TY - JOUR
T1 - Generalized models for advancing and receding contact angles of fakir droplets on pillared and pored surfaces
AU - Jiang, Youhua
AU - Xu, Wei
AU - Sarshar, Mohammad Amin
AU - Choi, Chang Hwan
N1 - Publisher Copyright:
© 2019 Elsevier Inc.
PY - 2019/9/15
Y1 - 2019/9/15
N2 - Understanding how surface properties determine the mobility of a fakir droplet on patterned surfaces, which is typically characterized by advancing and receding contact angles, is important in the design of superhydrophobic surfaces for tailored applications. However, most analytical models of the contact angles are limited to a specific motion direction and surface type, e.g., receding on a pillared surface. Although it was suggested that the contact angles should be determined by the local configuration and dynamics of the droplet boundary, their link remains vague due to the lack of detailed visualizations. In this study, the contact line dynamics of a fakir droplet in both advancing and receding motions on not only micropillared but also micropored surfaces are visualized in reflection interference contrast microscopy along with the contact angle measurement. Based on the energy change induced by the displacement of a contact line and the deformation of a liquid-gas interface in between contact lines, theoretical models of the contact angles to encompass the two different motion directions and surface types are formulated. Moreover, further generalized models are established to serve as effective analytical models to predict the contact angles only based on the given structure dimensions and the inherent surface hydrophobicity.
AB - Understanding how surface properties determine the mobility of a fakir droplet on patterned surfaces, which is typically characterized by advancing and receding contact angles, is important in the design of superhydrophobic surfaces for tailored applications. However, most analytical models of the contact angles are limited to a specific motion direction and surface type, e.g., receding on a pillared surface. Although it was suggested that the contact angles should be determined by the local configuration and dynamics of the droplet boundary, their link remains vague due to the lack of detailed visualizations. In this study, the contact line dynamics of a fakir droplet in both advancing and receding motions on not only micropillared but also micropored surfaces are visualized in reflection interference contrast microscopy along with the contact angle measurement. Based on the energy change induced by the displacement of a contact line and the deformation of a liquid-gas interface in between contact lines, theoretical models of the contact angles to encompass the two different motion directions and surface types are formulated. Moreover, further generalized models are established to serve as effective analytical models to predict the contact angles only based on the given structure dimensions and the inherent surface hydrophobicity.
KW - Contact angle
KW - Contact line dynamics
KW - Droplet
KW - Pinning
KW - Superhydrophobic surface
UR - http://www.scopus.com/inward/record.url?scp=85066047656&partnerID=8YFLogxK
U2 - 10.1016/j.jcis.2019.05.053
DO - 10.1016/j.jcis.2019.05.053
M3 - 文章
C2 - 31132638
AN - SCOPUS:85066047656
SN - 0021-9797
VL - 552
SP - 359
EP - 371
JO - Journal of Colloid and Interface Science
JF - Journal of Colloid and Interface Science
ER -