摘要
开发具有持久稳定室温磷光的弹性体材料是柔性电子学和光子学领域的一大挑战.本文报到了一种高度可拉伸、高机械强度且可持续发光的室温磷光共价有机框架弹性体(SPU-D230-UPy COF)材料.该材料由烷基链软段与含多重氢键硬段限域共价有机框架而组成,展现出高的机械性能和高弹性.在除去365 nm的激发后,具有明亮且持续的室温磷光发射特性(发光时间持续3.0 s).力学研究表明,其具备约33.5 MPa的强度、约188.26 MJ/m3的优异韧性以及约76.6 MPa的杨氏模量.同时该弹性体即使经历反复的机械变形也能保持优异的光学性能.本研究为发光弹性体在可穿戴设备、柔性显示器和防伪设备等方面的应用奠定了基础.
Abstract
Elastomer materials with long-lasting and stable room-temperature phosphorescence have great potential in the fields of flexible electronics and photonics.However,developing such materials remains a daunting challenge.Systems of small molecule doped polymers are limited by the tensile properties of the polymer matrix.Currently commonly used poly(methylmethacrylate)(PMMA)and poly(vinyl alcohol)(PVA)have poor tensile properties.However,the increased flexibility cannot provide rigid external conditions for phosphorescence emission.This trade-off parameter adjustment has always hindered its development.Here,we report a highly stretchable and mechanically strong sustainable luminescent room-temperature phosphorescent covalent organic framework elastomer(SPU-D230-UPy COF)material.The material is composed of an alkyl chain soft segment and a limited covalent organic framework containing multiple hydrogen bonding hard segments.This structural design of separated soft and hard segments provides the structural basis for high mechanical properties,high toughness,and phosphorescent emission.The soft segment structure can ensure its high stretchability,and the hard segment structure can provide high mechanical strength while also providing a rigid environment for phosphorescence emission.These prepared elastomers exhibit high mechanical properties and high elasticity,and exhibit bright and sustained luminescence after removal of 365 nm excitation(luminescence time lasts for 3.0 s).Mechanical studies show that the obtained material exhibits a strength of～33.5 MPa and excellent toughness of～188.26 MJ/m3,with a Young's modulus of～76.6 MPa.The material can easily lift heavy objects without breaking.Impressively,these elastomers maintain strong optical properties even under repeated mechanical deformation,an unprecedented property.These outstanding properties make these long-lasting luminescent elastomers ideal for potential applications in wearables,flexible displays,and anti-counterfeiting devices.This separate structural design of soft and hard segments effectively breaks the trade-off between structural flexibility and phosphorescence emission.It can not only improve the mechanical properties,flexibility and stretchability of the material,but also effectively maintain the phosphorescence emission,which will provide a new path for the development of stretchable elastomer phosphorescent emissive materials.
维普
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