具有光热存储功能的纳米纤维素基偶氮苯复合物的制备及应用

Nanocellulose-Based Azobenzene Derivative with Photothermal Storage Function

为解决小分子偶氮苯(AZO)能量密度低、储能时间短等问题,以溴化纤维素纳米纤(CNF-Br)为模板,与含柔性长链的偶氮苯衍生物经原子转移自由基聚合(ATRP)后形成一种具有长支链梳型的纤维素基偶氮苯复合物(CNFAZO)。利用红外光谱、核磁共振和X射线衍射分析对所得的偶氮苯衍生物(AZOC_(6)OH和AZOC_(6)MA)和CNF-AZO复合物的结构进行表征。并利用紫外-可见光分光光度计和差示扫描量热法对CNF-AZO的光异构化和储能性能进行测试。结果表明,所得的CNF-AZO复合物对紫外光(365 nm)具有良好的响应性,且在黑暗条件下维持在高能顺式异构体的时间长达80 h。而在热刺激下,该复合物可由顺式异构体回复到反式异构体,并同时释放所存储的紫外光能,其能量密度可达44.6 kJ/kg。

In order to solve the problems of low energy density and short energy storage time for small molecule azobenzenes(AZO),CNF-Br was chosen as template and reacted with an azobenzene derivative containing flexible long chains by atom transfer radical polymerization(ATRP)to prepare a cellulose-based azobenzene(CNF-AZO)composite with a long-chain comb shape.The structures of the azobenzene derivatives(AZOC_(6)OH and AZOC_(6)MA)and CNF-AZO complex were characterized by FT-IR,1H-NMR and XRD.The photoisomerization and energy storage properties of CNF AZO were measured by UV-Vis spectrophotometer and differential scanning calorimetry.The resultant CNF-AZO composite exhibits light-response to ultraviolet light(365 nm),and maintains at high-energy state cis-isomer for 80 h in the dark.Under the stimulation of thermal,the complex returns from the cis-isomer to the trans-isomer while releasing the stored UV energy,and its energy density reaches 44.6 kJ/kg.