Electrospinning of sacrificial nanofibres for the creation of nanochannels

All materials are subjected to physical damage, which will reduce their lifetime. In order to enhance the lifetime of manufactured goods, self-healing materials are being investigated.
In this project, a self-healing strategy will be developed based on a vascular approach. The channels serve as reservoir and distribution network to get the healing agent to the damaged site. A crack produced in the material would interrupt channel continuity and the healing agents will flow out in the matrix and react mending the defect. In this work, the vascular network is created by means of electrospinning of a Pullulan (natural water soluble polysaccharide) aqueous solution. Sub-micron fibres are created. The nanofibrous web is embedded in an epoxy matrix creating a composite. After the curing of the matrix, the nanochannels are created by dissolving the sacrificial nanofibres in water. It is very important to get beaded-free fibres of the right diameter in order to facilitate the infusion of the healing agents and their flow in the vascular network. Therefore, a study of the different diameters and fibre morphology that can be obtained via electrospinning has been carried out. The main parameter that has been changed was the concentration of Pullulan in the spinning solution. The average fibre diameter increases with the concentration of Pullulan in the solution.