Physical principles of electrospinning (Electrospinning as a nano-scale technology of the twenty-first century)

The history of electrospinning is briefly introduced at the beginning of the article. The fundaments of the process are then analysed physically to be translated into a successful technology. Self-organisation of fluid in electrospinning is perceived as a consequence of various instabilities, based on electrohydrodynamics and, thus, highlighted as a key factor, theorising the subject successfully to elevate it to a highly productive technology to manufacture nano-scale materials. The main physical principle of the self-organisation is appearance of unstable tiny capillary waves on liquid surfaces, either on a free liquid surface or on that confined in a capillary, which is influenced by external fields. The jet path is described, as well as its possible control, by special collectors and spinning electrodes. Two electrospinning variants, i.e. melt and core–shell electrospinning, are discussed in detail. Two scarcely referred exceptional features of electrospinning, electric wind and accompanying irradiations, are introduced in in-depth detail. Lastly, care is taken over the quality of polymeric solutions for electrospinning from the standpoint of Hansen solubility parameters and entanglements among polymeric chains.