The self assembly at carbon fiber/epoxy interface in composites

In order to gain a controlled interface between carbon fiber and epoxy matrix at molecular level, a new method based on the molecular self-assembly was proposed for the carbon fiber surface modification. The surface-enhanced Raman scattering spectroscopy (SERS) analysis verified that a series of hydroxyl-substituted alkanethiols with different alkyl chain lengths chemisorbed onto the Ag-plated carbon fibers and formed a stand-up phase. The microbond testing results showed that the interfacial bonding strengths of modified carbon fiber/epoxy composites were improved. The relationship between alkyl chain length and interfacial properties was revealed.