Hubei Collaborative Innovation Centre for Advanced Organic Chemical Materials and Ministry of Education, Key Laboratory for the Green Preparation and Application of Functional Materials , Hubei University , Wuhan 430062 , People's Republic of China.
State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics , Chinese Academy of Sciences , Lanzhou 730000 , People's Republic of China.
ACS Appl Mater Interfaces. 2019 Oct 2;11(39):35949-35958. doi: 10.1021/acsami.9b08885. Epub 2019 Aug 26.
It is worth noting that the multifunctional surfaces are highly desirable for water collection applications on droplet nucleation and removal. Although the superhydrophobic surfaces is beneficial to water collection due to easily shed liquid drops and favorable heat-transfer performance, the pinned condensed water droplets within the rough structure and a high thermodynamic energy barrier for nucleation severely limit the water collection efficiency. Recently, the liquid-infused surfaces have been significant for condensation heat transfer and droplet nucleation but have poor durability. In this work, under the UV light, polydimethylsiloxane was grafted onto ZnO nanorods (through Zn-O-Si bond), and the residual unbonded silicone oil was used as the lubricant, so that it form a hierarchical lubricant-impregnated surfaces. Because of high viscosity of silicone oil and strong intermolecular force between silicone oil and PDMS brush, the lubricant can be firmly fixed in micronanostructure to form a durable lubricant layer. For example, the LISs have outstanding properties such as boiling water repellency, omniphobicity of various liquid, and hot water resistance. Under a self-made hot vapor collection device, the surface can maintain good water collection capacity and there is no obvious change in the lubrication layer. After exposing in sunlight for 7 days and subjecting them to 25 times heating/cooling cycles (heating at 150 °C), the LISs exhibit excellent water collection and repairability. After measurement, the oil content in the water is 43 mg/L, which is harmless to the human body. Through the high-water collection efficiency and durable lubricant layer, the LISs can be applied on a large scale in the water collection industry.
值得注意的是，多功能表面在液滴成核和去除方面对于集水应用非常理想。虽然超疏水表面由于易于去除液滴和良好的传热性能而有利于集水，但粗糙结构内的固定冷凝水滴和高热力学成核能垒严重限制了集水效率。最近，液体注入表面在冷凝传热和液滴成核方面具有重要意义，但耐久性差。在这项工作中，在紫外光下，将聚二甲基硅氧烷接枝到氧化锌纳米棒上（通过 Zn-O-Si 键），并且残留的未键合的硅油用作润滑剂，从而形成分层的润滑剂注入表面。由于硅油的高粘度和硅油与 PDMS 刷之间的强分子间力，润滑剂可以牢固地固定在微纳结构中以形成耐用的润滑层。例如，LIS 具有出色的性能，如沸水憎水性、各种液体的超疏油性和耐热水性。在自制的热蒸汽收集装置下，表面可以保持良好的集水能力，润滑层没有明显变化。在暴露在阳光下 7 天后并经受 25 次加热/冷却循环（在 150°C 下加热）后，LIS 表现出出色的集水和修复能力。测量后，水中的油含量为 43mg/L，对人体无害。通过高集水效率和耐用的润滑层，LIS 可以在集水行业大规模应用。
