Experimental investigation of stability and thermo-physical properties of functionalized β-CD-TiO2-Ag nanofluids for antifreeze

Abstract

In the current work, β-CD-TiO2-Ag nanoparticles have been synthesized by modifying TiO2 nanoparticles with β-cyclodextrin and Ag elementary substance through building the bridge of coupling agent respectively. TEM was used to observe the morphology of nanoparticles. Crystalline structure of nanoparticles and functional groups of the surface of nanoparticles were tested by X-ray powder diffraction analysis and FT-IR spectrometer respectively. Two-steps method was applied to manufacture β-CD-TiO2-Agantifreeze-based nanofluids as novel antifreeze. And TLAB dispersion stability analyzer, Zeta PALS 190 Plus were used to test the stability of nanofluids. An important part of the present study focuses on the thermo-physical properties of β-CD-TiO2-Ag nanofluids. The experimental results indicated that the thermal conductivity enhancement of nanofluids compared to base fluids was evident because that the effect of thermal vibration intensity of antifreeze molecules in suspension increased and the intensity of micro motion of nanoparticles which is the main medium of energy transfer in nanofluids increased. Simultaneously, different thermal conductivity and rheological models have been compared with experimental data. It showed that the change trend was basically the same but there is a distance between them mainly because the ratio of water to ethylene glycol in base fluids was different and modified nanoparticles affect. This research will play an important role in application of functionalized nanoparticles in antifreeze.