Measurement of thermo-optic coefficient of silicon dioxide nanofluid using interferometer

Abstract

Nanofluid technology has attracted considerable research attention in recent years. A Michelson interferometer was constructed, and a silicon dioxide (SiO2) nanofluid was placed in the optical path. The thermo-optic coefficient (TOC) was obtained by counting the moving interference fringes while increasing the nanofluid temperature. Two nanofluid samples were prepared by dispersing 20 nm and 80 nm SiO2 nanospheres in distilled water and conducting the experiments at two wavelengths, 532 nm and 633 nm. In the 20 nm SiO2 nanofluid, the TOC changed from 8.038 × 10-5/ºC to 1.695 × 10-4/ºC as the temperature was increased from room temperature to 70°C at a wavelength of 532 nm, and the TOC was changed from 6.634 × 10-5/ºC to 1.534 × 10-4/ºC at a wavelength of 633 nm. In the 80 nm SiO2 nanofluid, the TOC changed from 1.322 × 10-4/ºC to 2.359 × 10-4/ºC as the temperature was increased from room temperature to 70°C at a wavelength of 532 nm, and the TOC changed from 1.138 × 10-4/ºC to 2.261 × 10-4/ºC at a wavelength of 633 nm.