Continuous method for grafting CNTs on the surface of carbon fibers based on cobalt catalyst assisted by thiourea

• Published in: Journal of materials science Vol. 54; no. 19; pp. 12498 - 12508
• Main Authors: Su, Shunsheng, Wang, Yanxiang, Qin, Jianjie, Wang, Chengguo, Yao, Zhiqiang, Lu, Ruijiao, Wang, Qifen
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.10.2019; Springer; Springer Nature B.V
• Subjects: Analysis; Carbon fibers; Carbon nanotubes; Catalysis; Catalysts; Catalytic activity; Characterization and Evaluation of Materials; Chemical Routes to Materials; Chemical vapor deposition; Chemistry and Materials Science; Classical Mechanics; Cobalt; Crystallography and Scattering Methods; Grafting; Graphitization; Materials Science; Mechanical properties; Methods; Microscopy; Morphology; Nanotubes; nitrates; Organic chemistry; Polymer Sciences; Raman spectroscopy; Scanning electron microscopy; Solid Mechanics; sulfur; Tensile strength; thiourea; Thioureas; Transmission electron microscopy; vapors; X-ray diffraction
• ISSN: 0022-2461; 1573-4803
• DOI: 10.1007/s10853-019-03827-8

This paper provides a continuous method for grafting carbon nanotubes (CNTs) on the surface of carbon fibers by chemical vapor deposition (CVD). The control of the morphology of CNTs/CFs can be achieved by adding thiourea to the cobalt nitrate precursor. The sulfur can increase the catalytic activity of the Co catalyst. Scanning electron microscopy reveals that a uniform layer of CNTs is grafted onto the surface of carbon fibers with the presence of thiourea. Through the single-filament tensile strength test, it can be found that the tensile strength of the fiber is increased by up to about 10% compared with the desized carbon fibers after the CVD process. And the reason for the enhancement is explored through X-ray diffraction. Raman spectroscopy reveals that the sample possesses the highest degree of graphitization at a thiourea concentration of 0.02 mol/L. It is found by high-resolution transmission electron microscopy that the growth mechanism of CNTs is tip growth mechanism, and the diameter of the CNTs is about 15 nm.