胡琴,杨航,蒋兴良,舒立春.覆冰损伤后天然超疏水表面湿润性恢复机理研究[J].表面技术,2023,52(9):306-312.
HU Qin,YANG Hang,JIANG Xing-liang,SHU Li-chun.Wettability Recovery Mechanism of Natural Superhydrophobic Surface after Icing Damage[J].Surface Technology,2023,52(9):306-312 |
| 覆冰损伤后天然超疏水表面湿润性恢复机理研究 |
| Wettability Recovery Mechanism of Natural Superhydrophobic Surface after Icing Damage |
| 投稿时间：2022-09-05 修订日期：2022-12-20 |
| DOI：10.16490/j.cnki.issn.1001-3660.2023.09.026 |
| 中文关键词: 覆冰环境 超疏水 湿润性 恢复机理 |
| 英文关键词:icing environment superhydrophobicity wettability recovery mechanism |
| 基金项目:国家自然科学基金(51977016，52077020) |
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| Author | Institution |
| HU Qin | National Observation and Research Station for Xuefeng Mountain Energy Equipment Safety, Chongqing University, Chongqing 400044, China |
| YANG Hang | National Observation and Research Station for Xuefeng Mountain Energy Equipment Safety, Chongqing University, Chongqing 400044, China |
| JIANG Xing-liang | National Observation and Research Station for Xuefeng Mountain Energy Equipment Safety, Chongqing University, Chongqing 400044, China |
| SHU Li-chun | National Observation and Research Station for Xuefeng Mountain Energy Equipment Safety, Chongqing University, Chongqing 400044, China |
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| 中文摘要: |
| 目的 针对目前缺乏超疏水表面损伤后的湿润性恢复机理，揭示覆冰损伤后天然超疏水表面湿润性的恢复机理，以期为制备自恢复超疏水表面提供理论依据。方法 将荷叶置于低温低压人工试验室中，在不同“覆冰–脱冰”循环损伤次数后，使用共聚焦显微镜分别测量样品的湿润性、粗糙度，分别评价荷叶植株在“覆冰–脱冰”损伤后的湿润性及表面粗糙度的恢复过程，根据恢复过程特征分析恢复机理。结果 经“覆冰–脱冰”循环处理后的样品，其静态接触角降至105.34°~123.07°，滚动角增至39.5°~70.2°，表面算术平均高度（Sa）降至3.123~2.624 μm，表面均方根高度（Sq）降至3.542~3.113 μm；对于“覆冰–脱冰”循环损伤1次的荷叶植株，在48 h后其静态接触角恢复到150°以上。滚动角在24 h后降至10°以下。经3次“覆冰–脱冰”循环（约72 h）后，静态接触角、滚动角恢复到初始值。经过5次“覆冰–脱冰”循环损伤后，荷叶无法完成恢复过程，部分恢复湿润性后逐渐枯萎。结论 荷叶表面的静态接触角和滚动角恢复过程由表皮细胞重新扩张、表皮蜡层恢复2个因素决定。植株存活且表面局部损伤后，其静态接触角和滚动角都完全恢复，静态接触角更依赖于植物细胞和表皮蜡层所形成的微观粗糙度，而滚动角更依赖于微观粗糙度之上的纳观粗糙度，即滚动角比静态接触角更依赖于纳观粗糙度的恢复。 |
| 英文摘要: |
| In order to reveal the wettability recovery mechanism of the natural superhydrophobic surface after icing damage, lotus leaves were placed in a low-temperature and low-pressure artificial laboratory for the icing experiment. The icing test temperature was set to −5 ℃ and the wind speed was 1 to 3 m/s. The living lotus leaves were damaged by the cycle of "icing and deicing", and then recovered at room temperature. Wettability and roughness of the samples were measured by optical contact angle meter, digital tilt angle meter and 3D confocal microscope, respectively, to evaluate the wettability and surface roughness recovery process of lotus leaves after "icing and deicing" damage, and to analyze the recovery mechanism according to the characteristics of the recovery process. The static contact angle (WCA) decreased to 105.34°-123.07°, the slip angle (SA) increased to 39.5°-70.2°, the arithmetic average surface height (Sa) decreased to 3.123-2.624 μm, and the root mean square height (Sq) decreased to 3.542-3.113 μm, respectively. The wettability and roughness varied greatly from the initial values when a single "icing and deicing" cycle was carried out. As the number of cycles increased, the change gradually slowed down. In the subsequent action, the anchoring effect was not as strong as in the first cycle, so the surface roughness was not reduced as much as in the first cycle, and the change of wettability was not significant. For lotus leaves damaged once by the cycle of "icing and deicing", the WCA recovered to more than 150° after 48 hours. The SA dropped below 10° after recovery for 24 hours. About 72 hours after three cycles of "icing and deicing", WCA and SA returned to their initial values. After five cycles of "icing and deicing" damage, lotus leaves could not complete the recovery process. Although the absolute values of the surface roughness parameters are different after different cycles of "icing-deicing" damage, the recovery of surface roughness generally has an exponential function recovery process with time, which is consistent with the typical solid diffusion model. In particular, after multiple cycles of more severe damage, wettability has a short and sharp recovery phase at the initial stage, implying that there is a factor independent of diffusion, which is considered to be the cells re-expanded, and most living cells exhibit a weak temporal power-law viscoelastic deformation under mechanical loading. The shape of the cells can be recovered over time after the removal of the mechanical load. The viscoelasticity problem at the supracellular level can be explained by long-term mechanisms, with timescales ranging from tens of minutes to hours. The recovery process of WCA and SA on the lotus leaf surface is determined by two factors:the epidermal cells expanded again and the epidermal wax layer recovered. After plant survival and local surface damage, both WCA and SA are fully recovered. WCA is more dependent on the microscopic roughness formed by plant cells and the epidermal wax layer, while SA is more dependent on the nano-roughness attached to the microscopic roughness. SA is more dependent on the restoration of nano-roughness than WCA. |
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