Nanofluids were prepared by dispersing dodecanethiol-coated copper nanoparticles (~ 50 nm average diameter) in toluene. The stability and thermal conductivity of the nanofluids were investigated for various particle volume concentrations (0.09–1.5 vol%) and temperatures (293–333 K). The amount of dodecanethiol surfactant coated on the nanoparticle surface was determined by thermogravimetric analysis (TGA), and the chemical structure of adsorbed surfactant molecules was characterized by Fourier transform infrared spectroscopy (FT-IR). UV-vis absorbance analysis of the nanofluid was undertaken to determine the optimum ultrasonic vibration time for stability enhancement. The modeling study generated a new semi-practical correlation as a function of particle volume concentration and temperature for an existing Brownian motion–based thermal conductivity model, which demonstrated good compatibility with the present experimental measurements compared with other models.

通过将十二烷硫醇涂层的铜纳米颗粒（平均直径约为50 nm）分散在甲苯中来制备纳米流体。研究了纳米流体在各种颗粒体积浓度（0.09–1.5 vol％）和温度（293–333 K）下的稳定性和热导率。通过热重分析（TGA）确定涂覆在纳米颗粒表面上的十二烷硫醇表面活性剂的量，并且通过傅里叶变换红外光谱法（FT-IR）表征吸附的表面活性剂分子的化学结构。进行了纳米流体的紫外可见吸收分析，以确定增加稳定性的最佳超声振动时间。