Fig. 9: Schematic of the forces (drag force \({F}_{{{{{{\rm{H}}}}}}}\), adhesive force \({F}_{{{{{{\rm{A}}}}}}}\), friction force \({F}_{{{{{{\rm{F}}}}}}}\), and repulsive force \({F}_{{{{{{\rm{R}}}}}}}\)) acting on the hormone molecule.

A In an ideal case of VaCNT membrane with perfect cylindrical pores (note that the actual membrane is not as perfect), B In an actual VaCNT, C In an active layer of NF. D In a dense layer of UF. E In an MF. The pore and steroid hormone diameters are to scale; the pore lengths and pore diameters are not to scale; and the axial (\({F}_{{{{{{\rm{H}}}}}}}\) and \({F}_{{{{{{\rm{F}}}}}}}\)) and radial (\({F}_{{{{{{\rm{A}}}}}}}\) and \({F}_{{{{{{\rm{R}}}}}}}\)) forces are not to scale with each other.