Multiscale exploration of microdroplet transport on fibers for optimized mass transfer

Abstract

Droplets exhibit distinct wetting characteristics and transport behavior on solid substrates at the macroscopic and microscopic scales. This behavior is critical for understanding liquid mass transfer on fibrous membranes. To better understand and control the mass transfer of liquids on fibrous membranes, we combined in situ visualization techniques with multiphase flow simulations. This approach enabled us to systematically explore the effects of various factors, including fiber wettability, fiber diameter, and fiber spacing, on liquid transfer behavior. Furthermore, we successfully elucidated the transfer mechanisms governing droplet transport on individual fibers and between adjacent fibers. Based on our findings, we constructed composite fiber membranes with varying fiber diameters and wettability structures. The validity of the proposed approach was verified by comparing fog collection, droplet wetting, and liquid permeation efficiency. Consequently, this study establishes a transferable cross-scale framework and proposes a general design strategy for constructing fibrous membranes tailored to diverse application requirements.

Graphical abstract

Keywords

microdroplets / nanofibers / in situ visualization / electrospinning / aerosol transport / asymmetric wettability

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