Bregar Tadej, Vodopivec Matevž, Pečnik Tim, Zupančič Matevž, Golobič Iztok
Faculty of Mechanical Engineering, University of Ljubljana, Aškerčeva 6, 1000 Ljubljana, Slovenia.
Nanomaterials (Basel). 2022 Aug 12;12(16):2772. doi: 10.3390/nano12162772.
The pool-boiling performance of water on thin metal foils with graphene-oxide deposition was studied. The boiling performance was evaluated both on fully coated surfaces, achieved by spin-coating, and surfaces with a laser-textured nucleation site, into which graphene oxide was added via drop-casting. During the experiments, a high-speed IR camera was used to obtain the transient temperature and heat-flux distribution. At the same time, a high-speed video camera was used to acquire synchronized bubble-growth recordings. In addition, a surface-wettability analysis was conducted for all the samples. In the case of fully coated samples, graphene-oxide deposition resulted in an increased number of active nucleation sites and an increase in the nucleation temperature, leading to a lowered nucleation frequency. Meanwhile, samples with a single laser-textured nucleation site enabled the analysis of isolated vapor bubbles, confirming that graphene-oxide deposition leads to a higher nucleation temperature, consequently resulting in a larger bubble-departure diameter and longer growth time. Two explanations for the results are proposed: the wettability of graphene-oxide deposition and the filling of surface microcavities with graphene-oxide nanoflakes.
研究了氧化石墨烯沉积在薄金属箔上时水的池沸腾性能。通过旋涂在完全涂覆的表面以及具有激光纹理化成核位点的表面（通过滴铸法向其中添加氧化石墨烯）上评估沸腾性能。在实验过程中，使用高速红外摄像机获取瞬态温度和热流分布。同时，使用高速摄像机获取同步的气泡生长记录。此外，对所有样品进行了表面润湿性分析。对于完全涂覆的样品，氧化石墨烯沉积导致活性成核位点数量增加且成核温度升高，从而降低了成核频率。同时，具有单个激光纹理化成核位点的样品能够分析孤立的蒸汽泡，证实氧化石墨烯沉积导致更高的成核温度，进而导致更大的气泡脱离直径和更长的生长时间。针对这些结果提出了两种解释：氧化石墨烯沉积的润湿性以及氧化石墨烯纳米片对表面微腔的填充。
