Marangoni Contraction of Evaporating Sessile Droplets of Binary Mixtures.

ABSTRACT: The Marangoni contraction of sessile drops of a binary mixture of a volatile and a nonvolatile liquid has been investigated experimentally and theoretically. The origin of the contraction is the locally inhomogeneous evaporation rate of sessile drops. This leads to surface tension gradients and thus to a Marangoni flow. Simulations show that the interplay of Marangoni flow, capillary flow, diffusive transport, and evaporative losses can establish a quasistationary drop profile with an apparent nonzero contact angle even if both liquid components individually wet the substrate completely. Experiments with different solvents, initial mass fractions, and gaseous environments reveal a previously unknown universal power-law relation between the apparent contact angle and the relative undersatur

SUBMITTER: Karpitschka S 

PROVIDER: S-EPMC5645759 | biostudies-literature | 2017 May

REPOSITORIES: biostudies-literature