Unraveling the spontaneous advancement of precursor films from a liquid reservoir to an isolated wall
Journal
Journal of Colloid and Interface Science
Journal Volume
710
Start Page
140007
ISSN
00219797
Date Issued
2026-05-15
Author(s)
Abstract
Hypothesis: Although the spreading of precursor films associated with total wetting liquids can be observed in droplet wetting or capillary flow, concurrent variations in evolving meniscus shape and transient Laplace pressure complicate the direct observation of the precursor film dynamics. To overcome this challenge, the present study employs a configuration that allows the liquid source to stabilize at the entrance, enabling the advancement of the precursor film to be exclusively monitored and analyzed under a constant driving force. Methods: The spontaneous advancement of precursor films, leaking from a reservoir to an isolated wall, is investigated using many-body dissipative particle dynamics simulations. The influences of surface wettability and the entrance width on the precursor film dynamics are systematically quantified. Findings: The advancing precursor film exhibits diffusion-like behavior, where the propagation length scales with t1/2. The spreading rate is governed by the interplay between the driving forces, characterized by the spreading coefficient (S) and entrance width (N), and the resistive wall friction. Specifically, the spreading rate increases with S at low wettability but eventually saturates. This saturation suggests that the increase in driving forces is effectively offset by the rising wall friction. Furthermore, widening the entrance facilitates faster spreading by reducing the Laplace pressure.
Subjects
Laplace pressure
Many-body dissipative particle dynamics
Precursor film
Spreading coefficient
Total wetting liquid
Publisher
Academic Press Inc.
Type
journal article