将纳米TiO₂按照质量分数2%分散在乙醇溶液中,通过沉积法将TiO₂沉积在泡沫铜骨架上,制备出纳米TiO₂复合泡沫铜表面。通过环境扫描电镜(SEM)观察其沉积情况,发现随着TiO₂沉积量的增加,泡沫铜骨架被覆盖的部分逐渐增加,其中沉积量为2.5 mL TiO₂的泡沫铜表面覆盖效果最好,其骨架完全被TiO₂颗粒覆盖且泡沫铜的孔隙没有被堵塞。以水为工质对复合表面进行沸腾性能测试,发现沉积TiO₂乙醇分散液体积为2.5 mL时表面传热性能最佳,传热系数是未沉积有TiO₂的泡沫铜表面的1.5倍,热通量增加了170 kW/m²。通过沸腾可视化图像可看出,TiO₂沉积量为2.5 mL的泡沫铜表面产生的气泡数量多,且不易合并,说明沉积的纳米TiO₂增加了表面的核化点,且提高了表面的毛细吸力,加速了液体回流。

Nano-TiO₂ is dispersed in ethanol solution at a 2% mass fraction,and deposited on a copper foam skeleton via the deposition method to prepare nano-TiO₂ composite copper foam surface.The deposition situation is observed by means of scanning electron microscopy.It is found that the covered portion of copper foam skeleton increases gradually with the increase of the deposited TiO₂ content.The surface coverage of copper foam with 2.5 mL of TiO₂ deposited reaches the best,and the skeleton has been completely covered by TiO₂ particles while the pores of copper foam are not blocked.Boiling performance of composite surface is tested with water as the working medium,and it is indicated that the composite surface prepared with 2.5 mL of TiO₂ ethanol dispersion solution exhibits the best heat transfer performance,its heat transfer coefficient is 1.5 times that of the copper foam surface without TiO₂ deposition,and its heat flux is 170 kW·m^-2 higher.It can be seen from the boiling visualization images that the composite surface prepared with 2.5 mL of TiO₂ ethanol dispersion solution produces a large number of bubbles that do not merge easily,indicating that the deposited titanium dioxide nanoparticles increases the nucleation sites on the surface,improves the capillary suction on the surface and accelerates the liquid reflux.

高向阳(1996-),男,硕士生,研究方向为多孔介质表面相变传热,497013462@qq.com