Research On Microwave-assisted Establishment Of Polyacrylamide-based Efficient Amorphous Polymeric Phosphorescent Materials With Ultralong Afterglow

Distinguished characteristics like diverse molecular design and favorable processibility,non-conjugated amorphous polymeric phosphorescent materials with persistent lifetime and intensive luminescence have been potentially applied in various fields like biology and chemistry sensor,anti-counterfeiting and OLED.Though,complex synthesis procedure,high cost,temperature,humidity and oxygen-sensitive to room temperature phosphorescence restrict its significant application.In this paper,the simple synthesis method of microwave power assistance helped obtain the pure polymer as the host component to copolymerize or blend with organic luminophore and nanomaterials since the alternation of MWP parameters and polymerization conditions.The polymer system established on polyacrylamide was conducted and ultralong room temperature phosphorescence in appropriate proportion and condition was realized to explore the luminescence mechanisms and significant application.The main content of this paper was divided into the following three parts.Part 1: under the condition of microwave power-assisted method,the changing factor of MWP,precipitation rate,amount of initiator and solvent,post-treatment temperature and comparsion to other synthesis method result in polyacrylamide with various luminescence properties.The analysis and research of photophysics property and molecular weight test indicated the microwave power fastens the reaction rate of polymerization and the molecular energy absorption,which facilitates the aggregation and clustering state of molecule and polymer,the polyacrylamide obtained with high molecular weight instantly.Simultaneously,heteroatom and functional groups like carbonyl promotes the possibility of intersystem crossing(ISC),stabilizes the triplet excitons,inhibits the non-radiational transition and displays with intense triplet emission at 414 nm,442 nm and 462 nm and the corresponding triplet lifetime were 3.17 s,3.05 s and 3.29 s.Part 2: Based on the optimized device parameters and reaction conditions discussed in Part 1,microwave power assisted the copolymerization of host component acrylamide with organic luminophore,vinyl carbazole,styrene and methyl methacrylate with C=C at different molar ratios respectively.As the results showed that through the appropriately adjustment of the proportions,binary copolymer obtained by the organic luminophore with aromatic ring structure,heteroatoms and functional groups containing lone pairs of electrons and acrylamide realized the ultralong lifetime of 4.06 s,3.89 s and 3.96 s at 414 nm,442 nm and 462 nm.It indictated that enhanced hydrogen-bonding network was synergistically constructed by the vinyl carbazole and matrix polymer.The rigidified polymer system consequently brings about the intense emission and ultralong triplet lifetime.Part 3: G-A binary copolymer and G-Copolymer ternary polymer synthesized with acrylamide,binary copolymer Poly(VCZ-A)in molar ratio of 1:25 and graphene oxide in certain concentration.Amongthese,2G-Poly(VCZ-A)displayed ultralong triplet lifetime at 420 nm,440 nm and 470 nm whose triplet lifetime are respectively 4.98 s,4.15 s and4.23 s.Well dispersed graphene oxide overcome the effect of aggregation and stacking as well as the hydrophilic groups such as carbonyl,epoxy above the planer and hanging in the side chain facilitates the formation of hydrogen-bonding network.Appropriate proportion of graphene oxide dispersion participated in the polymerization stabilizes the aggregation of polymer,strengthen the phosphorescent emission and reach the best performance of ternary polymer.