Fig. 3. SEM images of (a and b) SEBS, (c and d) 20 wt% hBN/SEBS composite film, (e and f) 40 wt% hBN/SEBS composite film, (g and h) 60 wt% hBN/SEBS composite film, (i and j) 80 wt% hBN/SEBS composite film, (k and l) 95 wt% hBN/SEBS composite film; (a), (c), (e), (g), (i) and (k): surface morphologies; (b), (d), (f), (h), (j) and (l): cross-sectional morphologies.