单壁碳纳米管/（苯胺-氧乙烯-苯胺）嵌段共聚物聚集体的微结构调控及热电性能研究

By taking advantage of the temperature difference between body and its surrounding, thermoelectric materials are fabricated readily to power the wearable electronics. Due to the disadvantages of inorganic-based thermoelectric materials such as high cost and toxicity of heavy metal, organic polymers demonstrate obvious advantages such as low cost, nontoxicity of heavy metal, easy to mold, and flexibility. However, the low heat-electricity conversion efficiency and the low stability of n-type structure are challenging the application of organic polymers as thermoelectric materials. The project is proposed to prepare single-walled carbon nanotubes/(aniline-polyoxylene-aniline) triblock copolymers congeries by self-assembling. The significant features of this design lie in: 1) The conductivity and Seebeck coefficient can be improved simultaneously because of the ordered microstructures of congeries formed by tuning the interaction between block copolymers and carbon nanotubes in solvent. 2) The interaction between polyoxyethylene and single-walled carbon nanotubes ascertains the n-type stability of the congeries; 3) The thermal conductivity of congeries will be reduced or kept because of the phonon scattering effect caused by the single-walled carbon nanotubes; 4) The low molecular weight of aniline oligomers and high solubility of polyoxyethylene achieve the solubility and the processability of the materials. These features guaranteed the high thermoelectric conversion efficiency and high flexibility. The preparation and thermoelectric properties of congeries provide theoretical and experimental basis for the development of high performance organic thermoelectric materials.

利用人体体温与环境温差发电，热电材料能为可穿戴电子器件供电。无机热电材料存在制备工艺复杂、成本高、重金属毒性等问题。有机高分子具有质轻、低成本、无金属毒性、柔性好、易加工成各种形态等优点，特别适合于可穿戴设备，但存在热电转换效率低、n-型不稳定等问题。本项目采用自组装的方法制备单壁碳纳米管/（苯胺-氧乙烯-苯胺）嵌段共聚物聚集体。优势体现在：通过调控嵌段共聚物与碳纳米管在溶剂中的相互作用，形成有序微结构，显著提高聚集体的电导率与Seebeck系数；利用氧乙烯链段与碳纳米管的相互作用，维持聚集体的n-型稳定性；碳纳米管在基体中能增强嵌段共聚物的界面声子散射，降低或维持嵌段共聚物的低导热系数；寡聚体以及聚氧乙烯链段的高溶解性，能提高聚集体的可溶解加工性。通过这些机制，实现聚集体的高热电转换效率及优良的加工性与柔性。聚集体的制备与热电性能研究为高性能高分子热电材料的发展提供理论依据和实验基础。

利用人体体温与环境温差发电，热电材料能为可穿戴电子器件供电。无机热电材料存在制备工艺复杂、成本高、重金属毒性等问题。有机高分子具有质轻、低成本、无金属毒性、柔性好、易加工成各种形态等优点，特别适合于可穿戴设备，但存在热电转换效率不高、n型结构不稳定等问题。本项目制备了（苯胺-氧乙烯-苯胺）嵌段寡聚物，然后与改性单壁碳纳米管复合，利用氧乙烯原位提供氧孤对电子，实现了材料稳定的n型结构；同时利用单壁碳纳米管与苯胺寡聚物的π-π共轭作用，促进苯胺寡聚物的紧密堆积与有序排列，显著提高材料的电导率与Seebeck系数；利用寡聚物的低分子量设计以及聚氧乙烯链段的高溶解性，提高材料的可溶解加工性。通过这些机制，实现了材料较高的热电转换效率及优良的加工性与柔性。但是不同的复合方式对电导率和Seebeck系数及热导率的影响不同。对于去耦机理及多重界面结构与热导率的关系，有待于进一步研究。通过本项目的研究为开发高性能n型热电材料及其在可穿戴热电设备中的应用提供一定的指导。受基金资助已发表SCI论文9篇，EI论文1篇，申请发明专利9项，授权4项，国际/国内学术会议口头报告3次，培养研究生6名。