Preparation And Properties Of Eu³⁺ Ternary Complex Modified Cotton Fiber And Wood-based Materials

Biomass-based materials such as cotton fiber and poplar are susceptible to moisture,temperature,biological bacteria,light and other conditions.At present,the main content of biomass-based material modification is to improve its functionality by physical or chemical means,endow biomass with new properties and extend its service life.It is well known that organic-inorganic hybrid composites are utilized,which can impart more excellent properties(such as mechanical properties,optical and magnetic response)without changing their morphology.This study is based on the current situation of poplar cotton/wood fiber surface functional modification and the basic principle of Eu3+ternary coordination chemical reaction to functionalize and improve cotton and poplar surfaces.In this paper,a silane coupling agent capable of connecting inorganic materials and reacting with organic materials is selected,and an auxiliary ligand 1,10-phenanthroline is introduced on the basis of rare earth binary complexes to improve energy transfer efficiency and better sensitivity.The Eu3+ternary complexes of silane modified o-phthaloyl chloride/1,10-phenanthroline have the advantages of strong fluorescence and stable chemical properties.At the same time,by investigating the influence of preparation conditions on the fluorescence emission intensity of europium ternary complex at 619 nm,the preparation time,preparation temperature,Eu3+ion concentration and the ratio of Eu3+ion to modified ligand were changed.Finally,the silane modified Eu3+teriary complex was hydrolyzed under acidic conditions to obtain-OH by using the properties of silane coupling agent.The chemical bonds were made with-OH on the surface of poplar wood and cotton respectively to prepare the luminescent wood and cotton.The results are as follows:The optimized reaction conditions of silane modified o-phthaloyl chloride/1,10-phenanthroline/Eu3+ternary complex was obtained by controlled variable method.The results showed that a high reaction temperature of 71°C was beneficial in obtaining stronger fluorescent wood;a reaction time of 8 h exerted a significant influence on fluorescent wood when the reactant concentration of the sample was 0.03 mol/L;The ratio of silane modified ligand/1,10-phenanthroline/Eu3+ complexes was 1:6:1 by fluorescence spectrum.The optimized reaction conditions of fluorescent wood with Eu(?)ternary complexes were as follows:the results showed that a high reaction temperature of 75? was beneficial in obtaining stronger fluorescent wood;a reaction time of 8 h exerted a significant influence on fluorescent wood when the reactant concentration of the sample was 0.03 mol/L.The optimized reaction conditions of fluorescent cotton with Eu(?)ternary complexes were discussed:when the reaction temperature of the complex is 60?,the reaction time with cotton is 5 h,the reaction temperature with cotton is 80?,and the drying temperature is not more than 80?,the modified cotton has the highest fluorescence emission intensity.The modified ligand,the modified Eu3+ temary complex and the structural composition of the modified wood and cotton were obtained by infrared spectroscopy.By fluorescence spectroscopy,the 5D2-7F?transition of Eu3+at 619 nm is enhanced,and the silane modified Eu3+complex modified wood/cotton can emit red fluorescence under UV light.