Homogeneity of physical properties of electrospun gelatin nanofiber mats

Needleless electrospinning enables producing large-area nanofiber mats. As a previous study showed, however, the homogeneity of such large nanofibrous membranes regarding thickness and mass per unit area is relatively low. Here, the homogeneity of a gelatin nanofiber mat was investigated, electrospun by a Nanospider Lab from gelatin. Measurements of the mass per unit area, optical transmission, nanofiber diameter distribution and nanofiber orientation as well as surface roughness in various positions distributed over the nanofiber mat are reported. The results reveal that the homogeneity of the nanofiber mat cannot be evaluated by the optical appearance along the whole electrospun area, since especially the macroscopic parameters can vary even at positions of similar optical appearance. The paper thus suggests verifying all parameters reported in publications for the same area or at least adjacent areas to avoid reporting erroneous combinations of parameters, such as nanofiber morphology and membrane thickness for different areas.