Quantitative characterization of the electrospun gelatin–chitosan nanofibers by coupling scanning electron microscopy and atomic force microscopy

Nanofibers were electrospun from gelatin and chitosan at different mass ratios (gelatin/chitosan: 0/100, 25/75, 50/50, 75/25, 100/0). Atomic force microscopy (AFM) combined with scanning electron microscopy (SEM) was utilized in this study to evaluate the morphological and mechanical properties of the gelatin–chitosan nanofibers. The SEM images showed that the electrospun gelatin–chitosan nanofibers possessed more uniform morphologies than the pure gelatin or chitosan nanofibers. Moreover, AFM-HarmoniX mode was used to quantitatively assess the Derjaguin–Müller–Toporov (DMT) modulus of gelatin–chitosan nanofibers. After modified by two correction factors, the DMT modulus of gelatin–chitosan nanofibers showed higher values than the pure gelatin or chitosan nanofibers, which indicated the existence of intermolecular interaction within the electrospun gelatin–chitosan nanofibers.