Novel light-conversion hybrids of SBA-16 functionalized with rare earth (Eu3+, Nd3+, Yb3+) complexes of modified 2-methyl-9-hydroxyphenalenone and 1,10-phenanthroline

Research Progress of Light Wavelength Conversion Materials and Their Applications in Functional Agricultural Films

As new fluorescent materials, light wavelength conversion materials (light conversion agents) have attracted increasing attention from scientific researchers and agricultural materials companies due to their potential advantages in efficiently utilizing solar energy and increasing crop yield. According to the material properties, the light conversion agents can be divided into fluorescent dyes, organic rare-earth complexes, and inorganic rare-earth complexes. The current researches indicates that the fluorescent dyes have relatively high production costs, poor light stability, difficult degradation processes, and easily cause pollution to the ecological environment. The organic rare-earth complexes have short luminescence times, high production costs, and suffer from rapid decreases in luminescence intensity. Compared with fluorescent dyes and organic rare-earth complexes, although rare-earth inorganic complexes have high luminous efficiency, stable chemical properties, and better spectral matching performance, the existing inorganic light conversion agents have relatively poor dispersibility in agricultural films. According to the research on light conversion agents at home and abroad in recent years, this paper first introduces the three common light conversion agents, namely fluorescent dyes, organic rare-earth complexes, and inorganic rare-earth complexes, as well as their uses in agricultural films and their mechanisms of light conversion. At the same time, the preparation methods, advantages, disadvantages, and existing problems of various light conversion agents are classified and explained. Finally, we predict the development trends for light conversion agents in the future by considering six aspects, namely efficiency, cost, compatibility with greenhouse films, light matching, and light transmittance, in order to provide a reference for the preparation of stable and efficient light conversion agent materials.

Exploring polylactide/poly(butylene adipate-co-terephthalate)/rare earth complexes biodegradable light conversion agricultural films

In this work, rare earth europium was combined with different organic ligands to obtain two kinds of rare earth conversion agents, Eu(DBM)₄CPC and Eu(TTA)₃(TPPO)₂. Two kinds of conversion films were successfully prepared by combining them with polylactide and poly(butylene adipate-co-terephthalate). Results showed that the film has excellent light conversion ability and high color purity, and rare earth complexes improved melt flowing property and decreased melt viscosity of blend. At the same time, the elongation at break of the film increased greatly, which could up to 595.0/460.9% in the both machine direction (MD) and transverse direction (TD). The results of GPC show that rare earth complexes can make main chain of PLA scission, which causes rapid molecular weight reduction, and the effect of Eu(DBM)₄CPC on the molecular weight of PLA was more significant than Eu(TTA)₃(TPPO)₂. SEM shows that the complicity of PLA and PBAT has been improved, the dispersed phase of the blend is more uniform. DSC shows that both rare earth complexes can improve the crystallization capacity of PLA. And with the addition of cetylpyridinium chloride could improve the compatibility of rare earth complexes and polymer materials, the light transmittance and hydrophilicity of the film also increased obviously.

Polyacrylamide modified mesoporous SBA-16 hybrids encapsulated with a lanthanide (Eu3+/Tb3+) complex

Novel polymeric mesoporous luminescent hybrids have been synthesized by linking the binary and ternary Ln³⁺ complexes to polyacrylamide-functionalized mesoporous SBA-16 in situ. The excellent luminescent properties of these materials together with the highly ordered mesoporous structure will expand their applications in optical or electronic areas.