Carbon fiber/epoxy composite property enhancement through incorporation of carbon nanotubes at the fiber–matrix interphase – Part I: The development of carbon nanotube coated carbon fibers and the evaluation of their adhesion

• Published in: Composites. Part A, Applied science and manufacturing Vol. 43; no. 9; pp. 1569 - 1577
• Main Authors: Kamae, Toshiya, Drzal, Lawrence T.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.09.2012; Elsevier
• Subjects: A. Carbon fiber; A. Nano-structures; A. Particle-reinforcement; adhesion; Applied sciences; B. Interface/interphase; carbon fibers; carbon nanotubes; coatings; Composites; epoxides; Exact sciences and technology; forces; Forms of application and semi-finished materials; interphase; Laminates; Polymer industry, paints, wood; polymers; shear strength; suspensions; Technology of polymers; testing; A. Nano-structures; A. Carbon fiber; B. Interface/interphase; A. Particle-reinforcement; Coating material; Interphase; Coated fiber; Epoxy resin; Carbon nanotubes; Mechanical properties; Shear strength; Polymer; Dispersion reinforced material; Mineral fiber; Adhesion; Composite material; Polyelectrolyte; Interface properties; Olefinimine polymer; Polyethylene imine; Carbon fiber
• ISSN: 1359-835X; 1878-5840
• DOI: 10.1016/j.compositesa.2012.02.016

A new method to realize the uniform coating of carbon nanotubes (CNTs) to carbon fibers (CFs) has been developed, which enables the scalable fabrication of CNT containing CF/epoxy composites. In this method, CNTs are treated by cationic polymers, then, the CNTs are coated to CFs by immersion into a CNT/water suspension. Good dispersion is achieved by repulsive force between positively charged CNTs and uniform coating of the CNTs is achieved by attractive forces between positively charged CNTs and negatively charged CFs. It is found that the use of specific cationic polymers including polyethyleneimine (PEI) results in stable CNT/water suspensions, and uniform coating of the CNTs. Single fiber fragmentation tests of the CF/epoxy composites were conducted to evaluate the strength of interface and interphase under shear loading. The results show that the combination of epoxy resin sizing and PEI treated CNT coating to CFs results in high interfacial shear strength.