Zuo Zhiping, Liao Ruijin, Song Xiaoyu, Zhao Xuetong, Yuan Yuan
School of Automation, Chongqing University Chongqing 400044 China
State Key Laboratory of Power Transmission Equipment & System Security and New Technology, Chongqing University Chongqing 400044 China.
RSC Adv. 2018 May 30;8(36):19906-19916. doi: 10.1039/c8ra00712h.
To understand the effect of chemical composition on the anti-icing properties of a nanostructured superhydrophobic surface (SHP), four SHP surfaces were prepared on glass, which was initially roughed by a radio frequency (RF) magnetron sputtering method and then modified with HDTMS (a siloxane coupling agent), G502 (a partially fluorinated siloxane coupling agent), FAS-17 (a fully fluorinated siloxane coupling agent) and PDMS (a kind of polysilicone widely used in power transmission lines). Results show that the anti-icing properties of these four SHP surfaces in glaze ice varied wildly and the as-prepared SHP surface which was modified with FAS-17 (SHP-FAS) demonstrated a superior anti-icing/frosting performance. Approximately 56% of the entire SHP-FAS remained free of ice after spraying it for 60 min with glaze ice, and the average delay-frosting time (the time taken for the whole surface to become covered with frost) was more than 320 min at -5 °C. Equivalent model analysis indicates that Δ, defined as the difference in free energy of the Cassie-Baxter and Wenzel states, of the SHP-FAS is much lower than the other three SHP surfaces, giving priority to Cassie state condensation and the self-transfer phenomenon helping to effectively inhibit the frosting process by delaying the ice-bridging process, which is beneficial for improving the anti-frosting property. This work sheds light on and improves understanding of the relationship between anti-icing and anti-frosting properties and is helpful in making the optimum selection of a surface modifier for improving the anti-frosting/icing performances of a SHP surface.
为了解化学成分对纳米结构超疏水表面（SHP）防冰性能的影响，在玻璃上制备了四个SHP表面，玻璃首先通过射频（RF）磁控溅射法进行粗化处理，然后分别用HDTMS（一种硅氧烷偶联剂）、G502（一种部分氟化的硅氧烷偶联剂）、FAS - 17（一种全氟化的硅氧烷偶联剂）和PDMS（一种广泛应用于输电线路的聚硅氧烷）进行改性。结果表明，这四个SHP表面在 glaze 冰中的防冰性能差异很大，用FAS - 17改性制备的SHP表面（SHP - FAS）表现出优异的防冰/防霜性能。用glaze冰对SHP - FAS喷洒60分钟后，整个表面约56%仍未结冰，在-5°C时平均延迟结霜时间（整个表面被霜覆盖所需的时间）超过320分钟。等效模型分析表明，SHP - FAS的Δ（定义为Cassie - Baxter态和Wenzel态自由能之差）远低于其他三个SHP表面，优先发生Cassie态凝结，自转移现象有助于通过延迟冰桥形成过程有效抑制结霜过程，这有利于提高防霜性能。这项工作有助于揭示并增进对防冰和防霜性能之间关系的理解，有助于为改善SHP表面的防霜/防冰性能优化选择表面改性剂。
