Assessing the Critical Multifunctionality Threshold for Optimal Electrical, Thermal, and Nanomechanical Properties of Carbon Nanotubes/Epoxy Nanocomposites for Aerospace Applications

Abstract

Epoxy composites are widely used in primary aerospace structures, where high impact damage properties are necessary. However, challenges appear when multiple functionalities, including electrical and thermal conductivity, are needed in parallel with increased mechanical properties. The current study aims at the assessment of a critical concentration of multiwalled carbon nanotubes (MWCNTs), incorporated in epoxy resin, which will indicate a threshold for optimal electrical, thermal and mechanical properties. For the evaluation of this optimal concentration, electrical conductivity, thermal stability and nanomechanical properties (Young modulus and nanohardness) have been assessed, for epoxy nanocomposites with 0 to 15 parts per hundred resin per weight (phr) MWCNTs. Percolation theory was applied to study the electrical conductivity for different contents of MWCNTs in the epoxy nanocomposite system. Thermogravimetric analysis was employed for the assessment of the epoxy composites’ thermal properties. Nanohardness and elastic modulus were measured, and the hardness versus modulus index was calculated. Emphasis was given to the dispersion of MWCNTs in the epoxy matrix, which was assessed by both microscopy techniques and X-ray micro–computed tomography. A correlation between the optimum dispersion and MWCNTs content in terms of electrical conductivity, thermal stability, and nanomechanical properties revealed a threshold concentration at 3 phr, allowing the manufacturing of aerospace structures with multifunctional properties.

Heat Transfer at the Interface of Graphene Nanoribbons with Different Relative Orientations and Gaps

“…Similarly to the typical empirical expressions adopted for heat transfer, only basic formula building-blocks (i.e., constant, multiplication, division, power) have been considered for the Eureqa fitting. As a result, the simulation results in Table A1 (configurations N. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] have been found to be best fitted (R 2 = 0.99, see Figure 4b) by the following expression:…”

“…In fact, these materials show a remarkable combination of superior thermal [1][2][3][4], electrical [5][6][7], lubrication [8,9] and mechanical [10][11][12] properties, which have the potential to significantly enhance the performance of base materials. In particular, Polymer Nanocomposites (PNCs) with carbon nanofillers are currently employed in a broad variety of industries, such as the energy [13], aerospace [14], biomedical [15], electronics [16,17] and automotive ones [18,19].…”

End-of-Life Recycling Options of (Nano)Enhanced CFRP Composite Prototypes Waste—A Life Cycle Perspective

“…In this framework, carbon-based (nano)materials have been widely applied in the fields of environmental science [ 4 , 5 , 6 ], food industry [ 7 ], new transportation solutions [ 8 ], medicine [ 9 ] and health applications [ 10 , 11 ], energy [ 12 , 13 ], construction [ 14 ], electronics, sports, and so on. In addition, they have gained considerable ground in high-performance applications, such as the aerospace [ 8 , 15 ], marine [ 16 ], military [ 17 ], and automobile industries [ 18 ]. Especially, the last decade has seen a very significant increase in the use of carbon fibre reinforced polymers (CFRPs) [ 19 ], as shown in Figure 1 .…”

Investigating the Effect of Zn Ferrite Nanoparticles on the Thermomechanical, Dielectric and Magnetic Properties of Polymer Nanocomposites

“…By these means the next generation of polymer nanocomposites is expected to respond autonomously to as many external stimuli as possible and perform multiple functions exploiting their intrinsic properties, establishing thus their multifunctional performance. Epoxy resins are extensively used for the production of advanced composites in the fields of automotive, aerospace and electronics, mostly due to their high stiffness and good adhesion with the inclusions [33,34,35,36,37].…”