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Simultaneous SAXS-WAXD measurements are carried out to gain information about the microstructure and the molecular orientation developed by polymeric chains during the electrospinning process. Three semicrystalline polymers were studied, namely polyacrylonitrile, Nylon 6,6, and poly(ethylene oxide), as non-woven mats with either randomly arranged or aligned electrospun fibers. Mat thermal and morphological properties are investigated, together with their structural details in order to derive their hierarchical structure from the macro to the nano-scale. SAXS patterns have an elliptical shape with the main axis along the equator direction. No reflections are noticeable along the meridional direction, suggesting that the investigated electrospun fibers have a fibrillar structure with no trace of lamellar morphology. Combining the values of the unit cell and of the crystal size it can be concluded that in the fibers the ordered domains are organized into a bundle of fibrils due to the lateral aggregation of roughly 10 unit cells and the regular ordering of about either 50 (Nylon 6,6 and polyacrylonitrile) or 25 (poly(ethylene oxide)) cells in the chain direction.

Chapter 6 Increasing demand for access to clean and safe water around the globe emphasizes the development of new technologies for removing environmental pollutants. Especially, organic pollutants including dyes, volatile organic compounds (VOCs), polycyclic aromatic hydrocarbons (PAHs), pesticides, herbicides, and antibiotics prominently affect environmental health due to their hazardous nature. In the past several decades, advancements in electrospun fibrous membranes have resulted as an efficient filtering platform for removal of various pollutants in water, air, and soil. Electrospun nanofibers are efficient filters complementing their unique feature of accommodating a variety of functional molecules. The choice of material and the effect of experimental condition including pH, contact time, and adsorbent dosage on pollutant removal efficiency have been extensively reviewed previously. Our chapter focuses on recent progress in the developments of the electrospun functional nanofibrous composite membrane for various organic pollutants removal.

Chapter 13

Nowadays techniques for sensitive non-invasive, real-time monitoring of cell differentiation and maturation are highly demanded. In light of this, the development of electrochemical printed sensors impedance-based could represent a promising tool. In the present work, we developed 2D ink-jet printed sensors for myoblasts adhesion monitoring, using carbon-based ink on a substrate consisting in non-woven electrospun mats made in crosslinked poly(ε-caprolactone) (PCL). First of all, sensors printability was optimized and the biocompatibility tested. In order to determine the possibility to employ the prepared systems as scaffolds for dynamic cellular cultures, the mechanical response of the PCL scaffold was evaluated through the application of cyclic deformation tests. After that, electrical characterization of ink and substrate was performed, followed by electrochemical impedance-based measurements to evaluate myoblasts adhesion. Biocompatibility assessment showed good results for both carbon and PCL. Mechanical tests findings suggested that a training of 50 cycles and a proper value of strain should be applied before the cell seeding, in order to ensure a subsequent controlled strain amplitude. The sensorized scaffold allowed us to correlate cell adhesion with an increase of impedance module, in agreement with biocompatibility testing. Thus, this first preliminary testing suggested that this non-invasive impedance spectroscopy-based measurement system can be used for sensitive monitoring of cells adhesion, in static and moreover, as suggested from mechanical characterization, in dynamic conditions.