Harmonizing conjugated and non-conjugated emission for amorphous blue organic afterglow through copolymerization and aggregation engineering

Abstract

Organic afterglow with ultralong room-temperature phosphorescence (OURTP) has inspired extensive attentions recently, but remains a intrinsic challenge in boosting OURTP performance with simultaneously elongated lifetime (τp) and improved quantum yields...

High-Quality Circularly Polarized Organic Afterglow from Nonconjugated Amorphous Chiral Copolymers

“…By comparing the absorption bands of CD and PAM, the 470−538 nm phosphorescence should be due to the absorption of CD in 280−320 nm (Figure S22), while the 400−440 nm emissions are related to the excitable PAM between 310 and 350 nm. 38 The same phenomenon was observed in PAMCN (Figure S21). This two-species emission behavior of the copolymers also suggests that the energy transfer between them is rather weak.…”

“…Thus, two different emitting species were confirmed in the copolymer of PAMCD . By comparing the absorption bands of CD and PAM , the 470–538 nm phosphorescence should be due to the absorption of CD in 280–320 nm (Figure S22), while the 400–440 nm emissions are related to the excitable PAM between 310 and 350 nm . The same phenomenon was observed in PAMCN (Figure S21).…”

“…The copolymerization is performed using acrylamide and chiral cinchona alkaloids with different feeding ratios from 1 to 20 mol ‰ initiated by sodium sulfite and ammonium persulfate in an aqueous solution (0.7 M) under an argon atmosphere (Figure a,b). , After vigorous stirring at room temperature for 12 h and refluxing for 2 h, the copolymers were obtained by precipitation in methanol and subsequent purification procedures to ensure that highly pure materials were achieved. The chiral copolymers of poly­(acrylamide- co -cinchonidine) ( PAMCD ), poly­(acrylamide- co -cinchonine) ( PAMCN ), poly­(acrylamide- co -quinidine) ( PAMQD ), and poly­(acrylamide- co -quinine) ( PAMQN ) were transformed from powders to flake films by aggregation engineering through dissolving in pure water, followed by slow evaporation to remove the water at 70 °C for 12 h. This two-step treatment was named CCAE.…”

“…Prompted by these considerations, we use the cinchona alkaloids with multiple chiral centers as monomers to copolymerize with acrylamide through random free radical polymerization (Figure a and Schemes S1 and S2). It should be noted that acrylamide is famous in designing CTE materials, and polyacrylamide ( PAM ) has shown varied organic afterglow lifetime and color depending on different synthetic conditions. , These PAM -based chiral copolymers are expected to exhibit a CTE-featured organic afterglow with CPL properties for high-performance CPOA.…”

Stable and ultralong room-temperature phosphorescent copolymers with excellent adhesion, resistance, and toughness

“…Polymer-based pRTP materials have drawn special attention in recent years due to their superiorities, such as ease of preparation, good biocompatibility, tunable mechanical properties, and flexible processing methods (22)(23)(24)(25)(26). The general approach for the preparation of pRTP polymeric systems is to chemically or physically introduce phosphors into polymer matrixes such as polyvinyl alcohol (PVA) (27)(28)(29), polymethyl methacrylate (PMMA) (30), polyacrylamide (31), polyacrylonitrile (32), and epoxy polymers (33). In these systems, the molecular motion of phosphors can be effectively restrained by polymeric rigid structure and strong interactions between chromophores and the matrixes, thus enabling pRTP activation of phosphors.…”