Fig. 4

SEM images of SFSTEX (panels a1/2), SFSTEX+HEX150/8 (panels b1/2), and SFSTEX+HEX190/4 (panels c1/2). The magnification was 250- (panels a/b/c-1) and 5000-fold (panel a/b/c-2)
SEM images of SFSTEX (panels a1/2), SFSTEX+HEX150/8 (panels b1/2), and SFSTEX+HEX190/4 (panels c1/2). The magnification was 250- (panels a/b/c-1) and 5000-fold (panel a/b/c-2)