Abstract

The degree of crystallinity of carbon fibers (CFs) of different manufacturers has been determined by means of the Raman scattering method. A gradient “core–shell” model for the CF structure has been suggested. The element composition of CFs has been determined by means of the X-ray electron probe analysis. It has been established that the CF includes oxygen-containing groups, the concentration of which varies from 2 to 4 wt %. A fibrillar structure of the CF shell has been identified via the methods of atomic force probe microscopy and transmission electron microscopy. Longitudinal and transverse sizes of fibrils have been determined. Using the method of low-temperature nitrogen adsorption, the specific surface area, porosity, and pore sizes of CFs have been determined. Isotherms of water vapor sorption by CF within the moisture range from 10 to 95 wt % have been obtained. It has been demonstrated that, for all the studied samples, the sorption isotherms can be approximated using the Dubinin–Radushkevich equation. The sorption capacity of water vapor by CFs has appeared to significantly exceed that of nitrogen, which was associated with the presence of oxygen-containing functional groups.

中文翻译：

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碳纤维吸水

摘要

不同制造商的碳纤维（CFs）的结晶度已通过拉曼散射法确定。已经提出了CF结构的梯度“核-壳”模型。CF的元素组成已通过X射线电子探针分析确定。已经确定，CF包括含氧基团，其浓度为2-4重量％。CF壳的原纤维结构已经通过原子力探针显微镜和透射电子显微镜的方法进行了鉴定。已经确定了原纤维的纵向和横向尺寸。使用低温氮吸附的方法，确定了CF的比表面积，孔隙率和孔径。已获得水分在10至95 wt％范围内被CF吸收的水蒸气的等温线。已经证明，对于所有研究的样品，可以使用Dubinin–Radushkevich方程来近似吸附等温线。CFs对水蒸气的吸附能力似乎大大超过了氮，这与含氧官能团的存在有关。