A Thermal Switch from Thermoresponsive Polymer Aqueous Solutions

Thermal switch is very important in today’s world and it has varies of applications including heat dissipation and engine efficiency improving. The commercial thermal switch based on mechanical design is very slow and the structure is too complicated to make them smaller. To enable fast thermal switch as well as to make thermal switch more compact, I try to use second-order phase transition material to enable our thermal switch. Noticing the transition properties of thermoresponsive polymer for drug delivery, its potential in thermal switch can be expected. I used Poly(N-isopropylacrylamide) (PNIPAM) as an example to show the abrupt thermal conductivity change of thermoresponsive polymer solutions below and above their phase transition temperature. A novel technique, transition grating method, is used to measure the thermal conductivity. The ratio of thermal switch up to 1.15 in transparent PNIPAM solutions after the transition is observed. This work will demonstrate the new design of using second-order phase transition material to enable fast and efficient thermal switch.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Mechanical Engineering

Department dc:contributor.department

Mechanical Engineering

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

2018

Author dc:creator

• Ma, Yunwei

Chairs dc:contributor.committeechair

• Tian, Zhiting
• Huxtable, Scott T.

Committee member dc:contributor.committeemember

• Diller, Thomas E.

• Thermal conductivity
• Phase change
• Transient Grating

Statement dc:rights

• Creative Commons Attribution-NonCommercial 4.0 International

Licence dc:rights.uri

• http://creativecommons.org/licenses/by-nc/4.0/

Language dc:language.iso

en_US

Handle dc:identifier.uri

http://hdl.handle.net/10919/86837

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/86837