AVS 51st International Symposium
    Materials Solutions for Cooling Technology Topical Conference Monday Sessions
       Session CT+TF-MoM

Paper CT+TF-MoM3
Interfaces, Functionalization and Heat Flow in Nanoscale Materials.

Monday, November 15, 2004, 9:00 am, Room 303B

Session: Thermal Transport in Thin Films and Nanostructured Materials
Presenter: S. Shenogin, Rensselaer Polytechnic Institute
Authors: S. Shenogin, Rensselaer Polytechnic Institute
A. Bodapati, Rensselaer Polytechnic Institute
L. Xue, Rensselaer Polytechnic Institute
P. Keblinski, Rensselaer Polytechnic Institute
Correspondent: Click to Email
The influence of the interface resistance on heat exchange between carbon nanotubes (CNs), fullerenes and embedding soft material medium was studied by means of molecular dynamics simulation. Due to a weak coupling between thermal vibrations of stiff carbon nanostuctures and soft organic matrix, the inclusion-matrix interface has high thermal resistance (Kapitza resistance). Recent experiments and simulations showed that the resistance of such interfaces is equivalent to the matrix layer with thickness 5 to 20 nm@footnote 1@,@footnote 2@. High boundary resistance considerably reduces thermal conductivity of the nanotube-based polymer composites and limits potential heat management applications. Our simulation shows that chemical functionalization of the nanoparticles with short organic chains reduces the interface thermal resistance by enhancing interactions between nanoparticels and the matrix. Detail dynamical analysis demonstrates that functionalization widens the overlap between the vibrational spectra of carbon nanostructures and the matrix. Remarkably, in the case of fullerenes, functionalization with a single chain reduces interfacial resistance by a factor of ~ 5. In the case of CN the interface resistance is reduced 4 times when 7 or more % of carbon atoms are functionalized. However, the functionalization decreases the intrinsic high thermal conductivity along the nanotube. The selection of the optimal side group length and concentration will be discussed. @FootnoteText@ @footnote 1@ S.T Huxtable et. al., Nature Materials, 2, 731 (2003).@footnote 2@ S.Shenogin et. al, J.Appl.Phys 95 (12), (2004).