Superhydrophilic surfaces contact angle

Furthermore, titanium oxide thin films have been found to exhibit a unique and useful function (i.e., a superhydrophilic property). Usually, the contact angle of a water droplet on a surface is 50 -70° therefore, metal oxide surfaces become cloudy when water is dropped on them or if there is moisture in the atmosphere. However, under UV light irradiation of the titanium oxide surfaces, this contact angle of water droplets becomes smaller, even reaching zero (superhydrophil-icity), its extent depending on the UV irradiation time and irradiation intensity. Thus, under UV light irradiation, titanium oxide thin-film surfaces never become... 

Such structured film shows different wettability from a normal silica film. Figure 4 shows the shape of a water droplet and corresponding contact angles on the silica nano-structured porous film (shown in Fig. 2) before and after surface modification. When a water droplet is deposited on the fresh silica ordered pore array, it spreads out rapidly on surface of the sample, which shows superhydrophilicity with... 

Wetting H-terminated wires superhydrophobic (>135°) Oxidized wires are superhydrophilic (<5°) Contact-angle dependence on wire density, diameter, length Surface coatings Wang et al. (2012)... 

Keywords Bubble, superhydrophilic surface, sliding angle, contact angle hysteresis, adhesion force... 

When the substrates were titled, the captive air bubble sitting on the superhydrophilic surface moved and slid up more easily at a lower sliding angle than on a hydrophilic surface. For example, Figure 6.5 shows the profiles of the air bubbles of the same volume (20 pL) on the hydrophilic and superhydrophilic surfaces, at both the initial horizontal position and the inclination at a sliding angle. When an air bubble sits on the micropillared superhydrophilic surface immersed in water, there is no direct contact between the bottom trench of the micropillared solid surface and... 

Figure 6.5 (a-b) Profiles of air bubbles on hydrophilic and superhydrophilic surfaces, respectively, in a horizontal position after stabilization, (c-d) Deformation of the air bubble at inclination (at sliding angle) and the change in contact angles. On the hydrophilic surface (c), the air bubble (20 pL) started to slide up at 13 with the maximum/minimum contact angles of 145 and 124 , respectively. On the... 

Figure 6.6d shows the experimentally measured sliding angles with varying bubble volume. As can be expected from Equation (6.7), the sliding angle on the superhydrophilic surface is much lower than that on the hydrophilic surface due to the lower contact angle hysteresis (CAH) or... 

Surfaces that possess water contact angles less than 5° within 1 second of drop deposition are called superhydrophilic surfaces. Materials with superhydrophilic surfaces have the highest water wetting property [4-6]. Surfaces that exhibit water contact angles of greater than 150° are called superhydrophobic surfaces [3,7]. 

The stability of the surface wettability was studied by measuring the water contact angles at 24 h., 72 h., and 144 h. after the plasma treatment. There was a general increase in the water contact angle as a function of time after the plasma treatment. The rate of increase in the water contact angle as a function of time after the plasma treatment for the superhydrophilic surfaces was found to be significantly smaller (p < 0.05) than the hydrophilic surfaces (6 < 10°). 

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