Effects of Conformal Nanoscale Coatings on Thermal Performance of Vertically Aligned Carbon Nanotubes

Abstract

The high aspect ratio and the porous nature of spatially oriented forest-like carbon nanotube (CNT) structures represent a unique opportunity to engineer a novel class of nanoscale assemblies. By combining CNTs and conformal coatings, a 3D lightweight scaffold with tailored behavior can be achieved. The effect of nanoscale coatings, aluminum oxide (Al O ) and nonstoichiometric amorphous silicon carbide (a-SiC), on the thermal transport efficiency of high aspect ratio vertically aligned CNTs, is reported herein. The thermal performance of the CNT-based nanostructure strongly depends on the achieved porosity, the coating material and its infiltration within the nanotube network. An unprecedented enhancement in terms of effective thermal conductivity in a-SiC coated CNTs has been obtained: 181% compared to the as-grown CNTs and Al O coated CNTs. Furthermore, the integration of coated high aspect ratio CNTs in an epoxy molding compound demonstrates that, next to the required thermal conductivity, the mechanical compliance for thermal interface applications can also be achieved through coating infiltration into foam-like CNT forests.

A Facile Fabrication and Transfer Method of Vertically Aligned Carbon Nanotubes on a Mo/Ni Bilayer for Wearable Energy Devices

“…Such VACNTs are generally synthesized by high‐temperature chemical vapor deposition (CVD) processes. [ 18,19 ] However, typical deformable substrates for wearable devices are made of polymers and/or elastomers that are vulnerable to high temperature. Therefore, in order to utilize the VACNTs to fabricate wearable devices, they should be transferred from a rigid substrate for CNT growth to a flexible substrate for device fabrication.…”

Vertically-Aligned Multi-Walled Carbon Nano Tube Pillars with Various Diameters under Compression: Pristine and NbTiN Coated

“…Beside the investigation of pristine CNTs, researchers have made a considerable effort to optimize the full potential of individual CNTs by application of conformal coatings of metal [ 32 ], ceramic [ 33 ] or even graphene [ 34 ]. Coated CNT arrays have received significant attention for potential use in electrical [ 35 ], optical [ 36 ], thermal [ 37 ], chemical [ 38 ], and mechanical [ 31 ] fields. Though the compressive performance of coated CNTs is expected to contribute significantly to the performance of these applications, relatively little is known about the collective mechanical behavior of coated CNT arrays and how their morphology may influence the mechanical response.…”

Study of the synergistic effect of boron nitride and carbon nanotubes in the improvement of thermal conductivity of epoxy composites

“…According to their exceptional properties, they can be used in a wide range of applications in the fields of aerospace, automotive and naval engineering, light‐emitting diodes (LEDs) and biomedicine, among others . Among the various synthetic methodologies, chemical vapour deposition appears as the most convenient, since it is the most economical and the obtained nanotubes have more defects, which improves the interaction capability with a matrix, improving the interface properties . One of the main problems to be solved in the preparation of composites is the dispersion of CNTs in the matrix which is hindered due to their high surface area and their strong tendency to agglomerate via van der Waals forces .…”

“…17,18 Among the various synthetic methodologies, chemical vapour deposition appears as the most convenient, since it is the most economical and the obtained nanotubes have more defects, which improves the interaction capability with a matrix, improving the interface properties. 19,20 One of the main problems to be solved in the preparation of composites is the dispersion of CNTs in the matrix which is hindered due to their high surface area and their strong tendency to agglomerate via van der Waals forces. 11,13 The other important issue is the high interfacial thermal resistance between nanofiller and polymeric matrix.…”