Azo-compounds molecules and phase change materials offer potential applications for sustainable energy systems through the storage and controllable release photochemical and phase change energy. Developing novel and highly efficient Azo-based solar thermal fuels (STFs) for photothermal energy storage and synergistic cooperation with organic phase change materials present significant challenges. Herein, three types of (ortho-, meta-, and para-) azopyridine polymers hinged with flexible alkyl chain are synthesized, in which meta-azopyridine polymer exhibits striking photothermal storage capacity of 430 J/g, providing a feasibility solution for developing high energy density Azo-based STFs. Furthermore, a stable two-phase hybrid system was innovatively constructed by combining the meta-azopyridine polymer with organic phase change materials leveraging hydrogen bonds and van der Waals interactions to collectively harness phase change energy and photothermal energy. The organic phase change material not only supplies additional phase change latent heat but also serves as a solvent, offering abundant free volume for the photo-induced isomerization of the azopyridine chromophores, which successfully circumvents the low charging efficiency in the condensed state and reliance on solvent-assisted charging in traditional Azo-based STFs. This study demonstrates the energy distribution and utilization for household consumers and the photothermal-assisted insulation strategy, achieving more extensive potential implementation for STFs.

中文翻译：

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偶氮吡啶聚合物在有机相变材料中的高能量密度光热储存和控释


偶氮化合物分子和相变材料通过储存和可控释放光化学和相变能为可持续能源系统提供了潜在的应用。开发用于光热能存储的新型高效 Azo 基太阳能热燃料 （STF） 以及与有机相变材料的协同合作提出了重大挑战。本文合成了三种类型（邻位、间位和对位）偶氮吡啶聚合物，这些聚合物与柔性烷基链连接，其中间偶氮吡啶聚合物表现出惊人的 430 J/g 光热存储容量，为开发高能量密度偶氮基 STF 提供了可行的解决方案。此外，通过将间偶氮吡啶聚合物与有机相变材料相结合，利用氢键和范德华相互作用共同利用相变能和光热能，创新性地构建了稳定的两相混合系统。有机相变材料不仅提供额外的相变潜热，还可用作溶剂，为偶氮吡啶发色团的光诱导异构化提供了丰富的自由体积，成功地规避了传统偶氮基 STF 中冷凝态下的低充电效率和对溶剂辅助充电的依赖。本研究展示了家庭消费者的能源分配和利用以及光热辅助绝缘策略，实现了 STF 更广泛的潜在实施。