Molecular Interactions in Electrospinning: From Polymer Mixtures to Supramolecular Assemblies

Electrospinning is growing as a production technology for many applications, particularly in membranes and tissue engineering. One challenge in electrospinning is the need for high molecular weight polymers, a requirement that often prevents formation of fibers with high proportions of functional materials that may include particles, surfactants, cells, etc. Molecular interactions between lower molecular weight polymers or molecules can provide similar cohesion in the electrospinning jet as entanglements from high molecular weight polymers. This review covers the existing studies of molecular interactions in electrospinning, providing a comprehensive analysis of the different approaches and outlook for the future. Three major categories are discussed: polymer–polymer molecular interactions (such as electrospinning of coacervates or interacting polymer blends), polymer–small molecule interactions (including cross-linking agents or particles mixed with the polymer), and supramolecular polymer electrospinning (cycodextrins, micelles, etc.). Significant attention is paid to the rheology of the polymer solutions and the electrospinning phase diagrams as well as to how these advances expand the use of electrospinning for target applications.