TY - JOUR
T1 - Viscoelastic wetting
T2 - Cox-Voinov theory with normal stress effects
AU - Kansal, Minkush
AU - Bertin, Vincent
AU - Datt, Charu
AU - Eggers, Jens
AU - Snoeijer, Jacco H.
N1 - Publisher Copyright:
© The Author(s), 2024. Published by Cambridge University Press.
PY - 2024/4/25
Y1 - 2024/4/25
N2 - The classical Cox-Voinov theory of contact line motion provides a relation between the macroscopically observable contact angle, and the microscopic wetting angle as a function of contact-line velocity. Here, we investigate how viscoelasticity, specifically the normal stress effect, modifies the wetting dynamics. Using the thin film equation for the second-order fluid, it is found that the normal stress effect is dominant at small scales yet can significantly affect macroscopic motion. We show that the effect can be incorporated in the Cox-Voinov theory through an apparent microscopic angle, which differs from the true microscopic angle. The theory is applied to the classical problems of drop spreading and dip coating, which shows how normal stress facilitates (inhibits) the motion of advancing (receding) contact lines. For rapid advancing motion, the apparent microscopic angle can tend to zero, in which case the dynamics is described by a regime that was already anticipated in Boudaoud (Eur. Phys. J. E, vol. 22, 2007, pp. 107-109).
AB - The classical Cox-Voinov theory of contact line motion provides a relation between the macroscopically observable contact angle, and the microscopic wetting angle as a function of contact-line velocity. Here, we investigate how viscoelasticity, specifically the normal stress effect, modifies the wetting dynamics. Using the thin film equation for the second-order fluid, it is found that the normal stress effect is dominant at small scales yet can significantly affect macroscopic motion. We show that the effect can be incorporated in the Cox-Voinov theory through an apparent microscopic angle, which differs from the true microscopic angle. The theory is applied to the classical problems of drop spreading and dip coating, which shows how normal stress facilitates (inhibits) the motion of advancing (receding) contact lines. For rapid advancing motion, the apparent microscopic angle can tend to zero, in which case the dynamics is described by a regime that was already anticipated in Boudaoud (Eur. Phys. J. E, vol. 22, 2007, pp. 107-109).
KW - UT-Hybrid-D
KW - drops
KW - viscoelasticity
KW - contact lines
UR - http://www.scopus.com/inward/record.url?scp=85190831862&partnerID=8YFLogxK
U2 - 10.1017/jfm.2024.296
DO - 10.1017/jfm.2024.296
M3 - Article
AN - SCOPUS:85190831862
SN - 0022-1120
VL - 985
JO - Journal of fluid mechanics
JF - Journal of fluid mechanics
M1 - A17
ER -