The performance and physical attributes of a material and product can be tailored to so far unmatched material strengths and properties by creating new nano fibrous structures from polymers by electrospinning. The electrospinning process uses an electric field to produce charged jets of polymer solutions or melts. Bending instabilities of the jet, caused by the surface charge, lead to extremely high local extension rates of the jet and produce fibres with diameters of the order of a few nanometer that consist of highly aligned polymer strands. However, the biggest unsolved problem of the electrospinning process is the sensitive equilibrium between surface tension, viscosity, elasticity and conductivity of the polymer solutions. These are controlled by molecular parameters as the molar mass, chemical microstructure, conformation in solution or supramolecular structures via intermolecular interactions. The optimal combination of these parameters is, as yet, unknown. Within this project, a novel and unique technical platform will be developed and installed, that is generally capable to image and analyse high speed free surface flows in miniaturised dimensions. This platform will then be utilized to analyse electrospinning process parameters and to connect them to the material properties and the molecular structure of the polymer solution. Only such a fundamental understanding of the relation of these properties to the flow and mass transfer phenomena on the micro-time and -dimensional scale will allow to design in the second part of this project the required structural and material properties of nano-scale fibres for: -novel fibre/matrix composites for the creation of ultra-high-strength hydrogel membranes; -short fibre morphologies created by a novel controlled disruptive spinning process at the boundaries of the parameter space; -tailoring of fibre properties from renewable resources by modification of the chemical side-chain structure of polysaccharides.
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