超疏气微纳界面的设计制备及沸腾传热性能研究

Recently, with the increasing prominent environment problems and global energy shortage as well as demands in high heat flux dissipation of various high-performance electronic devices, designing and developing superaerophobic nanointerfaces with high-effective boiling heat transfer efficiency (BHTE) has attracted intensive interest. Although it’s been proved that the micro/nanostructure interface can improve BHTE effectively, the bubbles are easy to adhesive on the interface to form gas film and impede heat-transfer. Inspiration from the biomimic superaerophobic interface research, we will design and fabricate the micro/nanostructure with superaerophobicity function and study their enhancement of boiling heat transfer. Note that we will systematically monitor the dynamic behaviors of boiling bubbles on these interfaces, where their mass and heat transfer efficiency will be evaluated quantitatively, including the contact angle, adhesion force of bubbles and heat-transfer performance such as heat flux and heat transfer coefficient. These results can be used to reveal the influence rules of cooperation between the geometrical parameters and the wetting behavior of surface structure to control gas phase change behavior in microscale and enhancement of boiling heat transfer. Finally, we will optimize the crystal form of copper microstructure and the wetting behavior of boiling interfaces for developing one or two types of practical micro/nanointerfaces with high-efficiency boiling heat transfer performance. We believe that these findings will be helpful to design and develop high-performance material interfaces with enhancement of BHTE.

近年来，随着全球能源短缺和环境问题的日益突出以及高性能电子器件应用对高热流密度散热的迫切需求，设计开发具有高效沸腾传热性能的界面已引起广泛的兴趣。尽管已证实微纳结构能够实现沸腾传热效率的提升，但在沸腾传热过程中，气泡易与结构界面粘连形成气膜而阻碍热传递。受仿生超疏气界面的启发，本项目拟开展具有超疏气功能的微纳界面设计，同时将其应用于沸腾传热领域的研究。通过系统研究微纳界面的气泡动态行为（接触角、粘附力）及沸腾传热性能（热流密度及传热系数），来揭示表面结构、几何参数及浸润性的协同对微尺度气液相变行为及沸腾传热调控的影响规律。通过以上实验结果总结规律，为设计开发性能更卓越的沸腾传热材料界面提供实验依据。

受仿生超疏气界面的启发，本项目借助电化学沉积、化学镀、机加工等微纳加工手段，设计制备了具有超疏气功能的铜基微纳界面，同时将其应用于沸腾传热领域的研究。具体如下：1）通过一步电沉积法实现铜表面原位生长铜纳米锥的可控制备并考察其表面液滴及气泡浸润性；2）完成沸腾传热表征装备升级改造用于后续沸腾传热性能表征；3）铜表面原位生长铜纳米锥可实现沸腾传热性能显著提升；4）提出并证实了铜纳米锥表面复合低导热镍分级纳米锥后仍可实现沸腾传热性能大幅度提升；5）考察微柱图案复合铜纳米锥结构对沸腾传热性能的影响规律；6）探索槽型多孔微结构、微槽/铜纳米锥复合结构强化有机工质沸腾传热的可行性；7）在前一工作基础上，开发满足400W芯片散热的浸没式相变冷却散热器；8）探索机加工微槽复合铜纳米锥结构用于冷凝传热。其中，设计开发的低导热镍分级纳米锥包覆铜纳米锥结构可实现铜基沸腾传热系数最大提升228%。本项目的实验结果将有助于进一步设计开发性能更卓越的沸腾传热材料界面。截止项目结题验收时，共发表论文3篇、申请专利5项，各项考核指标均已完成。