Glassy poly(methacrylate) terpolymers with covalently attached emitters and sensitizers for low-power light upconversion

Abstract

Low‐power light upconversion by triplet–triplet annihilation (TTA‐UC) was only recently demonstrated in glassy polymers and the upconversion efficiency in these materials is typically much lower than in solution. As aggregation of the chromophores was thought to be the culprit, we here report the covalent tethering of a suitable chromophore pair to a polymeric backbone. The new materials were based on the sensitizer‐bearing monomer palladium meso‐phenoxy‐tris(heptyl)porphyrin‐ethylmethacrylate (PdmPH3PMA), which was copolymerized with a diphenylanthrancene methacrylate (DPAMA), as the emitter‐bearing monomer, and methyl methacrylate (MMA) as an optically inert comonomer. The DPA content was kept within a narrow range of 30–37 wt %, while the PdmPH3PMA content was varied between 0.73 and 0.012 wt %. To explore additional compositions, blends of a high‐porphyrin‐content terpolymer with a DPAMA‐MMA copolymer were also prepared. All of the materials studied were processed into thin films by solution‐casting and displayed blue TTA‐UC emission. The UC emission intensity was found to strongly depend on the composition and the underlying effects were investigated through a systematic study. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015, 53, 1629–1639

Red Light Activation of Ru(II) Polypyridyl Prodrugs via Triplet-Triplet Annihilation Upconversion: Feasibility in Air and through Meat

“…Finally, this singlet excited state returns to the ground state by fluorescent emission of a high-energy photon, thereby realizing upconversion. TTA-UC has been demonstrated in various organic, inorganic, and/or supramolecular materials [15,[18][19][20][21][22], as well as in nano-or micro-sized particles [23][24][25]. For biological applications, i.e., for drug delivery and activation [26,27] or bio-imaging [13,[28][29][30][31][32][33], one of the main problems of TTA-UC is its sensitivity to molecular oxygen, which readily quenches the triplet state chromophores involved in the TTA-UC mechanism.…”

Kinetically controlled crystal growth approach to enhance triplet energy migration-based photon upconversion

“…Consequently, the majority of TTA-UC systems have been studied in solution 8,[11][12][13][14][15] or soft polymer matrices, [16][17][18][19][20] in which the TET and TTA processes are mediated by molecular diffusion and collision. Meanwhile, it is desirable for device applications that TTA-UC processes occur in the solid state without molecular diffusion.…”

Progress in side-chain thiophene-containing polymers: synthesis, properties and applications

“…Due to the space limitation, we review only the examples of thiophene based building blocks as a representative because of its ease and diversity on chemistry. Plenty of work on other conjugated building blocks has also been reported [20,23,25,[29][30][31]69,70], and attracted increasing attention. The development on the synthesis of conjugated/non-conjugated bi-functional materials would enhance the properties of current products, and emerging applications will enable these materials a bright future.…”