基于快速热释放功能的相变偶氮苯/织物复合材料

针对偶氮基光敏分子存在放热速率慢和温度难以控制的难点,在分子结构设计基础上,采用氧化偶合法制备了具有固-液相变功能的4,4′-对-二正己基偶氮苯(AZO-L6).由于分子间作用力较低,偶氮苯分子呈现低熔、快异构化的特点,在发生反-顺异构化转变时大幅降低分子的熔点.固-液相变过程实现了光热能和相变焓的存储,在结构回复时同时放出储存的能量(231.8 kJ/kg),并将相变偶氮苯应用于可穿戴聚合物复合织物中.结果显示储能后的相变偶氮苯分子在蓝光(440 nm)刺激下在60 s内可将材料温度提升0.8℃,获得了具有自加热功能的可穿戴复合织物,为探索多功能自保温可穿戴装置提供了研究思路.

Phase Change Azobenzene/Fabric Composite Material Based on Rapid Heat Release Function

Due to the instant conversion of traditional photothermal conversion,solar energy could be stored for a short time,which limits its utilization in solar energy storage.Using photosensitive molecules as photothermal conversion materials,solar energy is stored in chemical bond,which becomes a common solution in this field and an important part of photothermal conversion field.As a common photothermal conversion material with simple synthesis,low cost and not easy to degrade,azobenzene(azo)can change from trans-structure to cis-structure in the light of specific wavelength and store the light energy in the chemical bond.When return to trans-structure under external stimulation,cis-azo release energy in the form of heat energy,completing a light heat storage and release cycle.In view of the difficulties in the slow heat release rate and controlling the temperature of azo-based photosensitive molecules,based on the molecular structure design,4,4'-dihexylazobenzene(AZO-L6)with solidliquid phase change function was prepared by the oxidation coupling method.The successful preparation of AZOL6 was proved by relevant tests.Due to the low intermolecular force,the azo molecule is characterized by low melting point and fast isomerization,and when the trans to cis isomerization transition occurs,the melting point of the azo molecule greatly reduced.The process of solid-liquid phase changing realizes the storage of photothermal energy and phase change latent heat,and simultaneously releases the stored energy(231.8 kJ/kg)when returning to the cis-structure.We apply AZO-L6 to the wearable polymer composite fabric.It is proved that azo is fully filled into the fabric,and the isomerization of azo is hindered,while the recovery process is not affected.Under the stimulation of blue light(440 nm),the phase change azo molecule can make the material temperature go up 0.8°C within 60 s,and a wearable composite fabric with self-heating function is obtained,which provides research ideas for exploring multifunctional self-insulating wearable devices.