Smooth surfaces advancing/receding contact angles

Figure 4. Advancing and receding contact angles of water on smooth titanium metal coated glass (adv = rec = O) and silicon wafer (adv = A rec = a) surfaces as a function of the 0H-DDP04(NH4)2 concentration in the SAM-forming solution, expressed as a mole fraction, /0H-DDPO4 = [0H-DDP04(NH4)2]/ [0H-DDP04(NH4>2] + [DDP04(NH4>2]. ...

Table 1 Advancing and receding water contact angles, contact angle hysteresis and the surface energy values for smooth surfaces covered by PS and FPS and chemisorbed FSI...

The non-slip boundary condition is discussed in an excellent paper by Huh and Scriven They take note of the fact that, previous workers seem not to have been well informed by fluid mechanics , in aUuding to the essentially surface chemical analyses of spreading dynamics. Another point they address is that except for very smooth surfaces and non-adsorbing hquids the advancing or receding of the contact line proceeds in a slip-stick and discontinuous fashion a fact which is the focus of attention in current analyses of contact angle hysteresis using the theory of random fluctuations... 

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