Preparation And Properties Of Amorphous Room Temperature Phosphorescent Materials Based On Phenylboronate

In the past decades,room temperature phosphorescence(RTP)materials,which can emit afterglow for a period of time,from seconds to hours,have attracted the attention of scientists because of their unique photophysical properties and the broad development prospects in many fields,such as biological imaging,organic light emitting diodes,information storage and encryption,photodynamic diagnosis and treatment,and sensing equipment.Phenylboronate derivatives,have the characteristics of non-coplanar,and can effectively promote the transition from excited singlet state to excited triplet state through spin-orbit coupling,thus showing excellent phosphorescence performance at room temperature.In this thesis,a series of room temperature phosphorescent film materials based on phenylborate derivatives were prepared,and their optical properties and applications in the field of information encryption were studied.1.Firstly,3-acrylamidophenylboronic acid(3-AAPBA)was synthesized by acylation of 3-aminophenylboronic acid.Two membrane materials,AM-PBA and NMA-PBA,were prepared by copolymerization of 3-AAPBA with acrylamide(AM)and N-hydroxymethylacrylamide(NMA),with potassium persulfate(KPS)as an initiator and N,N-methylene bisacrylamide(MBA)as a crosslinking agent.These membrane materials were soaked in methanol solution of Gallic acid to obtain AM-PBA-G and NMA-PBA-G.The optical properties of the films were characterized in detail by macroscopic observation,excitation-emission fluorescence spectrum,excitation-emission phosphorescence spectrum,fluorescence attenuation spectrum,phosphorescence attenuation spectrum,excitation-fluorescence emission three-dimensional spectrum,excitation-phosphorescence emission three-dimensional spectrum and time-dependent luminescence spectrum.The results showed that the AM-PBA-G and NMA-PBA-G films exhibited room temperature phosphorescence properties.At room temperature,they emitted blue light under the irradiation of 365nm ultraviolet light.After turning off the excitation source,they emitted yellow-green afterglow with a maximum duration of 5.6 s.The phosphorescence lifetime of the material was up to 629.29 ms.2.AM-PBA and NMA-PBA were immersed in methanol solution of 1,8-dihydroxynaphthalene and 1,8-diaminonaphthalene to obtain four types of membrane materials,namely AM-PBA-NH₂,AM-PBA-OH,NMA-PBA-NH₂and NMA-PBA-OH.The optical properties of the films were characterized in detail by macroscopic observation,excitation-emission fluorescence spectrum,excitation-emission phosphorescence spectrum,fluorescence attenuation spectrum,phosphorescence attenuation spectrum,excitation-fluorescence emission three-dimensional spectrum,excitation-phosphorescence emission three-dimensional spectrum and time-dependent luminescence spectrum.The results showed that these films exhibited excellent room temperature phosphorescent properties.At room temperature,the material emitted blue-white light under the irradiation of 365 nm ultraviolet light.After turning off the excitation source,the materials emitted a yellow-green afterglow.The phosphorescence lifetime of the membrane materials was up to 987.38 ms,which is higher than that of most pure organic amorphous room temperature phosphorescence materials reported.In addition,the membrane materials were p H responsive,and the phosphorescence disappeared under alkaline condition and was recovered under acidic condition.Using this feature,the multiple encryption of information was realized by means of Morse cipher.