Preparation and moisture transport behavior of multilevel branching network nanofiber membrane: Based on the Lattice Boltzmann method and inspired by plant transpiration

Abstract

Ensuring the efficiency and safety of firefighters relies heavily on optimizing the moisture permeability of their suits. Inspired by the intricate multi-level network structure of plant transpiration, this study utilized electrospinning technology to prepare biomimetic vascular, veined multilevel branched network quick-drying nanofiber membranes. Combining X-ray microtomography (XMT) and the lattice Boltzmann method (LBM), this study conducted a 3D reconstruction of the microstructure of quick-drying nanofiber materials, establishing a characterization method for moisture permeability behavior from a micro to mesoscale perspective and conducted numerical simulations. The results indicate that in the nanofiber membrane, the fiber diameter and pore size between fibers gradually decrease from the inlet to the outlet in the forward flow direction (from PET side to PAN side). At the same displacement pressure difference, the average and maximum flow rates of forward percolation were significantly greater than reverse percolation (from PAN side to PET side); in the initial stage of forward percolation (x < 11), the flow rate first increased and then gradually decreased, with the rate of increase (k = 0.712623) significantly higher than the rate of decrease (k'=0.001102), while in reverse percolation, the flow rate continuously increased throughout the process; These phenomena are primarily due to different startup pressure gradients. Furthermore, the analysis of moisture transport performance indicates that the fiber membrane exhibits highly efficient unidirectional moisture transport capability. This study expands the understanding of the moisture permeability mechanism of nanofibers, which is significant for enhancing the protective performance and comfort of quick-drying firefighter fabrics.