Contract angle measurement, surface

Profilometer and Contract Angle Measurements The copper surface after Pumice treatment was also examined by profilometry and characterized by contact angle measurement. The profilometer was supplied by Sheffield Measurement Division of Dayton, Ohio. The contact angle measurements were made using a microscope device supplied by Gilmont Instruments, Great Neck, New York. 

Cansoy CE (2014) The effect of drop size on contract angle measurements of superhydrophobic surfaces. RSC Adv 4 1197-1203... 

Fig. 2.18 Advancing and receding contact angle measurement for water droplets on (a) Teflon coated silicon and (b) AKD polymer surfaces with the drop expansion/contraction technique (Reproduced with permission from [45], Copyright 2008 Elsevier)...

The receding contact angle, Q can be measured when a previously formed sessile drop on the substrate surface is contracted by applying a suction of the drop liquid through... 

In measuring hysteresis, two techniques for approaching the maximum and minimum contact angles were attempted. Once a bubble was formed on a plate it could be expanded or contracted until the base moved and measurements could be taken. Alternatively the bubble volume could be slowly increased or decreased and measurements taken until movement occurred. Both methods produced similar results but, when differences occurred, the greater level of hysteresis was associated with the latter procedure, owing probably to the duration necessary to complete the movement of the wetting phase along the solid surface. 

---