Superhydrophobic and Anti‐Icing Coatings Made of Hierarchically Nanofibrillated Polymer Colloids
Superhydrophobic and Anti‐Icing Coatings Made of Hierarchically Nanofibrillated Polymer Colloids
复制标题
由分级纳米原纤化聚合物胶体制成的超疏水和防冰涂层
DOI：
10.1002/marc.202200513
复制
发表时间：
2022
影响因子：
4.6
通讯作者：
Velev, Orlin D.
中科院分区：
文献类型：
--
作者：
Williams, Austin H.;Roh, Sangchul;Kotb, Yosra;Velev, Orlin D.
由疏水和亲水聚合物沉积具有分级形态的涂层是制备超疏水和超亲水涂层的常用方法。这里报道的防水、吸水和防冰涂层是由一类称为软树枝状胶体（SDC）的材料制成的。在湍流介质中通过非溶剂诱导的相分离在悬浮液中产生支化的纳米纤维状SDC。比较了聚苯乙烯、聚乙烯醇和聚酯三种固体分散体的乙醇悬浮液干燥后形成的涂层的性能。高度支化的SDC形态产生缠结的多孔涂层，由于大量的亚接触，与“壁虎腿效应”类似，因此与基材具有强的物理粘附力。聚苯乙烯SDC涂层具有优异的超疏水性，但由于表面能低，附着力较弱。或者，聚乙烯醇SDC涂层显示出超亲水性和强粘附性，因为它们的高表面能。两种策略，以提高SDC层的粘附性和内聚性显示有效的-使用交织的网络和有机硅液滴微粘合剂。水的排斥力，以及混合的超疏水涂层中捕获的空气也使它们有效地对抗冰成核和粘附。最后，这些SDC制造具有类似特性的薄的、柔性的和耐用的非织造布。
The deposition of coatings with hierarchical morphology from hydrophobic and hydrophilic polymers is a common approach for making superhydrophobic and superhydrophilic coatings. The water‐repellent, water‐wicking, and anti‐icing coatings reported here are made from a class of materials called soft dendritic colloids (SDCs). The branched, nanofibrous SDCs are produced in suspension through nonsolvent‐induced phase separation in a turbulent medium. The properties of coatings formed by drying ethanol suspensions of SDCs made of polystyrene, polyvinyl alcohol, and polyester are compared. The highly branched SDC morphology creates entangled, porous coating layers with strong physical adhesion to the substrate due to the multitude of nanofiber sub‐contacts analogous to the “gecko leg effect”. Polystyrene SDC coatings show excellent superhydrophobicity but weaker adhesion due to low surface energy. Alternatively, polyvinyl alcohol SDC coatings show superhydrophilicity and strong adhesion from their high surface energy. Two strategies to improve the adhesivity and cohesivity of the SDCs layers are shown effective – use of intertwined networks and of silicone droplet microbinders. The water repulsion, together with the air trapped in the blended superhydrophobic coatings also makes them effective against ice nucleation and adhesion. Finally, these SDCs make thin, flexible, and durable nonwovens with similar properties.