Semi-quantitative analysis of the structural evolution of mesophase pitch-based carbon foams by Raman and FTIR spectroscopy

Raman和FTIR光谱半定量分析中间相沥青基泡沫炭的结构演变行为

Graphitized carbon foams(GFms)were prepared using mesophase pitch(MP)as a raw material by foaming(450℃),pre-oxidation(320℃),carbonization(1000℃)and graphitization(2800℃).The differences in structure and properties of GFms prepared from different MP precursors pretreated by ball milling or liquid phase extraction were investigated and compared,and semi-quantitative calculations were conducted on the Raman and FTIR spectra of samples at each preparation stage.Semi-quantitat-ive spectroscopic analysis provided detailed information on the structure and chemical composition changes of the MP and GFm de-rived from it.Combined with microscopic observations,the change from precursor to GFm was analyzed.The results showed that ball milling concentrated the distribution of aromatic molecules in the pitch,which contributed to uniform foaming to give a GFm with a uniform pore distribution and good properties.Liquid phase extraction helped remove light components while retaining large aromatics to form graphitic planes with the largest average size during post-treatment to produce a GFm with the highest degree of graphitization and the fewest open pores,giving the best compression resistance(2.47 MPa),the highest thermal conductivity(64.47 W/(m·K))and the lowest electrical resistance(13.02μΩ·m).Characterization combining semi-quantitative spectroscopic ana-lysis with microscopic observations allowed us to control the preparation of the MP-derived GFms.

以中间相沥青(MP)为原料,经450℃发泡、320℃预氧化、1000℃炭化和2800℃石墨化工艺制备了石墨化泡沫炭(GFm)。同时研究并比较了MP前驱体经球磨或液相萃取预处理后制备的GFm在结构和性能上的差异,对每个制备阶段样品的拉曼光谱和红外光谱图进行了半定量计算分析。在此基础上,结合半定量光谱分析提供的泡沫炭结构和化学成分的详细信息及其显微观察特征,深入分析了制备过程中由MP到GFm的结构演变行为。结果表明:球磨可以使MP中芳烃组分分布趋于集中,有助于均匀发泡,从而获得孔径均匀、综合性能较优的GFm。液相萃取有助于去除MP中的轻组分,同时保留大的芳烃分子,在后处理过程中形成具有最大平均尺寸的碳质微晶平面,从而获得石墨化程度最高、开孔最少的GFm,并呈现出最佳的抗压性能(2.47 MPa)、最高的热导率(64.47 W/(m·K))和最低的电阻(13.02μΩ·m)。因此,本文建立的半定量光谱分析与显微观察相结合的表征策略,为中间相沥青基泡沫炭的结构演变分析及其可控制备提供了可靠的理论知识。