Ice shear fracture on nanowires with different wetting states

Understanding the function of nanoscale structure morphology in ice adhesion properties is important in deicing applications. The correlation between ice adhesion and nanowire morphology as well as the corresponding ice shear fracture mechanism are presented for the first time. Ice adhesion on nanowires was measured using a tangential ice-detaching instrument that was developed in-house. Stress analysis was performed using a COMSOL software. Nanowire surface shifted from Wenzel to Cassie transition and Cassie wetting states when the nanowire length was increased. Tangential ice-detaching forces were greater on the hydrophilic surface than those on the hydrophobic surface. Ice-ice internal shear fracture occurred on the ice and force probe contact area at the Wenzel state or on the ice and nanowire contact area at Cassie transition and Cassie state. Different lengths of nanowires caused different wetting states; thus, different fracture areas were formed, which resulted in different tangential ice-detaching forces. This paper presents a new way of tailoring surface ice adhesion via rational design of nanowire morphology with different wetting states.