Fig. 8.

SEM images of (a–c) cross-sections; and (d–f) top surface of three co-ES strips produced at the core flow rate of 0.8 mL/h, 1.4 mL/h and 2.0 mL/h; (g) cross-section of 1.4 mL/h fiber bundle; (h) longitudinal section of 1.4 mL/h fiber strip; (i–j) box-and-whisker plots representing pore size (d_n) and pore shape parameter (γ) against core flow rate. Median values, interquartile ranges (i.q.r.) and 1.5 times the i.q.r (excluding outliers ° and extreme values *) are denoted by horizontal bars, boxes and whiskers respectively. The changes in pore size and pore shape were significant with the increasing core flow rate (Kruskal–Wallis, p < 0.01).