Application of nanofibrous mats is not restricted only to technical products such as filters, sensors, and battery separators, but they are widely used also in medicine (preparation of artificial organs, vascular transplants, targeted drug supply). The dominant characteristic of nanofibres is their extremely high ratio relating their surface and occupied volume. The nanofibres diameters range from units of nanometres up to micrometres. At present, an application of nanotechnologies for a production of membranes and filters based on nanofibrous mats is absolutely essential in a series of industrial branches. Owing to high specific surface and permeability, the nanofibrous membranes exhibit high filtration efficiency, enable higher throughput, demonstrate strong chemical resistivity, exhibit remarkable absorption capacity, and also can be used for temporary trapping of functional groups or biochemical materials. Nanofibrous mats are also used for filtering drinking water from geothermal sources and in the process of desalination.
Synthetic or natural polymer, mostly in a form of polymer solution or polymer melt, represents a primary source for nanofibres production. An electrospinning device is composed of three basic components: a spinnable electrode (a metal stick, a needle or a drum), a collector (static or revolving) and a high-voltage power supply. Polymer solution surface is disturbed by exerting higher voltage (10–70 kV) under an absence of any mechanical impetus. Surface is covered by so called Taylor's cones from which the nanofibres are emitted towards the grounded collector. The polymer jets directed towards the collector are elongated under simultaneous solvent evaporation. Consequently, the solid fibres impact on the collector either randomly or ordered with respect to a collector arrangement.
This manufacturing process is influenced by a number of factors, especially by the material parameters (properties of polymers and solvents participating in polymer solutions) and the process parameters (electric voltage, a tip-to-collector distance, temperature, humidity). One of the most important parameters for a creation of nanofibres is represented by rheological behaviour of polymer solutions, specifically viscosity and viscoelasticity substantially participating in creation and quality of nanofibrous mats (including nanofibres diameters). Rheological properties of polymer solutions can be significantly adapted by an addition of nanoparticles of active materials (hydrophobic, hydrophilic, antibacterial, magnetic). Viscosity (flow resistance) of polymer solutions influences not only initialization of the electrospinning process but also a diameter of the resulting nanofibres. Viscoelasticity of a polymer solution contributes both to jet forming during elongation and to a deposition of nanofibres on a collector.
The institutional research aims at elucidation of interplay between flow properties of polymer solutions (an interaction polymer-solvent-nanoparticles) and morphology of nanofibres (a shape and diameter of nanofibers) produced by the process of electrospinning. Rheological approach enables to predict e.g. nanofibres diameters and thus to replace an often used trial-and-error method which is time consuming and expensive. Among other things the rheological methods can also determine the materials a priori unsuitable for the process of electrospinning.
Filip, P., Zelenková, J., Peer, P. (2020). Evaluation of an onset of electrospun beadless poly(ethylene oxide) nanofibres. Journal of Applied Polymer Science (accepted)
Peer, P., Cvek. M., Urbánek. M., Sedlačík, M. (2020). Preparation of electrospun magnetic polyvinyl butyral/Fe(2)O(3)nanofibrous membranes for effective removal of iron ions from groundwater. Journal of Applied Polymer Science (in press)
Filip, P., Peer, P. (2019). Characterization of poly(ethylene oxide) nanofibres - mutual relations between mean diameter of electrospun nanofibres and solution characteristics. Processes 7(12), 948.
Peer, P., Polášková, M., Musilová, L. (2019). Superhydrophobic poly(vinyl butyral) nanofibrous membrane containing various silica nanoparticles. Journal of the Textile Institute 110(10), 1508-1514.
Polášková, M. , Peer, P., Čermák, R., Ponížil, P. (2019). Effect of thermal treatment on crystallinity of poly(ethylene oxide) electrospun fibers. Polymers 11(9), 1384.
Peer, P., Polášková, M., Šuly, P. (2018). Rheology of Polyvinyl Butyral Solution Containing Fumed Silica in Correlation with Electrospinning. Chinese Journal Of Polymer Science 36(6), 742-748.
Sedlaříková, J., Doležalová, M., Egner, P., Pavlačková, J., Krejčí, J., Rudolf, O., Peer, P., (2017). Effect of oregano and marjoram essential oils on the physical and antimicrobial properties of chitosan based systems. International Journal Of Polymer Science 2017, Article ID 2593863.
Peer, P., Filip, P., (2017). Nanofibrous web quality in dependence on the preparation of poly(ethylene oxide) aqueous solutions. The Journal of The Textile Institute 108(12), 2021-2026.
Peer, P., Filip, P., Polášková, M., Kucharczyk, P., Pavlínek, V., (2016). The influence of sonication of poly(ethylene oxide) solutions to the quality of resulting electrospun nanofibrous mats. Polymer Degradation And Stability 126, 101-106.