Water Vapor Permeability through PAN Nanofiber Mat with Varying Membrane-Like Areas

Abstract

Electrospinning can be used to create nanofiber mats from diverse polymers which can be used as filters etc. Depending on the spinning parameters, also nano-membranes, i.e. non-fibrous mats, can be produced as well as mixtures from both morphologies. The ratio of membrane to fibrous areas can be tailored by the distance between the high voltage electrode and substrate. Here the impact of the mat morphology on the water vapour permeability through polyacrylonitrile nanofiber mats with different membrane-like areas is shown, allowing for tailoring the permeability between 0.1 Pa · m²/W and more than 10 Pa · m²/W. In this way it is possible to create the finest filters as well as nearly impenetrable thin membranes with the same technology.

On the reliability of highly magnified micrographs for structural analysis in materials science

“…Although pure homopolymers usually result in very homogeneous, large-area nonwovens regardless of the type of electrospinning, the addition of further polymers, nanoparticles and other additives leads to increasingly heterogeneous micro and nanostructures 26 . The occurrence of so-called fiber beads, agglomerates, network structures and membranous regions can be observed 27 . Figure 1a,b depict TEM images with different magnifications, taken on a PAN/nickel ferrite nanofiber cross-section.…”

Magnetic Nanofiber Mats for Data Storage and Transfer

“…However, this cannot be realized in a one-step electrospinning process. The easiest approaches to realize a combination of nanofibers with a data storage opportunity by electrospinning are preparing either combinations of nanofiber mats with embedded nanomembranes, which can simply be realized by decreasing the distance between the high-voltage electrode of the electrospinning apparatus and the substrate on which the fibers are placed [30], or creating combinations of nanofiber mats with embedded beads, which happens automatically when the polymer solid content in the spinning solution is reduced, as compared to ideal values [31]. Here we report on the second method.…”

Electrospinning a Dye-Sensitized Solar Cell

“…Coating the nanofiber mat even with a thin PEDOT:PSS layer reduces the transmission further [31]. This indicates that while it is generally possible to prepare fully electrospun DSSCs, further research is necessary to improve the optical properties, especially the transmission through one of the electrodes, e.g., by preparing one electrode as a combination of nanofibrous mat and nanomembrane which is possible by tailoring the electrospinning parameters correspondingly [33].…”