基于自组装量子点的应力应变监测

发布时间：2018-04-14 05:27

  本文选题：量子点 + 温度稳定性　； 参考：《华东理工大学》2017年硕士论文

【摘要】：设备结构的应力应变的实时精确监测是保证其安全可靠运行的关键。量子点在受力状态下存在明显荧光响应。而量子点的荧光不稳定性和在基体材料中分布的无序性限制了其在结构健康监测领域的发展。本文基于核壳CdSe/ZnS绿色荧光量子点,研究了量子点荧光性能温度稳定性并初步解析了机理。针对量子点的无序化分布,开发了基于蒸发诱导工艺的量子点条形和环形自组装。开展了基于自组装量子点的应力应变监测。论文主要获得以下结果:(1)当温度低于200℃时,量子点的荧光强度与温度呈现负相关的变化关系,荧光波长与温度呈现正相关的变化关系,在多次的温度循环过程中,量子点荧光性能存在可恢复性。高温下,量子点结构的不可逆性导致了量子点荧光的淬灭。(2)通过蒸发自组装的工艺可实现量子点的条形和环形自组装,量子点的荧光强度(断面面积)和波长(相邻同心环间距离)随距离的增加而线性增强和增大。通过钢球粒径大小、复合薄膜厚度和量子点浓度的改变可实现环形自组装荧光图案结构的调控。溶剂的挥发会导致薄膜和自组装图案形成裂纹,量子点浓度越高,复合薄膜越厚,裂纹的宽度越大。(3)基于蒸发诱导的工艺实现在抛光金属表面的量子点环形自组装,拉伸过程中,波长随拉力的增大而线性增加,波长相对于力的斜率随角度的增加而减小。
[Abstract]:The real-time and accurate monitoring of the stress and strain of the equipment structure is the key to ensure its safe and reliable operation.The quantum dots have obvious fluorescence response.The fluorescence instability of QDs and the disordered distribution of QDs in matrix materials limit the development of QDs in the field of structural health monitoring.Based on core-shell CdSe/ZnS green fluorescent quantum dots, the temperature stability of fluorescence properties of quantum dots was studied and the mechanism was preliminarily analyzed.For the disordered distribution of quantum dots, self-assembly of quantum dots based on evaporation induction process was developed.Stress and strain monitoring based on self-assembled quantum dots is carried out.The main results of this paper are as follows: (1) when the temperature is below 200 鈩，

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