Pore Size Distribution
With the microfibers providing the strength and structure, the nanofibers are free to fill in all the holes, giving a very narrow pore size distribution, as can be seen in the plot on the left. The full-width-at-half-max, a measure of the width of the distribution, is only about 10%, or about 40 nanometers. This allows Dreamweaver battery separators to be exceptionally good barriers while still maintaining about 70% porosity, for good ionic flow.