Thesis
Nanoindentation of monolayer Ti_[n+1]C_nT_x MXenes via atomistic simulations
Master of Science (M.S.), Drexel University
May 2018
DOI:
https://doi.org/10.17918/yztg-j005
Abstract
Since their discovery in 2011, MXenes, two-dimensional transition metal carbides and/or nitrides, have been explored for uses in a wide range of applications due to their unique properties and facile synthesis methods. Despite this attention, there is a relative lack of understanding with regards to their fundamental mechanical properties. Here, nanoindentation of the MXene system Ti_[n+1]C_nT_x was studied via atomistic simulations utilizing a parametrization of the ReaxFF interatomic potential, to understand the influence of point defects. From force-displacement curves, the Young's moduli of pristine Ti₃C₂O2 and Ti2CO₂ were calculated to be 466 GPa and 983 GPa, respectively. The influences of both titanium and carbon vacancies on Ti₃C₂O2 were also quantified using simulated nanoindentation of a set of samples containing both 1% VTi and 10% VC, resulting in a reduction of the calculated Young's modulus to 386 ± 31 GPa. Of particular importance, is that these results are in good agreement with recent experimental findings indicating the important role defects play in determining the mechanical behavior of MXenes. The calculated Young's modulus in this work for the defect-containing Ti₃C₂O2 surpasses that of graphene oxide establishing it as a new benchmark in strength for solution-processed, 2D materials. Results here also indicate improvements can be made in current MXene processing methods to better approach the theoretical strength of pristine 2D materials.
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Details
- Title
- Nanoindentation of monolayer Ti_[n+1]C_nT_x MXenes via atomistic simulations
- Creators
- Gabriel Plummer - DU
- Contributors
- Garritt J. Tucker (Advisor) - Drexel University (1970-)
- Awarding Institution
- Drexel University
- Degree Awarded
- Master of Science (M.S.)
- Publisher
- Drexel University; Philadelphia, Pennsylvania
- Number of pages
- vii, 47 pages
- Resource Type
- Thesis
- Language
- English
- Academic Unit
- Materials (Science and) Engineering (Metallurgical Engineering) (1970-2026); College of Engineering (1970-2026); Drexel University
- Other Identifier
- 8263; 991014632931104721