Synthesis, luminance and ultraviolet resistance of a copolymer phosphor of Eu-complex and siloxane in near UV-based LED

Re(I) Complexes as Backbone Substituents and Cross-Linking Agents for Hybrid Luminescent Polysiloxanes and Silicone Rubbers

This study focuses on the synthesis of hybrid luminescent polysiloxanes and silicone rubbers grafted by organometallic rhenium(I) complexes using Cu(I)-catalyzed azido-alkyne cycloaddition (CuAAC). The design of the rhenium(I) complexes includes using a diimine ligand to create an MLCT luminescent center and the introduction of a triple C≡C bond on the periphery of the ligand environment to provide click-reaction capability. Poly(3-azidopropylmethylsiloxane-co-dimethylsiloxane) (N₃-PDMS) was synthesized for incorporation of azide function in polysiloxane chain. [Re(CO)₃(MeCN)(5-(4-ethynylphenyl)-2,2′-bipyridine)]OTf (Re1) luminescent complex was used to prepare a luminescent copolymer with N₃-PDMS (Re1-PDMS), while [Re(CO)₃Cl(5,5′-diethynyl-2,2′-bipyridine)] (Re2) was used as a luminescent cross-linking agent of N₃-PDMS to obtain luminescent silicone rubber (Re2-PDMS). The examination of photophysical properties of the hybrid polymer materials obtained show that emission profile of Re(I) moiety remains unchanged and metallocenter allows to control the creation of polysiloxane-based materials with specified properties.

Tunable white light emission of an anti-ultraviolet rare-earth polysiloxane phosphors based on near UV chips

A novel white-light copolymer matched with 365 nm chips is prepared by bonding the vinyl-functionalized complexes Eu(TTA)₂(Phen)(MAA), Tb(p-BBA)₃(UA) and Zn(BTZ)(UA) to polysiloxaneprepolymer(synthesized by polycondensation of vinyltrimethoxysilane and diphenylsilanediol) through a technical route of polymerization after coordination. Its structure was characterized by infrared and ultraviolet. Under the excitation of 365 nm, when the ratio of the tricolor complexes is controlled to be 0.5: 3: 1.5, white light copolymer with CIE color coordinates of (0.327, 0.321) was obtained and packaged to get white light LED devices. After aging, the CIE color coordinates of the device change from (0.325, 0.329) to (0.341, 0.348), the color rendering index changes from 91 to 88, and the correlated color temperature changes from 5967 K to 5612 K. The loss of brightness is only 10.4%, which shows good resistance to UV aging. Moreover, the initial decomposition temperature of the copolymer is 235°C. The above results show that the bonding-type anti-ultraviolet copolymer phosphor has potential application in near ultraviolet LEDs.

Multi-Functional Luminescent Coating for Wood Fabric Based on Silica Sol-Gel Approach

Environmentally friendly protection coatings have obtained increasing attention for their use in wooden materials, which can be destroyed easily when exposed to outdoor environments. A series of silane sol coatings coordinated with Eu³⁺ was prepared by hydrolyzing silane compounds. The obtained luminescent coating with three-dimensional net structure showed excellent optical, anti-ultraviolet aging, and thermal stability. The hybrid silane-modified compound coating was well-distributed on the wood by Si–O bonds to prevent its removal. The compound coating could stave off the decomposition of wood by converting ultraviolet light into red light and a charring action can endow the wood with thermal stability at high temperature, demonstrating the improvement of fire resistance and radiation residence following prolonged exposure to ultraviolet light, proving its excellent anti-ultraviolet aging properties.