Biopolymers and electrospinning techniques for the development of advanced applications

Over the last years electrospinning technique has emerged as an easy, fast and affordable approach to prepare nanofibrous membranes. Electrospinning is based on the application of a strong potential difference to create an electrically charged polymer solution jet which leads to the formation of nano and/or microfibres subsequently collected on a proper surface; thus, highly porous mats with a high specific surface area can be easily obtained. Several are the applications of the nanofibrous mats; with a micro-structure which strongly resemble the extra-cellular matrix they are found able to promote human cell viability and they can also be applied in other fields as the cleaning of artworks. Alginate, Agar, Agarose and Chitosan-based membranes are prepared via electrospinning using solutions and poly(ethylene oxide) or poly(vinyl alcohol) as co-spinning agents. Different solutions are rheologically characterized in order to assess the viscosity values suitable to proceed with the electrospinning process. The polymeric membranes are stabilized using different methods. A crosslinking approach is optimized to obtain insoluble mats whose composition is investigated, eventually proving the elimination of the co-spinning agent. Moreover, it is possible to prepare polysaccharide-based nanocomposite able to be electrospun in form of nanofibers for biomedical applications and food industry, obtaining antibacterial and antifungal mats for disinfection and prevention of biofilm formation thanks to the proprieties of nanoparticles, incorporating gold, silver and zinc oxide nanoparticles generated “in situ” through a bottom-up approach. Mechanical characterization is performed to test the stress/strain behaviour and, in order to increase the mechanical resistance of biopolymer membranes, a multilayer innovative nanostructured mat, ready to use, made with a layer of polycaprolactone (PCL) is prepared.