Preparation Of Eu³⁺/Tb³⁺ Bridged Polysilsesquioxane And Research Of Luminescence Sensor Properties

Bridged polysilsesquioxanes?BPS?are a new class of hybrid organic-inorganic materials with special properties,whose monomer is generally composed of a variable organic bridging group and trifunctional silyl groups.These materials combine the properties of inorganic and organic materials,which make them present a series of excellent properties.Additionally,BPS is believed to be ideal matrices because they can allow for the high loading of lanthanide complexes and their flexible processability.The research on Ln³⁺-containing BPS is mainly focused on the structure and morphology control of solid material and the transparent films with good luminescent monochromatic.In this paper,we prepared a series of Ln³⁺-containing BPS gels and films with tunable luminescent and the dual-emission wet gel was used for organic amine detection.The main content is as follow:1.A BP precursor,consisting of a C₃-symmetrical benzene central core moiety,capable of sensitizing the luminescence of Eu³⁺and Tb³⁺is reported.Tunable luminescent gels Ln@BP?Ln=Eu/Tb?were facilely prepared by mixing the as-synthesized precursor and Ln³⁺ions in appropriate solvents.By either changing the Eu³⁺/Tb³⁺molar ratio or altering the excitation wavelength,the emission colors of the final gels can be finely tuned.Among them,the dual-emission gel Eu₁₀Tb₂₀@BP can be used as an effective ratiometric luminescent sensor for distinguishing amines with lower pKa?<5?from those with higher pKa?>9?and has the ability of specific recognition of aromatic amine.This strategy can effectively overcome the shortcomings of single-emission transition,which lay a solid foundation for accurate and reliable organic amines sensing in the environment.2.The above-mentioned luminescent gel was dried at 50?for several hours to obtain multi-colored luminescent xerogel?Ln@BP-x?.Meanwhile,the influence of molar ratio of Eu³⁺/Tb³⁺and excitation wavelength on their luminescence properties was studied.Both of them are able to emit multi-colored luminescence?from red via yellow to green?and even the pure white light,which are available for preparing luminescent powders and WLED and have more commercial potential.Moreover,the uniform,transparent and colorful luminescent film?Ln@BP-f?can be facilely implemented by drop-casting of the Ln³⁺complexes ethanol solution onto quartz substrate.