Abstract
Measurements of particle flows driven by temperature gradients are conducted as a function of temperature on aqueous suspensions of polystyrene nanoparticles and proteins of T4 lysozyme and mutant variants of T4 lysozyme. The thermodiffusion coefficients are measured using a microfluidic beam deflection technique on suspensions with particle concentrations on the order of 1 vol %. At T ≲ 20 °C, all of the nanoparticles studied migrate to the hot regions of the fluid; i.e., the thermodiffusion coefficient is negative. At higher temperature, T ≳, 50 °C, the thermodiffusion coefficient is positive with a value consistent with the predictions of a theoretical model originally proposed by Derjaguin that is based on the enthalpy changes due to polarization of water molecules in the double layer.
Original language | English (US) |
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Pages (from-to) | 9221-9228 |
Number of pages | 8 |
Journal | Langmuir |
Volume | 23 |
Issue number | 18 |
DOIs | |
State | Published - Aug 28 2007 |
ASJC Scopus subject areas
- General Materials Science
- Condensed Matter Physics
- Surfaces and Interfaces
- Spectroscopy
- Electrochemistry