167. Amorphous carbon
167. Amorphous carbon
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167. 无定形碳
DOI：
10.1039/jr9520000923
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发表时间：
1952
期刊：
影响因子：
--
通讯作者：
T. D. Smith
中科院分区：
文献类型：
--
作者：
T. D. Smith
通过有机化合物碳化制备的碳已通过 X 射线衍射和气体吸附进行了检查。有机分子中氧的存在深刻地影响了所得炭的晶体学特征。这些炭的表面积变化很大：非常大的面积可能是由于存在高度多孔的三维交联结构；当材料在熔融状态下分解时，会出现小区域。有人建议（Riley，Quart。Reviews，1947，I，59）无定形碳由两种类型的结构组成，即（1）乱层、层状、类石墨结构，和（2）无序的三维交联结构。后者被描述为邻四亚苯基残基的三维重复。这一观点的证据来自对由各种有机物质制备的大量无定形碳的详细 X 射线检查（Blayden、Gibson 和 Riley，“Ultra-Fine Structure of Coals and Cokes”，BCURA，London，1947，178；J. Inst. Fael，1945；War Time Bulletin，117；Gibson、Holohan 和 Riley，J.， 1946, 456）。检查方法包括测量衍射带的半峰宽度并根据这些宽度计算平均的、假设的圆柱形微晶的尺寸。因此可以随着碳化温度的升高来跟踪微晶的生长。微晶的平均高度（c 尺寸）是通过琼斯公式 p= l-Oh/L, cos 8 由 002 衍射晕的校正半峰宽度计算得出；平均直径（a 尺寸）由 10 个交叉晶格衍射晕的半峰宽度通过 Warren 公式计算得出
Carbons, prepared by carbonisation of organic compounds, have been examined by X-ray diffraction and gas adsorption. The presence of oxygen in the organic molecule profoundly affects the crystallographic character of the resultant chars. Surface areas of these chars vary appreciably: very large areas may be due to the presence of a highly porous threedimensional cross-linked structure; small areas occur when the material decomposes in the fused state.IT has been suggested (Riley, Quart. Reviews, 1947, I, 59) that amorphous carbons are built up of two types of structure, viz.,(1) a turbostratic, lamellar, graphite-like structure, and (2) a disordered, three-dimensional cross-linked structure. The latter has been described as a three-dimensional repetition of o-tetraphenylene residues. The evidence for this view has been assembled from detailed X-ray examination of a large number of amorphous carbons prepared from a variety of organic substances (Blayden, Gibson, and Riley,“Ultra-Fine Structure of Coals and Cokes,” BCURA, London, 1947, 178; J. Inst. Fael, 1945, War Time Bulletin, 117; Gibson, Holohan, and Riley, J., 1946, 456). The method of examination consists in measuring the half-peak widths of the diffraction bands and calculating from these the dimensions of the average, hypothetical, cylindrical crystallites. It is thus possible to follow the growth of the crystallites with increasing temperature of carbonisation. The average height (c dimension) of the crystallites is calculated from the corrected half-peak width of the 002 diffraction halo by means of Jones’s formula p= l-Oh/L, cos 8; the average diameter (a dimension) is calculated from the half-peak width of the 10 cross-lattice diffraction halo by Warren’s formula