铜基高效滴状冷凝传热纳米界面研究

In recent years, along with the increasingly prominent environment problem and global energy shortage as well as demands in high heat flux dissipation of various high-performance electronic devices, enhancing condensation heat transfer via surface nanoengineering has attracted intensive interest. Here, we focus on investigations into the topic “copper-based nanointerfaces with high-efficiency dropwise condensation heat-transfer performance”, which is characterized by frontier nanotechnology based on the interdiscipline of interface physical chemistry, materials science and thermal physics. Firstly, we will carry out the in-situ construction of copper-based condensate microdrop self-propelling (CMDSP) nanointerfaces, made of inorganic, inorganic- metal composite and metal materials, for enhancing condensate heat transfer. Based on this, various hydrophilic micro-patterns with controllable shapes, sizes, interspaces and arrangement ways will be introduced onto the copper-based CMDSP surfaces via template-assisted heterogeneous chemical modification for exploring their remarkable potential in enhancing condensate heat transfer. Note that we will systematically monitor the dynamic behaviors of condensate microdrops on these two types of CMDSP surfaces, where their mass and heat transfer efficiency will be evaluated quantitatively, including the departing sizes, renewal frequency and nucleation density of condensate microdrops and heat-transfer performance such as heat flux and heat transfer coefficient. These findings help reveal the influence rules of cooperation of surface structure, materials component and surface chemistry to condensate heat transfer enhancement. Finally, we will optimize the nanofabrication technologies for developing one to two types of practical copper-based nanointerfaces materials with high-efficiency dropwise condensation heat transfer performance. We believe that these findings help design and develop high-performance flat heat pipe and devices for efficient thermal management and energy utilization.

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，强化冷凝传热已引起高度关注。申请人聚焦界面物化、材料及热物理等多学科交叉的“铜基高效滴状冷凝传热纳米界面研究”这一新兴前沿纳米科技，拟重点开展铜基表面不同材质冷凝微滴自驱离功能纳米界面的原位构筑及强化冷凝传热的研究；在此基础上，拟利用掩模板辅助的非均相化学修饰技术在铜基冷凝微滴自驱离功能纳米表面引入图案化的亲水位点，并考察这种杂化界面高效冷凝传热潜力。针对上述功能纳米结构，我们将系统研究其表面冷凝微滴动态行为（脱离尺寸、更新频率及成核密度）及传热性能（热流密度及传热系数），揭示表面结构、材料组成及表面化学的协同对微尺度气液相变行为调控及冷凝传热强化的影响规律；在此基础上，我们拟针对铜基表面开发一两种有实用化潜力的高效滴状冷凝传热界面材料。相关成果预计有助于设计开发高性能平板热管及热控器件。

电子器件的微型化、集成化、大功率化发展对小空间高热流散热提出了迫切需求，高效冷凝传热界面研究已引起广泛关注。项目任务书设定的各课题已完成，主要包括：1）针对铜表面高效传质传热需求，先后设计制备了不同材质不同构型超疏水纳米界面（如氧化锌纳米针、氧化锌纳米铅笔、氧化锌纳米刺管、氧化铈纳米粒子多孔膜、氧化铜纳米片、镍纳米锥、氢氧化铜棱槽纳米针），系统考察了这些构型在大气工况下的冷凝传质性能，已证实密排列纳米针构型具有相对最优的小尺度冷凝微滴高密度自弹射去除性能（该构型被筛选用于不同图案化亲水微区复合及冷凝传质传热效应研究）；2）冷凝传热表征设备核心模块（蒸汽发生单元、冷凝腔、冷却单元）已按计划进行了升级改造；3）系统开展了不同反应时间超疏水氧化锌纳米针构型在蒸汽工况下的冷凝传质传热性能评估，揭示了构效关系并获得传热性能最优的纳米样品，其冷凝传热系数相比光滑疏水铜表面可增强320%，增强因子国际领先；4）巧妙利用冷凝微滴选择性捕获聚乙烯醇雾滴实现亲水微区的引入，优化的亲疏水复合样品相比空白疏水表面具有更优异的冷凝成核及微滴自去除能力，其冷凝液滴直径降低了75%、液滴密度和去除速率提升了240%和387%；5)提出并证明了超疏水表面复合空间非均相排列的超亲水微区图案可实现冷凝微滴限域生长并协同可控自去除策略的可行性，优化的非均相图案的单位面积单位时间排液量是均相图案的350%，是超疏水表面的1020%，协同可控去除比随机去除更高效；6）非均相图案在低温蒸汽工况下也能实现微滴限域生长并协同可控自去除，其冷凝传热效率优于空白超疏水表面。与此同时，我们还探索了非任务书设定的其它课题：1）提出并证明了超疏水表面复合非均相疏水微腔图案实现冷凝微滴限域生长并可控协同去除的新策略；2）探索了铜基铜纳米锥的原位生长、密度调控及最密铜纳米锥样品在不同蒸汽温度下的冷凝传质传热性能。部分工作已发表在Adv. Mater.、Adv. Funct. Mater.等杂志。