类玻璃碳材料的EELS分析

The Structure of a Glass-Like Carbon Characterized by Electron Energy Loss Spectroscopy

探讨以酚醛树脂为前驱物的类玻璃碳,在不同温度炭化处理过程中的微孔变化情况,利用透射电子显微镜中的能量损失谱(EELS)技术,观察其显微结构与化学结构的变化。高分辨电镜观察发现,材料呈现微晶石墨碳层围绕微小孔洞结构排列的无定形结构,孔洞的形成主要是由小分子气化过程中产生的。由EELS图谱中的CK-edge分别对应于1s电子跃迁到π~*和σ~*反键轨道的两个特征峰,可计算得到C原子化学键SP^2杂化程度随炭化温度条件的不同有可观察到的比较明显的变化。

Phenolic resins heated at different temperatures and activated under different conditions were analysised in terms of phase structure and chemical structure using a high resolution transmission electron microscopy equipped with a electron energy loss spectrometer （EELS）. It is shown that materials appear to be amorphous with many micro-pores surrounded by crystalline graphite layers; the formation of the pore is due to the gas evolution reaction. Using the intensities of peaks in EELS CK-ionization edge which arise from transition of an atomic ls electron to the ~ and antibonding band-like states, the percentage of sp^2-bonded carbon have been analyzed and the results reveal notable differences with carbonization temperature