Scaling Laws and Mesoscopic Modeling of Heat Transfer in Nanofibrous Materials and Composites
Abstract
The structure -- thermal transport properties relationship for nanofibrous materials based on carbon nanotubes (CNTs) are investigated by performing a multiscale computational study combining atomistic molecular dynamics simulations of heat transfer in small groups of CNTs with mesoscopic modeling of thermal conductivity in CNT-based materials, such as CNT bundles, "buckypaper," and vertically-aligned CNT "forests." Some of the key results of this study are as follows. (1) General scaling laws governing the heat transfer in nanofibrous network materials with different structural organization are derived analytically and verified in mesoscopic simulations; (2) Contrary to the common assumption of the dominant effect of the contact CNT-CNT conductance, the contribution of intrinsic conductivity of CNTs is found to control the value of the effective conductivity of CNT networks at densities and CNT lengths typical for real materials; (3) Several distinct regimes of the acoustic energy dissipation are established in atomistic simulations of individual CNTs; (4) The dominant role of bending buckling in stabilization of CNT networks is revealed and the contribution of the thermal resistance of buckling kinks to the thermal conductivity of CNT materials is established.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 26, 2013
- Accession Number
- ADA595916
Entities
People
- Leonid V Zhigilei
Organizations
- University of Virginia