The receding contact angle

Hydrophobic/superhydrophobic oxidized metal surfaces showing negligible contact angle hysteresis

“…Besides such monofunctional silanes, it has been reported that alkylmethydichlorosilanes (RMeSiCl 2 , R = CH 3 , C 4 H 9 and C 6 H 13 ) form oligomeric layers from the vapor phase that effectively shield the surface, resulting in low contact angle hysteresis (water and n-hexadecane h A /h R values reported were 104°/103°and 36°/ 34°, 106°/104°and 18°/14°, and 104°/101°and 15°/10°, respectively) [11]. In another paper, the water h A /h R values of glass treated with a vapor of (Me) 2 SiCl 2 were reported to be 110°/107.5° [12]. Besides conventional Si SiO 2 and glass surfaces, one of the authors has recently reported that oxidized aluminum surfaces covered with a branchstructured monolayer of bis ((tridecafluoro-1 h A /h R values were 110°/109°and 52°/50°, respectively).…”

Advancing contact lines on chemically patterned surfaces

“…(11) does not fit the experimental points. Numerous studies [20][21][22][23][24] relate experimental apparent contact angles to Eq. (11).…”

Picoliter Water Contact Angle Measurement on Polymers

“…5 When the contact angle is estimated by fitting a function to the profile of a droplet, shape distortion by gravity must also be taken into account for larger droplets. 6 The sessile drop method of CA measurement commonly utilizes a few microliters of a liquid (e.g., ∼2 µL giving a 2 mm base diameter when CA ) 90°), which are placed on a surface from a needle. This method is useful for relatively large, homogeneous surfaces but lacks lateral resolution when analyzing surfaces with chemical differences on the submillimeter scale, as a result of the dimension of the base diameter of a droplet.…”