Using molecular entanglement as a strategy to enhance carbon fiber-epoxy composite interfaces. (18th August 2020)

• Record Type: Journal Article
• Authors: Eyckens, Daniel J.; Demir, Baris; Randall, James D.; Gengenbach, Thomas R.; Servinis, Linden; Walsh, Tiffany R.; Henderson, Luke C.
• Is Part Of: Composites science and technology. Volume 196(2020)
• Publication Date: 2020-08-18
• Subjects: Composite materials -- Periodicals; Composite materials; Fibrous composites; Periodicals; 620.118
• DOI: 10.1016/j.compscitech.2020.108225
• Languages: English
• ISSNs: 0266-3538

Abstract

Abstract: The tethering of an amphiphilic molecule to the surface of carbon fiber resulted in significant (+283%) improvements in interfacial shear strength. Molecular dynamics simulations revealed that lateral association of hydrophobic sections lead to a 'hooked' conformation through which polymer chains become entangled. Further simulations indicated that a small molecule, forced into this conformation via two covalent attachment points to the fiber surface (similar to a 'horseshoe'), would provide similar adhesion improvements and confirm this conformational effect on interfacial phenomena. This prediction was confirmed by the synthesis and grafting of such a molecule to a carbon fiber surface, giving an almost identical improvement in interfacial adhesion (+276%). This work validates the use of molecular dynamics to inform molecular architectural design and demonstrates the translation of molecular conformation and shape at a composite interface from nano-to macroscale. Graphical abstract: Image 1