通过共价有机框架的可逆异构检测湿度
Samik Jhulki1, Austin M Evans, Xue-Li Hao1
1School of Chemistry and Biochemistry and Center for Organic Photonics and Electronics , Georgia Institute of Technology , Atlanta , Georgia 30332-0400 , United States.
Journal of the American Chemical Society
|January 3, 2020
概括
具有二胺醇部分的共价有机框架 (COF) 呈现出快速,可逆的颜色变化,以应对水等极性溶剂. 这种色度检测能力由分体化驱动,为湿度检测提供了一个稳定的平台.
科学领域:
- 材料科学
- 超分子化学
- 化学传感器
背景情况:
- 共价有机框架 (COF) 是具有可调的晶体多孔聚合物.
- 开发敏感和选择性的化学传感器仍然是材料科学的关键挑战.
- 了解分子结构与光学特性之间的关系对于传感器设计至关重要.
研究的目的:
- 调查含有二胺醇部分的特定共价有机框架 (COF) 的变色特性.
- 探索观察到的颜色变化及其可逆性的机制.
- 评估这种COF作为溶剂和湿度的色度传感器的潜力.
主要方法:
- 用2,5-二胺替代的1,4-二氧 (二胺) 单元合成共价有机框架 (COF).
- 频谱分析 (UV-Vis吸收) 用于监测各种溶剂和溶剂蒸汽的颜色变化.
- 密度函数理论 (DFT) 和时间依赖的DFT计算,以阐明电子结构和分体化机制.
- 使用面向薄膜COF的色度湿度传感器的制造和测试.
主要成果:
- 在接触极性溶剂,特别是水时,COF呈现出快速,被动和可逆的颜色变化.
- 在极性溶剂的存在下出现了新的可见吸收带,表明可逆转换.
- DFT计算显示,二胺醇和二胺醇/cis-ketoenamine形式之间的溶剂诱导的分体化是导致光学变化的原因.
- 与diminol相比,imininol/cis-ketoenamine共聚体具有较长的波长吸收和显著的电荷转移特性.
- 一个基于COF的湿度传感器表现出对水蒸气的快速反应,并保持了几个月的稳定性.
结论:
- 在COF中因自动化引起的电子结构变化可以有效地用于传感应用.
- 报告的COF为开发快速,可逆和长期稳定的色度传感器提供了一个有前途的平台,特别是用于湿度检测.
- 这种简单可见的颜色变化机制突显了在功能材料中利用动态共价化学的潜力.
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