H3PO4溶液中碳纤维表面电化学改性机理研究

以H3PO4溶液为电解液对碳纤维进行电化学改性处理,通过循环伏安测试,XPS、SEM和XRD分析探讨了H3PO4溶液体系中碳纤维表面电化学改性机理。结果表明:在改性处理初期,纤维表面已有电活性物质发生电化学反应产生新的活性碳原子,此后伴随着水的电解析氧反应纤维表面进一步受到氧化和刻蚀,表面氧元素含量增加,而且各种含氧官能团含量随着改性处理得进行不断变化,其中羧基和酸酐含量明显增加。纤维表面粗糙度增加,沟槽加深加宽,但其本体结构并没有改变,只是表面层微晶尺寸有所减小,晶面间距有所增大。

Study on the mechanisms of electrochemical surface treatment of carbon fibers in H3 PO4 solution

The carbon fibers were electrochemical treated in H_3PO_4 solution. The treatment mechanisms were investigated using cyclic voltammetry, XPS, SEM and XRD measurements. The results indicated that the electro active substances on the fibers were reacted to produce new active carbon atom under the polarization current in initial stage, then the fibers were oxidized and etched more and more greatly under the couple action of polarization current and the electrolyzation of water. The content of oxygen element on the fiber surface were increased. The concentration of different functional groups which contained oxygen element were changed continuously during the surface treatment period. The carboxyl group and acid anhydride were increased with the treatment time extending. The surface morphology of carbon fibers was rougher and the grooves on the fiber surface were wider and deeper after treatment. Whereas the bulk structure of the fiber was not changed during treatment, the structure of micro crystallite on the fiber surface was changed slightly.