Enhancing the fracture toughness of hierarchical composites through amino‒functionalised carbon nanotube webs

[EN] The introduction of carbon nanotubes (CNTs) in structuralfibre-reinforced polymers, to imbue the compositewith multifunctional properties (e.g. enhancing electrical/thermal conductivity, structural health monitoring),has received much attention in recent years. Maintaining, and preferably enhan...

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Detalles Bibliográficos
Autores: Nistal, Andrés, Falzon, Brian G., Hawkins, Stephen C., Chitwan, Ravi, García Diego, Cristina, Rubio Alonso, Fausto
Tipo de recurso: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2019
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/212706
Acceso en línea:http://hdl.handle.net/10261/212706
Access Level:acceso abierto
Palabra clave:Carbon nanotubes
Functional composites
Surface treatments
Fracture toughness
Interface
Descripción
Sumario:[EN] The introduction of carbon nanotubes (CNTs) in structuralfibre-reinforced polymers, to imbue the compositewith multifunctional properties (e.g. enhancing electrical/thermal conductivity, structural health monitoring),has received much attention in recent years. Maintaining, and preferably enhancing, the structural integrity ofthe composite is imperative. Consequently, strong interfacial bonding between the CNTs and the polymer matrixis sought. If the sought multifunctionality is dependent on specific CNT alignment or orientation, achievedthrough fragile CNT assemblies, gas‒phase chemical functionalisation of the CNT assembly is a viable approachin order to chemically modify the CNT surface without damaging the CNT assembly. This study reports on thegas‒phase amino‒functionalisation of CNT webs (CNTw) and further explores its influence on thein situelec-trical conductivity. The placement of an ethylenediamine-functionalised multilayer CNTw (0.2 g m−2) betweenCF plies resulted in a 13% enhancement in the interlaminar Mode I fracture toughness, while providing anelectrical conductivity of 103Sm−1in the direction of the CNTs within the interleaved CNTw. The effectivenessof the amino‒functionalised CNTw in enhancing the mechanical properties of an epoxy composite is related toan epoxy opening reaction, as demonstrated by Differential Scanning Calorimetry (DSC). Raman and X-rayphotoelectron spectroscopies are used to confirm that gas‒phase amino‒functionalisation does not damage thegraphene-based structure and its structural dependent properties.