无机复合涂层对碳纤维性能的影响

Effect of inorganic composite coating on carbon fiber properties

采用溶胶-浸渍法在碳纤维表面制备了二氧化钛-二氧化硅复合涂层。考察了钛溶胶与硅溶胶体积比、浸渍方式、浸渍次数对涂层的影响。利用X射线衍射(XRD)、扫描电镜(SEM)和透射电镜(TEM)分析了涂层的相组成及形貌。通过静态等温氧化实验考察了复合涂层碳纤维的抗氧化性能。结果表明:钛溶胶与硅溶胶体积比为15∶1条件下采用真空超声浸渍3次,制备的复合涂层均匀、完整、致密,与碳纤维表面结合良好,涂层抗氧化性能好,涂层二氧化钛为锐钛矿型、二氧化硅为无定型。将复合涂层碳纤维在400℃连续氧化15 h,其质量损失率仅为5.91%。

SiO2-TiO2 composite coating was prepared on the surface of carbon fiber by sol-dipping method. The influence of titanium-silica ratio, dipping methods, and dipping times on the coating was investigated.The phase composition and morpho- logy of the prepared samples were characterized by X-ray diffraction （XRD）, scanning electronic microscopy （SEM）,and transmission electron microscopy （TEM）.The oxidation resistant properties of the carbon fibers with composite coating were studied by static isothermal oxidation experiment.Results showed under the optimum dipping conditions,such as dipping 3 times in vacuum and ultrasonic environment and volume ratio of titanium to sol of 15：1, the uniform and compact composite coating could be obtained.The composite coating banded well with the surface of carbon fiber and had a good oxidation resis- tance performance.Furthermore, the prepared layer was composed of anatase TiO2 and amorphous SiO2.The sample was con- tinuously oxidized at 400 ℃ for 15 h and its mass loss rate was only 5.91%.