基于低温热释放的烷基接枝相变偶氮苯材料

通过Mills法合成了两种不同取代基的烷基接枝相变偶氮苯——4-正戊基偶氮苯(Azo5)和2′-甲基-4-正戊基偶氮苯(AzoM5). 通过核磁共振氢谱和傅里叶变换红外光谱表征了Azo5和AzoM5的化学结构, 利用紫外-可见光谱、 示差扫描量热仪和红外热像仪分析了材料的异构化性能、 循环稳定性、 储热和放热性能, 并测试了?10 ℃环境下的热量释放能力. 结果表明, Azo5和AzoM5由于分子间作用力低, 呈现出低熔点、 快速异构化的特点, 并且由于低温下的光致相变行为, 能量密度显著提高, 分别达到216和218 J/g. 红外热成像仪观测结果表明, 在可见光照射下, Azo5在低温环境(?10 ℃)下可以实现6 ℃的温度提升.

Alkane Grafted Phase Change Azobenzene Materials Based on Low Temperature Heat Release

Alkyl-grafted phase change azobenzenes， 4-pentyl-azobenzene（Azo5） and 2'-methyl-4-n-pentylazobenzene（AzoM5）， with two different substituents were synthesized by the Mills method. The chemical structures of Azo5 and AzoM5 were characterized by nuclear magnetic resonance hydrogen spectroscopy and Fourier transform infrared spectroscopy. The isomerization performance， cycling stability， thermal storage， exothermic properties and the ability to release heat at ?10 ℃ of the materials were analyzed by ultraviolet-visible spectroscopy， differential scanning calorimetry and infrared thermography. The results show that Azo5 and AzoM5 exhibit low melting point and rapid isomerization transformation due to the low intermolecular force. And due to the photo-induced phase change at low temperature， the energy density increases significantly， reaching 216 and 218 J/g， respectively. Infrared thermography shows that Azo5 can achieve a temperature increase of 6 ℃ at low temperatures（-10 ℃） under visible light irradiation.