Influence of fullerene C60 impurities on spectral light absorption coefficients in technical fluids

Fullerene impurities in fluids have a significant influence on their thermophysical properties. Therefore, the use of various substances and materials with fullerene impurities opens up wide opportunities for improving the energy efficiency of equipment in which nanofluids are used: phase transition thermoaccumulative materials, working bodies and heat carriers. However, technological progress associated with the introduction of nanotechnologies in various equipment is largely hindered by the still unsolved problem of sedimentation and aggregation stability of nanofluids. And not only at the stage of nanomaterial production, but also during long-term operation in the equipment. The most reliable information about changes in the composition and structure of nanofluid can be obtained by spectral spectrophotometry. The proposed paper presents the results of the study of spectral absorption coefficients for several nanofluids: tetralin/fullereneC60, n-eicosane/fullerene C60 and Suniso 3GS/C60 compressor oil. Samples of different compositions were obtained within the framework of the proposed nanofluid creation technology. Spectrograms were obtained for the studied samples, from which it follows that with increasing concentration of fullerene C60 the spectral absorption coefficients increase in the interval of light wavelengths from 400 to 700 nm. The presence of extremum points on the dependences of spectral absorption coefficients of nanofluids tetralin/C60 and Suniso 3GS/C60 compressor oil in the wavelength range from 450 to 650 nm indicates that not only fullerene C60 molecules but also aggregates (nanoparticles) of different sizes are present in nanofluids.