A Nanometric View into Strengthening Mechanisms of Iron Incorporation in Graphene-Based Nanocomposites
Author
Rand, MatthewIssue Date
2018Keywords
Graphene OxideGraphite Intercalation Compound
Mechanical Properties
Molecular Dynamics
Simulation
Advisor
Muralidharan, Krishna
Metadata
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The University of Arizona.Rights
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction, presentation (such as public display or performance) of protected items is prohibited except with permission of the author.Abstract
Recent advances in the ability to synthesize metal-ion coagulated graphene oxide (GO) colloidal dispersions have provided new avenues for fabrication of GO based thin films and membranes. Additionally, new fabrication techniques have recently emerged that enable the ability to intercalate and reduce metal halides in bulk graphite crystals, leading to metal-based graphite intercalated compounds (GICs). To this end, a fundamental study on the interplay between composition, atomic-scale structure and mechanical properties of metal-GO as well as metal-GIC composite materials was carried out employing molecular dynamics (MD) simulations. Specifically, the transition metal iron (Fe) was considered in this study; MD investigations reveal that Fe ions act as strong cross-linkers between individual GO sheets, increasing elastic modulus as well as tensile strength of the Fe-GO composite. Investigations of Fe intercalated GIC (Fe-GIC) showed interesting trends in its mechanical properties due to bond formation between the intercalated Fe atoms and the ‘sandwiching’ graphene sheets. In particular, with increasing iron concentration, there is strengthening in the out-of-plane direction, while reduction in the in-plane direction of the Fe-GIC lattice. While the Fe-C bonding ensures out-of-plane strengthening, it is equally detrimental to the strength of the in-plane C-C bonds within the graphene sheets. Valuable lessons learned from this work provide important insights into the design and development of GO and GIC composites for targeted mechanical and chemical applications.Type
textElectronic Thesis
Degree Name
M.S.Degree Level
mastersDegree Program
Graduate CollegeMaterials Science & Engineering