The Effect of Outer Diameter of Multi-Walled Carbon Nanotubes on Fracture Behavior of Epoxy Adhesives

Abstract

KEYWORDSMulti-walled carbon nanotubes; Toughened adhesives; Fracture energy; Cohesive zone model; Double cantilever beam.Abstract. In this paper, the in uence of the outer diameter of multi-walled carbon nanotubes (MWCNTs) on the fracture behavior of epoxy adhesives was investigated experimentally and numerically. MWCNTs with three di erent outer diameters of less than 8, 20-30, and 50-80 nm were used to toughen the epoxy adhesive. Double Cantilever Beam specimens were tested to determine the fracture energy. The results indicated that improvement in the adhesive fracture resistance by introducing MWCNTs was considerably dependent on the outer diameter of MWCNTs. Toughening the epoxy adhesive by incorporating MWCNTs with 8 nm diameter improved the adhesive fracture energy three times higher compared to the MWCNTs with larger diameters. The SEM fractography of the fracture surfaces was also utilized to assess the governing fracture mechanisms occurred in the toughened epoxy adhesives. Moreover, a cohesive zone model was used for numerical investigation of the e ect of the MWCNT diameter on the damage behavior of epoxy adhesives.

Study on the Effects of the Interphase Region on the Network Properties in Polymer Carbon Nanotube Nanocomposites

“…By these explanations, it is concluded that the interphase plays an effective role in the percolation of nanoparticles. Figure 6 also reflects the roles of "R" and "t" parameters in the fraction of percolating network in the nanocomposites according to Equations (12) and (13) at φ f = 0.02, l = 5000 nm and A = 0.02. The smallest level of "R" and the largest value of "t" obtain the highest fraction of the network.…”

“…Many researchers have focused on polymer/carbon nanotubes (CNT) nanocomposites because their very low volume fractions show effective mechanical, thermal and chemical properties by preserving low density, transparency and simple processing [1][2][3][4][5][6][7][8][9][10]. The addition of CNT or graphene to polymers forms conductive nanocomposites, which has produced scientific interest in the research communities due to their potential applications in different fields, such as electronics and sensors [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25]. The experiments show the remarkable improvement of electrical conductivity of polymers by the addition of CNT.…”

“…The "f " parameter can be replaced by Equations (12) and (13). Also, the relative density of the filler network in the nanocomposites [45] is defined as:…”

Simulation of tunneling distance and electrical conductivity for polymer carbon nanotubes nanocomposites by interphase thickness and network density

“…The wonderful levels of mechanical, electrical, thermal, and physical properties of carbon nanotubes (CNT) have motivated the increasing interests for the investigation of composites containing CNT as polymer/CNT nanocomposites (PCNT) . The electrical conductivity of CNT reaches to 10 6 S/m, but the polymer matrices usually show the conductivity of 10 −16 to 10 −12 S/m .…”

Simple model for hydrolytic degradation of poly(lactic acid)/poly(ethylene oxide)/carbon nanotubes nanobiosensor in neutral phosphate‐buffered saline solution

“…Some authors combined PLA with carbon nanotubes (CNTs) because CNTs advantageously improve the degradation rate as well as the mechanical and electrical properties of polymers (Hasanzadeh et al, 2019;Irfan et al, 2019;Khoramishad, Khakzad, & Fasihi, 2017;Kim, Zare, Garmabi, & Rhee, 2018;Pavón et al, 2019;Roy, Petrova, & Mitra, 2018;Simonovic et al, 2018;Zare & Rhee, 2017a;Zhang et al, 2018). Chen et al (2013) reported a high degradation rate in poly(Llactide)/CNTs nanocomposites, which largely depended on the CNT content.…”