Preparation of ion-exchange fiber fabrics by electrospray deposition

Ion-exchange fiber (IEF) fabrics were prepared by electrospray deposition (ESD) and post-deposition chemical modification of their surfaces. Nonwoven fibrous fabrics were obtained from the solutions of synthetic polymers—polystyrene (PS) and poly(4-vinylpyridine) (P4VP)—of various concentrations. The diameter of the fiber in the fabrics ranged from 600 nm to 1.70 μm. Cation- and anion-exchange fiber (CEF and AEF) fabrics were obtained from the sulfonation of PS fabrics and the quaternization of P4VP fabrics, respectively. These fabrics were thoroughly characterized by a series of techniques, such as scanning electron microscopy (SEM), permporometry, nitrogen adsorption measurements, and potentiometric titrations. The SEM images showed that the fabrics had a porous structure after their chemical modification. The mean pore size, porosity, and specific surface area of the flow-through pores were 1.67–3.53 μm, about 80%, and 13 m2/g, respectively. The ion-exchange capacity was in the range from 0.78 to 1.34 mmol/g. The AEF fabric, on the other hand, showed a high specific surface area, i.e., the Brunauer–Emmett–Teller (BET) surface area of 600 m2/g, due to the formation of much smaller pores on the surface of the fiber structure in the fabric. The secondary chemical modification of the nano-microfiber fabrics by ESD provides novel functional materials with a large adsorption capacity and a high catalytic activity.

Graphical abstractIon-exchange fiber fabrics were prepared by electrospray deposition from the solutions of synthetic polymers, polystyrene (PS) and poly(4-vinylpyridine) (P4VP), and post-deposition chemical modification of their surfaces.Figure optionsDownload full-size imageDownload as PowerPoint slide