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Wetting on flexible hydrophilic pillar-arrays.

Yuan Q, Zhao YP - Sci Rep (2013)

Bottom Line: For the first time, the combined effect of the surface topology, the intrinsic wettability and the elasticity of a solid on the wetting process is taken into consideration.Scaling analysis is performed based on molecular kinetic theory and validated by our simulations.Our results may expand our knowledge of wetting on pillars and assisting the future design of active control of wetting in practical applications.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Nonlinear Mechanics, Institute of Mechanics, Chinese Academy of Sciences, Beijing, People's Republic of China.

ABSTRACT
Dynamic wetting on the flexible hydrophilic pillar-arrays is studied using large scale molecular dynamics simulations. For the first time, the combined effect of the surface topology, the intrinsic wettability and the elasticity of a solid on the wetting process is taken into consideration. The direction-dependent dynamics of both liquid and pillars, especially at the moving contact line (MCL), is revealed at atomic level. The flexible pillars accelerate the liquid when the liquid approaches, and pin the liquid when the liquid passes. The liquid deforms the pillars, resulting energy dissipation at the MCL. Scaling analysis is performed based on molecular kinetic theory and validated by our simulations. Our results may expand our knowledge of wetting on pillars and assisting the future design of active control of wetting in practical applications.

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Related in: MedlinePlus

Illustrations of a droplet wetting (a) on rigid pillar-arrays, and (b) on flexible pillar-arrays.(c–d) Experiments of a droplet wetting on flexible polydimethylsiloxane (PDMS) pillar-arrays (Y = 2.2 MPa).
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f1: Illustrations of a droplet wetting (a) on rigid pillar-arrays, and (b) on flexible pillar-arrays.(c–d) Experiments of a droplet wetting on flexible polydimethylsiloxane (PDMS) pillar-arrays (Y = 2.2 MPa).

Mentions: Dynamic wetting on the hydrophilic pillar-arrays, where physics12, chemistry34, biology56, and materials science78 intersect, is of great interest. Influenced by the combined effect of the surface topology and the intrinsic wettability of the solid, dynamic wetting on the pillars becomes rather complicated9. The topology enhances wettability, making the substrate superhydrophilic10. As shown in Fig. 1(a, c), a droplet on pillars is divided into two parts: the lower fringe penetrates into the spaces between pillars, whilst the upper bulk droplet spreads on the fringe. There are two important quantities to describe the pillar-arrays: surface roughness and density of the roughness , where d, h and p are the size, the height and the period of pillars, respectively.


Wetting on flexible hydrophilic pillar-arrays.

Yuan Q, Zhao YP - Sci Rep (2013)

Illustrations of a droplet wetting (a) on rigid pillar-arrays, and (b) on flexible pillar-arrays.(c–d) Experiments of a droplet wetting on flexible polydimethylsiloxane (PDMS) pillar-arrays (Y = 2.2 MPa).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3672886&req=5

f1: Illustrations of a droplet wetting (a) on rigid pillar-arrays, and (b) on flexible pillar-arrays.(c–d) Experiments of a droplet wetting on flexible polydimethylsiloxane (PDMS) pillar-arrays (Y = 2.2 MPa).
Mentions: Dynamic wetting on the hydrophilic pillar-arrays, where physics12, chemistry34, biology56, and materials science78 intersect, is of great interest. Influenced by the combined effect of the surface topology and the intrinsic wettability of the solid, dynamic wetting on the pillars becomes rather complicated9. The topology enhances wettability, making the substrate superhydrophilic10. As shown in Fig. 1(a, c), a droplet on pillars is divided into two parts: the lower fringe penetrates into the spaces between pillars, whilst the upper bulk droplet spreads on the fringe. There are two important quantities to describe the pillar-arrays: surface roughness and density of the roughness , where d, h and p are the size, the height and the period of pillars, respectively.

Bottom Line: For the first time, the combined effect of the surface topology, the intrinsic wettability and the elasticity of a solid on the wetting process is taken into consideration.Scaling analysis is performed based on molecular kinetic theory and validated by our simulations.Our results may expand our knowledge of wetting on pillars and assisting the future design of active control of wetting in practical applications.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Nonlinear Mechanics, Institute of Mechanics, Chinese Academy of Sciences, Beijing, People's Republic of China.

ABSTRACT
Dynamic wetting on the flexible hydrophilic pillar-arrays is studied using large scale molecular dynamics simulations. For the first time, the combined effect of the surface topology, the intrinsic wettability and the elasticity of a solid on the wetting process is taken into consideration. The direction-dependent dynamics of both liquid and pillars, especially at the moving contact line (MCL), is revealed at atomic level. The flexible pillars accelerate the liquid when the liquid approaches, and pin the liquid when the liquid passes. The liquid deforms the pillars, resulting energy dissipation at the MCL. Scaling analysis is performed based on molecular kinetic theory and validated by our simulations. Our results may expand our knowledge of wetting on pillars and assisting the future design of active control of wetting in practical applications.

Show MeSH
Related in: MedlinePlus