TY - JOUR
T1 - Spontaneous Spreading of a Droplet
T2 - The Role of Solid Continuity and Advancing Contact Angle
AU - Jiang, Youhua
AU - Sun, Yujin
AU - Drelich, Jaroslaw W.
AU - Choi, Chang Hwan
N1 - Publisher Copyright:
© 2018 American Chemical Society.
PY - 2018/5/1
Y1 - 2018/5/1
N2 - Spontaneous spreading of a droplet on a solid surface is poorly understood from a macroscopic level down to a molecular level. Here, we investigate the effect of surface topography and wettability on spontaneous spreading of a water droplet. Spreading force is measured for a suspended droplet that minimizes interference of kinetic energy in the spontaneous spreading during its contact with solid surfaces of discontinuous (pillar) and continuous (pore) patterns with various shapes and dimensions. Results show that a droplet cannot spread spontaneously on pillared surfaces regardless of their shapes or dimensions because of the solid discontinuity. On the contrary, a droplet on pored surfaces can undergo spontaneous spreading whose force increases with a decrease in the advancing contact angle. Theoretical models based on both the system free energy and capillary force along the contact line validate the direct and universal dependency of the spontaneous spreading force on the advancing contact angle.
AB - Spontaneous spreading of a droplet on a solid surface is poorly understood from a macroscopic level down to a molecular level. Here, we investigate the effect of surface topography and wettability on spontaneous spreading of a water droplet. Spreading force is measured for a suspended droplet that minimizes interference of kinetic energy in the spontaneous spreading during its contact with solid surfaces of discontinuous (pillar) and continuous (pore) patterns with various shapes and dimensions. Results show that a droplet cannot spread spontaneously on pillared surfaces regardless of their shapes or dimensions because of the solid discontinuity. On the contrary, a droplet on pored surfaces can undergo spontaneous spreading whose force increases with a decrease in the advancing contact angle. Theoretical models based on both the system free energy and capillary force along the contact line validate the direct and universal dependency of the spontaneous spreading force on the advancing contact angle.
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U2 - 10.1021/acs.langmuir.8b00522
DO - 10.1021/acs.langmuir.8b00522
M3 - Article
C2 - 29629765
AN - SCOPUS:85046299077
SN - 0743-7463
VL - 34
SP - 4945
EP - 4951
JO - Langmuir
JF - Langmuir
IS - 17
ER -