Tuesday  |  Heritage E  |  09:20 AM–09:40 AM

#17382, Toughening Mechanism in Stacked Bilayer Graphene Sheet with Carbon Nanofibers

High intrinsic mechanical strength and modulus of 2D graphene (~130 GPa and ~1TPa respectively) has motivated the research in this field. However, resistance against the fracture in graphene is highly diminished due to the presence of manufacturing defects. It is generally hypothesized that the fracture toughness of pristine graphene can be elevated by incorporating 1D nanomaterials, such as carbon nanofibers, that helps to retard the crack advancement and increase the load bearing capacity of graphene. Here we have developed a technique to synthesize mixed dimensional carbon nanomaterials by deposition of carbon nanofibers on the graphene and sandwich it with another layer of graphene. We then studied the fracture toughness of the mixed dimensional nanomaterial and compared it with unreinforced graphene. The experiments provide high throughput insight around the crack tip and allow for real-time visualization of crack growth in bilayer graphene sheet suspended in the TEM grid. This study will provide a high-throughput fracture toughness characterization of mixed dimensional graphene sheets via applying known displacement fields on multiple graphene samples, each bound to an opening of a TEM grid. A real-time displacement-controlled load is applied to the graphene sheets in the SEM chamber to calculate the mode-I stress intensity factor as a function of crack length in large bilayer graphene. In combination with experimental data which will provide us the real-time displacement load boundary conditions, finite element analysis of mixed dimensional graphene will be used to measure the combinations of stress intensity values in mode-I for mode-I crack propagation and mode-I fracture toughness.

Usama Arshad   Texas A&M University
Yuxiang Gan   Texas A&M University
Chenglin Wu   Texas A&M University
Mohammad Naraghi   Texas A&M University