Kr. Willson et S. Garoff, EFFECT OF CHAIN TERMINATION CHEMISTRY AND MOLECULAR-WEIGHT ON DYNAMICWETTING OF POLYMER LIQUIDS, Colloids and surfaces. A, Physicochemical and engineering aspects, 89(2-3), 1994, pp. 263-268
The dynamic wetting behavior of methyl- and hydroxyl-terminated poly(d
imethylsiloxane) with a range of molecular weights and viscosities is
discussed. Direct imaging of the fluid/air interface within 20 mum of
the contact line was used to probe this behavior. Models which account
for the unique hydrodynamics near a moving contact line accurately de
scribe the measured interface shapes. Our measurements provide a geome
try-independent characterization of the dynamic contact angle and thus
may be transferred to any macroscopic geometry. The dynamic wetting b
ehavior is more sensitive to the chain termination chemistry than to t
he variations in molecular weight and viscosity. Implications for the
unique hydrodynamics occurring near the contact line and governing the
spreading are explored.