温度对低功率上升转换的影响在性聚合物混合物中
Tanya N Singh-Rachford1, Joseph Lott, Christoph Weder
1Department of Chemistry and Center for Photochemical Sciences, Bowling Green State University, Bowling Green, Ohio, 43403, USA.
Journal of the American Chemical Society
|August 5, 2009
概括
研究了聚合物宿主中温度依赖的上转换. 在玻璃过渡温度 (T(g)) 以上的加热,可以通过三倍三倍灭绝 (TTA) 发出蓝光,直到发生热降解才可逆.
科学领域:
- 光化学和材料科学 材料科学
- 研究聚合物矩阵中的光物理过程.
背景情况:
- 上转换发光允许从低能量的光子产生更高能量的光子.
- 帕拉 (II) 八甲基 (PdOEP) 作为三重敏感剂,9,10-二甲基 (DPA) 作为三重接受剂/消灭剂.
- 具有低玻璃过渡温度 (T(g)) 的聚合物宿主对于对温度敏感的光物理行为至关重要.
研究的目的:
- 为了研究PdOEP/DPA染料尾酒在各种低T (g) 聚合物宿主中的温度依赖的上转换特性.
- 了解敏感三倍三倍灭绝 (TTA) 的机制及其与聚合物矩阵动态的关系.
- 为了确定上转换过程的热稳定性和可逆性.
主要方法:
- 利用PdOEP在544nm的选择性激发来诱导DPA的反斯托克斯蓝色辐射.
- 检查向上转换的光强度与落灯功率 (二次关系) 的依赖性.
- 在各种温度范围内监测上升转换效率,包括在EO-EPI,Texin和Tecoflex等聚合物宿主的T (g) 以下和以上.
主要成果:
- 上转换在T (g) 下被抑制,但在加热到室温时清晰可见.
- 上转换的排放强度随温度增加,并且在低于400K的加热-冷却周期下可逆.
- 在400K以上,不可逆转的材料故障阻止了进一步的升级.
- 在Tecoflex EG-80A中光衰变分析显示,系统异质性与温度增加 (KWWβ值较低).
结论:
- 聚合物主体的T (g) 通过TTA对温度依赖的上升转换进行了关键控制.
- 上转换过程的可逆性为温度敏感的光子材料提供了潜力.
- 热稳定性限制了操作温度范围,降解发生在400K以上.
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