Surface wettability of water and blood on diversified nanocone‐shaped ZnO films modified with n‐dodecyl mercaptan

Abstract

How to understand the effect of the surface microstructures and chemical compositions on the anticoagulant properties is the key to develop novel anticoagulant materials. In view of the special surface microstructures and low surface free energy of superhydrophobic materials, it is expected that excellent anticoagulant properties can be obtained from superhydrophobic materials. Here, various nanocone‐shaped ZnO films were prepared by electrochemical deposition method followed by hydrothermal method and modified with n‐dodecyl mercaptan. Ordered nanocone‐shaped ZnO arrays are easier to obtain under suitable preparation conditions and can exhibit superhydrophobicity. The surface wettability is related to the ratio of the diameter and spacing (d/l) of ZnO nanocones. When the d/l value is 0.25–0.55, the contact angle (CA) is consistent with the Cassie mode; when the d/l value is 0.55–0.65, it corresponds to the Wenzel mode. Although the d/l value of the nanocones cannot directly determine the value of the surface free energy, which is strongly associated with the contact mode of the droplets on the film surface. Furthermore, the relationship among surface morphology, CA, and surface free energy is established, and the influence of surface morphology and surface free energy on blood contacting with foreign bodies is explored. It is found that the surface wettability of blood contacting with foreign bodies has some characteristics similar to that of general fluids. For example, under the same contact mode, although the CA of blood on the surface of ZnO nanofilms is about 20° smaller than that of water on the whole, the variation of CA with surface roughness is the same as that of general fluids. However, it also has some unique characteristics, such as the surface of ZnO nanofilms modified with hydrophobic material, the CA becomes larger. These characteristics are of special significance for the development of blood compatibility of superhydrophobic nanomaterials.