Study of carbon nano structured materials including activated carbon by using electron microscopy and simulation

在这项研究中，碳材料的纳米结构，包括活性炭，其中包含超微孔的尺寸在0.7 nm以下，分析了高分辨率透射电子显微镜（HRTEM），利用高分辨透射电子显微镜（HRTEM）对不同离焦量（Δfs）下的非晶碳膜进行了观察为了确定考虑阻尼特性的高分辨透射电子显微镜物镜透镜的相衬传递函数，以及传递函数的仿真。通过二维快速傅里叶变换（2D-FFT）获得的非晶碳膜的HRTEM图像的功率谱与模拟数据进行了比较。通过对高分辨透射电子显微镜图像进行二维快速傅里叶变换（2D-FFT）得到的碳材料的功率谱在中心点附近进行积分，可以分析出碳材料的结构。将该方法应用于聚苯基炭、沥青基炭、纳米碳纤维的分析，并将其应用于碳分子筛等活性炭，与气体吸附法进行了比较。含超氧阴离子的碳分子筛不能吸附N_2和Ar，但在高压下可以吸附CO_2。将通过HRTEM和图像分析方法获得的孔径分布与气体吸附的结果进行比较。在高分辨观测中，高分辨透射电子显微镜的像取决于物镜透镜的传递函数。传递函数对于精确观察无定形结构材料如活性炭是重要的。高分辨透射电镜结合图像分析被证明是有用的结构分析的ultrasonic和预期是一个独立的技术，用于确认气体吸附的有用性。通过本研究可以改进非晶类碳的分析方法。

In this study, the nano structure of carbon materials including activated carbons which contain ultra micro pores of under 0.7 nm in the size was analyzed by high resolution transmission electron microscopy(HRTEM), simulation and image processing.Amorphous carbon films are observed by HRTEM on different defocus values (Δfs) in order to determine the phase contrast transfer function of objective lens of the HRTEM with consideration with damping property as well as simulation of the transfer function. Power spectra of the HRTEM images of the amorphous carbon film obtained by 2 dimensional fast Fourier transform (2D-FFT) were compared to the simulation data. The structure of carbon materials can be known to be analyzed by integration their power spectra around the center point obtained by 2D-FFT of the HRTEM image. This method was applied to analyzing polypharaphenylene based carbons, pitch based carbons, and carbon nanofibers.The analysis method was also applied to a carbon molecular sieve and other activated carbons, and compared to gas adsorption. The carbon molecular sieve which contains ultramicropore could not adsorb N_2 or Ar but can CO_2 with high-pressure. Pore size distribution obtained by the HRTEM and image analysis method was compared to results of the gas adsorption. The HRTEM image depends on the transfer function of objective lens of the HRTEM in high-resolution observation. The transfer function is important for exact observation of amorphous structured materials such as activated carbons. The HRTEM combined with image analysis was shown to be useful for structural analysis of ultramicropore and was expected to be an independent technique for confirmation of gas adsorption usefulness. The analysis method of amorphous like carbons can be improved through this research.