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Atomistic Investigation of Load Transfer Between DWNT Bundles “Crosslinked” by PMMA Oligomers
Author(s) -
Naraghi Mohammad,
Bratzel Graham H.,
Filleter Tobin,
An Zhi,
Wei Xiaoding,
Nguyen SonBinh T.,
Buehler Markus J.,
Espinosa Horacio D.
Publication year - 2013
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.201201358
Subject(s) - materials science , van der waals force , carbon nanotube , surface modification , polymer , toughness , composite material , shearing (physics) , methyl methacrylate , nanotechnology , chemical engineering , polymerization , molecule , chemistry , organic chemistry , engineering
The production of carbon nanotube (CNT) yarns possessing high strength and toughness remains a major challenge due to the intrinsically weak interactions between “bare” CNTs. To this end, nanomechanical shear experiments between functionalized bundles of CNTs are combined with multiscale simulations to reveal the mechanistic and quantitative role of nanotube surface functionalization on CNT‐CNT interactions. Notably, the in situ chemical vapor deposition (CVD) functionalization of CNT bundles by poly(methyl methacrylate) (PMMA)‐like oligomers is found to enhance the shear strength of bundle junctions by about an order of magnitude compared with “bare” van der Waals interactions between pristine CNTs. Through multiscale simulations, the enhancement of the shear strength can be attributed to an interlocking mechanism of polymer chains in the bundles, dominated by van der Waals interactions, and stretching and alignment of chains during shearing. Unlike covalent bonds, such synergistic weak interactions can re‐form upon failure, resulting in strong, yet robust fibers. This work establishes the significance of engineered weak interactions with appropriate structural distribution to design CNT yarns with high strength and toughness, similar to the design paradigm found in many biological materials.