Thermal-lensing measurement of particle thermophoresis in aqueous dispersions
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چکیده
We show that thermophoresis (particle drift driven by thermal gradients) in aqueous solutions can be measured by using an all-optical thermal-lensing setup, where a temperature gradient is set by a near-infrared laser beam with no need of light-absorbing dyes. After discussing the principles of the method, we study by numerical simulation the nature and extent of parasitic thermal-convection effects, and we describe an optical setup designed to limit them. We finally present preliminary results on thermophoresis in micellar solutions and colloidal dispersions. © 2004 Optical Society of America OCIS codes: 350.6830, 220.4830, 000.6850, 190.4870, 160.6060.
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تاریخ انتشار 2004