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THERMAL TRANSPORT IN NOVEL THREE DIMENSIONAL CARBON NANOSTRUCTURES

Park, Jungkyu
http://rave.ohiolink.edu/etdc/view?acc_num=case1455101197

Abstract Details

2016, Doctor of Philosophy, Case Western Reserve University, EMC - Mechanical Engineering.
Three-dimensional (3D) nanostructures comprised of one-dimensional (1D) and/or two-dimensional (2D) nanomaterials have several advantages over their base nanomaterials. Due to their dimensionally confined structures, for example, 1D carbon nanotubes (CNTs) and 2D graphene exhibit strong direction-dependent thermal transport properties with extremely inefficient cross-plane properties. However, 3D carbon nanostructures such as pillared graphene structures (PGS) are expected to be efficient in both in-plane and cross-plane thermal transport. The aim of this thesis is providing the detailed understanding of thermal transport in 3D carbon nanostructures comprised of CNTs and graphene. Reverse non-equilibrium molecular dynamics simulations were used to show that PGS and CNT networks can have both high in-plane and high cross-plane thermal conductivities comparable to their base nanomaterials, i.e. CNTs and graphene, and also to show that their thermal properties are tunable through altering their architectures. The results indicate that thermal resistances at CNT-graphene junctions result from the combined effect of phonon scattering at the junctions with distorted carbon-carbon bonds and the change in dimensionality of the phonon transport medium as phonons propagate from CNTs (1D) to graphene (2D) and then again to CNT. Moreover, wave packet analysis on SWCNT networks revealed that SWCNT-SWCNT junctions with lager diameter transmit thermal energy more efficiently than the junctions with smaller diameter, and also revealed that SWCNT-SWCNT T-junctions are more efficient in thermal energy transmission than X-junctions. A new experimental method for thermal conductivity measurements in 2D nanosheets was developed. The new method ensures a 1D heat conduction in a 2D sample by creating a spatially uniform temperature profile on the heated side of the sample, and thus improves the accuracy of the measurement in a 2D structure. A MEMS device that can measure the thermal conductivity of a graphene layer using this method is currently being fabricated for the validation of the method.
Vikas Prakash (Committee Chair)
258 p.
Mechanical Engineering; Nanotechnology
3D carbon, Molecular Dynamics, Thermal Conductivity, Carbon Nanotube, Graphene, Measurement

Recommended Citations

Citations

  • Park, J. (2016). THERMAL TRANSPORT IN NOVEL THREE DIMENSIONAL CARBON NANOSTRUCTURES [Doctoral dissertation, Case Western Reserve University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=case1455101197

    APA Style (7th edition)

  • Park, Jungkyu. THERMAL TRANSPORT IN NOVEL THREE DIMENSIONAL CARBON NANOSTRUCTURES. 2016. Case Western Reserve University, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=case1455101197.

    MLA Style (8th edition)

  • Park, Jungkyu. "THERMAL TRANSPORT IN NOVEL THREE DIMENSIONAL CARBON NANOSTRUCTURES." Doctoral dissertation, Case Western Reserve University, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=case1455101197

    Chicago Manual of Style (17th edition)

case1455101197
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© 2016, all rights reserved.
This open access ETD is published by Case Western Reserve University School of Graduate Studies and OhioLINK.