Rapid Visualization of the Mass Distribution Profile of Electrospun Layers

Abstract

Nanofibrous materials are currently widely used in many different areas. One of the technologies commonly used for their production is electrospinning. The mass distribution in a produced nanofibrous layer is a crucial factor especially for filtration applications and active ingredients or drug release applications. Image analysis is an efficient non-destructive method of a mass distribution determination, which has already been used in the evaluation of textiles and melt-blown webs, but so far only a few publications have dealt with its use in the field of electrospun materials. To facilitate the process of image analysis of deposited nanofibers, we developed a new collector electrode, which makes it possible to determine the optical mass distribution profile of the produced layer. A series of experiments proved that the developed collector allows an easy evaluation of the appearance of nanofibrous layers as well as the effects of many associated factors such as emitter configuration on the resulting sample. The results showed how the properties of nanofibrous layers (such as deposition zone dimensions, location of these zones, mass distribution profiles produced by different spinning nozzles) can change during the electrospinning process. The advantages of the method described in the present article are that it allows a contactless and non-destructive determination of mass distribution, detection of macroscopic defects, and investigation of causes behind layer thickness inhomogeneities. All in all, the presented method is a useful research and development tool for the field of electrospinning.

The Effects of Electric Field Dynamics on the Quality of Large-Area Nanofibrous Layers

“…These initial experiments were evaluated visually and using image analysis tools. The image analysis was based on the fact that the pixel intensity of an image of a deposited layer photographed against light corresponds with the thickness of the layer [14,15]. Figure 4 shows images of layers deposited at different movement speeds of the moving body above the spinning electrode and of the belt.…”

“…The thickness homogeneity of a nanofibrous layer can be evaluated using several different methods. One method suitable for the evaluation of the thickness homogeneity of low-weight nanofibrous layers that cannot be removed from the substrate in one piece consists of analyzing the intensity of light passing through such a layer, or more precisely, in analyzing its absorption by the nanofibrous layer manifested in lower pixel intensities of its images in places of greater thickness [14]. This method allows researchers to quickly assess the thickness distribution across the layer; however, different pixel intensities are not correlated with local differences in area weight.…”