Journal of the Korean Society of Visualization (한국가시화정보학회지)

The Korean Society of Visualization (한국가시화정보학회)
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Measurement of Dynamic Contact Angle of Droplet on Moving Hydrophobic and Hydrophilic Surfaces

이동하는 소수성 및 친수성 표면에서 액적의 동접촉각 측정

  • Received : 2018.07.12
  • Accepted : 2018.08.20
  • Published : 2018.08.31
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Abstract

This study investigates dynamic wetting behaviors of a water droplet placed on surfaces with different wettability and nano-structures. Hydrophobic and hydrophilic properties on as-received silicon wafers were prepared by fabricating thin films of hydrophobic polymer and hydrophilic nanoparticles via layer-by-layer coating. Dynamic advancing contact angle of droplets on the prepared surfaces was measured at various moving velocities of triple contact line with a high-speed video camera. As advancing velocity of triple contact line increased, dynamic advancing contact angle on the as-received silicon and hydrophobic surfaces sharply increased up to $80^{\circ}$ in the range of order of mm/sec whereas the SiO2 nanoparticle-coated hydrophilic surface maintained low contact angles of about $30^{\circ}$ and then it gradually increased in the velocity range of order of hundred mm/sec. The improved dynamic wetting ability observed on the nanostructured hydrophilic surface can benefit the performance of various phase-change heat transfer phenomena under forced convective flow.

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References

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