FESEM image of a gel prepared from nanofibrils linked with 1,800 g/mol PEI. Images acquired at relatively (A) low and (B) high magnifications. The image in (B) has been acquired from the area marked with a dotted rectangle in the image in (A). Note the nano-sized fibrils forming the network structure.
Syverud et al. Nanoscale Research Letters 2011 6:626 doi:10.1186/1556-276X-6-626