煤焦油基碳薄膜的可控制备及其导电性能调控机制研究

The outstanding electrical, optical, thermal and mechanical properties of carbon films make them potentially useful for functional devices. Based on the high degree of graphitization and high conductivity of functional carbon materials synthesized from coal tar pitch, it is simple and scalable to prepare carbon films with excellent performance on the substrate by using coal tar with low cost and rich in condensed ring structure. The project aims at the controllable preparation of coal tar-based carbon films and the regulation of electrical conductivity. The key factors controlling the structure and properties of carbon films were revealed by studying the relationship between the composition and structure of the tar and the heat treatment conditions and the morphology, structure and electrical conductivity of the carbon films. The composition and structure of coal tar, the degree of graphitization of carbon film and the structure of carbon film were modified by catalytic polymerization, catalytic graphitization and composite nanowire metal lines, respectively. The relationship between the morphology, structure and electrical conductivity of the carbon thin film was investigated to reveal the regulation mechanism of the morphology, structure and electrical conductivity of the carbon thin film. Furthermore, based on the research on the application properties of coal tar-based carbon films in Joule heating devices, the structure of the carbon films used in the heating devices and the key control factors in the preparation process are revealed. The project not only provides theoretical and technical support for controlled preparation of functionalized coal tar-based carbon film and development of application, but also realizes the high value-added utilization of coal tar.

碳薄膜优异的电学、光学、热学和机械性能使得其在功能器件领域应用潜力巨大。基于焦油沥青为原料合成的功能碳材料石墨化程度高和电导率高等特性，利用价廉富含稠环结构的煤焦油在基底上直接制备性能优良的碳薄膜工艺简单可规模化。项目以煤焦油基碳薄膜的可控制备和导电性能调控为目标，通过研究焦油组成和结构及热处理条件与所制碳薄膜形貌、结构和导电性能之间关系，揭示控制碳薄膜结构和性能的关键因素；利用催化聚合、催化石墨化和复合纳米金属线分别对煤焦油组成和结构、碳薄膜的石墨化程度和碳薄膜结构进行调变，研究碳薄膜形貌、结构和导电性之间关系，揭示碳薄膜形貌、结构和导电性的调控机制。进而基于煤焦油基碳薄膜在焦耳电热器件应用研究，揭示碳薄膜在电热器件方面应用的结构和制备过程关键控制因素。本项目的研究不仅为功能化煤焦油基碳薄膜可控制备及应用技术开发提供理论与技术支持，而且可以实现煤焦油的高附加值利用。

碳薄膜电学、光学、热学和机械性能优异使得其在功能器件领域应用潜力巨大。利用价廉富含稠环结构的煤焦油直接制备石墨化程度高和电导率高等的碳薄膜不仅可实现碳薄规模化制备，而且可实现煤焦油高附加值利用。项目以煤焦油碳薄膜的可控制备和导电性能调控为目标, 采用高温煤焦油为碳源，石英玻璃片为反应基底,采用负压化学气相沉积法成功制备了煤焦油基碳膜材料，探究了制备工艺参数对碳膜结构和性能的影响，揭示了煤焦油基碳膜结构和其导电性能、电热性能间的关系。发现延长碳化时间、提高碳化温度和提高煤焦油添加量可有效降低碳膜的电阻率和方块电阻。煤焦油基碳膜的载流子浓度较大，均在1021-1022/cm 3 范围内；而迁移率较小(小于 1cm2/Vs)。探究了煤焦油中的不同组分对碳膜结构和性能的影响，发现萘基碳膜的导电性能和电热性质最好，其电阻率和方块电阻分别为6.4×10-4Ohm·cm 和43.4Ohm/sq, 30 V下的最大发热温度超过300oC。研究了煤焦油中的杂原子化合物对碳膜的制备及性能导电性能和电热性能的影响，发现杂原子的存在会增加碳膜的载流子浓度，但同时会降低碳膜的载流子迁移率。以煤沥青、蒽油、萘油、洗油、焦油为碳源，研究了前驱体的选择对碳膜的附着力、防腐性能的影响，发现以煤沥青为碳源所制备碳材料的缺陷度小，石墨化程度低，导电性高，电热性能优异，沥青基碳膜在5V、10V和15V电压下的发热温度分别达到37oC、66oC和95oC，聚偏二氟乙烯为优异的粘结剂。研究了石墨烯、多壁碳纳米管作为结构导向剂、杂原子诱导效应以及金属的催化对碳材料结构和电热性能的影响，通过调控碳材料的形貌与结构制备出导电性能和电热性能可控的碳基电热复合材料，并探究了碳材料的形貌与结构对碳膜结构和电热性能的影响规律，揭示了煤沥青基碳膜的导电性能和电热性能的调控机制。发现石墨烯掺杂和多壁碳纳米管掺杂、二茂铁和铜纳米线导致碳材料的碳层厚度减小，晶格排列有序度升高，晶格间距减小，电热性能提升。