Interfacial characterization of functionalized graphene-epoxy composites

Abstract

The interface of graphene/epoxy was studied using molecular dynamics simulations by calculating the work of separation and traction-separation responses in the normal mode. The influence of functionalization of the graphene layers on the traction-separation behaviour was also examined by grafting hydroxyl, carboxyl, and carbonyl groups. It is shown that the magnitude of the maximum traction is clearly larger for functionalized graphene/epoxy systems as compared to pristine graphene. The work of adhesion also shows a clear difference in the interface behaviour of functionalized graphene/epoxy and pristine/epoxy systems with the presence of functional groups generating higher values of work of separation.

Industrial manufacturing and characterization of multiscale CFRP laminates made from prepregs containing graphene-related materials

“…In this case, CFRP-rGO laminates presented 3% of improvement in strength compared to the CFRP laminate, what might indicate an enhancement in the interfacial adhesion [55,58,59]. The fact that the improvement is just seen in the CFRP-rGO could be related to the higher percentage of carboxyl groups (table 1), as the graphene-C=O/epoxy system present higher interface attraction than graphene/epoxy or graphene-OH/epoxy system [60]. The fact that CFRP-GNP laminate does not show a decrement in strength due to the presence of agglomeration could be due to the low GRM content, poor dispersion and the stress distribution in the tests (like the flexural test, figure S13) as explained above.…”

Interaction between carbon nanotubes with functional groups and epoxy resin and its effect on thermal properties of carbon nanotubes/epoxy composites

“…Hence, the interphase nature is a crucial factor that affects the performance of CNTs/epoxy composites, which is directly decided by the surface property of CNTs. [4][5][6][7][8][9][10] Liu et al 11 investigated the interphase structure between graphene (GP) and the epoxy matrix. It indicated that both interphase thickness and density of GP/epoxy composites are higher than those of GP oxide/epoxy composites.…”

“…Among the investigation, theoretical modeling techniques play an important role in understanding the interfacial interaction of composites. 7,13,18,24,28,32,[35][36][37][38][39][40][41][42] However, a direct experimental evidence of the interaction between CNTs and polymer before and after the composite preparation is still lacking. 17,33,34,[43][44][45] In this article, amino functionalized CNTs (NH 2 -CNTs) and hydroxyl functionalized CNTs (OH-CNTs), which are supposed to form different interfaces between CNTs and epoxy resin in composites, were investigated, and pristine CNTs (p-CNTs) were used for reference.…”

Mechanical behavior of electrophoretically modified CFRP composites at elevated temperatures: An assessment of the influence of graphene carboxyl bath concentration

“…In the past few years GBNs are under the limelight as ideal nanofillers for being used as reinforcements in various polymer and FRP composites because of their properties like high mechanical flexibility, the combination of high modulus and low weight, chemical stability, electrical conductivity, and various possible orientations 26–32 . The recent development is to modify the surface of the CFs with GBN by EPD route to augment the interfacial behavior of CFRP composites.…”

“…25 In the past few years GBNs are under the limelight as ideal nanofillers for being used as reinforcements in various polymer and FRP composites because of their properties like high mechanical flexibility, the combination of high modulus and low weight, chemical stability, electrical conductivity, and various possible orientations. [26][27][28][29][30][31][32] The recent development is to modify the surface of the CFs with GBN by EPD route to augment the interfacial behavior of CFRP composites. In an earlier study, graphene carboxyl (G COOH) was revealed to be the most supreme amongst various GBNs demonstrating a maximum improvement in both flexural strength (FS) and ILSS by bringing a uniform deposition of nanofiller on the surface of the CF.…”