Scalable manufacturing of hierarchical nanostructures for thermal management

The focus of this thesis is a new simple and scalable process to make surface coatings that have multiple length scales, or hierarchical features. Typically, the formation of hierarchical structures involves multiple steps and/or long processing times. In this new process, the hierarchical geometry is formed in a single step. The starting material-spherical copper powder-is oxidized in ambient air. Depending on the starting size of the powder, copper oxide nanowires may or may not form. Systematic thermogravimetric analysis (TGA) and in-situ x-ray diffraction (XRD) studies provide insights into the size-dependent thermal oxidation process. The proposed mechanism is supported by another interesting geometrical transformation: in the same single-step process, a large void is formed in the particles. The tunable nanowire growth is used to make new kinds of hierarchical coatings with enhanced heat-transfer performance in spray-cooling applications, which include nuclear reactor boiling, continuous casting of metals, and thermal management of electronics.

Department dc:contributor.department

Massachusetts Institute of Technology. Department of Mechanical Engineering

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2012

Author dc:creator

• Love, Christopher J., Ph.D. Massachusetts Institute of Technology

Advisor dc:contributor.advisor

• Kripa K. Varanasi.

• Mechanical Engineering.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/74926

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/74926