A series of nanofluids were prepared by incorporating titanium dioxide (TiO 2 ), carbon nanotube (CNTs) and zinc oxide (ZnO) into transformer oils to eliminate acetylene (C 2 H 2 ) bubbles, and elimination of the partial discharge (PD). The adsorption of C 2 H 2 molecules onto three model nanoparticles (TiO 2 , CNTs and ZnO) were simulated based on density functional theory (DFT) calculations, and then compared with ex- perimental data. Theoretically, TiO 2 showed the highest capacity for adsorbing C 2 H 2 molecules among the studied nanoparticles, as featured by a high adsorption energy (3.61 eV), high charge transfer (1.34 eV), and low equilibrium distance between TiO 2 and C 2 H 2 (2.55 ˚A). The maximum breakdown voltage was obtained at optimum CNTs, ZnO and TiO 2 contents of 0.01, 0.01, and 0.075 wt.%, respectively. Experimen- tal results confirmed theoretical calculations; so that TiO 2 had the highest efficiency of C 2 H 2 adsorption (71%), while ZnO and CNTs could adsorb acetylene by 64% and 17%, respectively. Moreover, CNTs and ZnO unenviably decreased the breakdown voltage by 77% and 27%, respectively, while TiO 2 increased it by 13%. Therefore, TiO 2 -based nanofluids not merely decreased the adverse effects of PD, but also improved the electrical properties of the transformer oil.
