped PVA,and the triplet lifetime can reach 1.26 s at room temperature.This provides a new strategy for the development of ultralong room temperature phosphorescence materials with ultrastability and persistence.