Abstract:
To investigate the effect of trapped gas and surface roughness, it is necessary to study
more deeply the hydrophobic nature of a material which has a different surface roughness value.
This research was conducted experimentally, by first preparing materials that have different grain
sizes. Then measuring contact angles, mapping surface roughness, and observing droplets when in
contact with the material. This study shows that the increase in droplet volume affects the contact
angle formed, the greater the droplet volume the droplet surface tension capability is getting
weaker. The smaller the grain size, the higher the contact angle formed, this is due to the particle
size that supports the droplet surface, when the particle size is small, the surface tension formed is
greater so that the droplet has a high contact angle. Micro/nano size bubbles that spread evenly on
the surface of hydrophobic material strongly support the occurrence of hydrophobic properties in a
material.
