Highly homogeneous core–sheath polyaniline nanofibers obtained by polymerisation on a wire-shaped template

Abstract

Defect-free and highly homogeneous polyaniline (PANI)-Nylon 6 electrospun nanofibers are obtained through a solvent-induced segregation of N-phenyl-1,4-phenylenediamine (ADPA) on a fiber surface followed by an oxidative surface polymerization onto a wire-shaped template. Different oxidation salts are tested both as additives of the spinning solutions and in a polymerization bath. Comparison between mats obtained with a solvent induced segregation process and classical feed solution electrospinning is highlighted. As a result, self-standing emeraldine base PANI (EB) membranes are produced both in this pristine state and in a doped emeraldine salt state (ES). The doping process is carried out in different acid baths, namely hydrochloric acid, sulfuric acid and p-toluene sulphonic acid, the last being the most effective. Wire-shaped PANI membranes are characterized by scanning electron microscopy (SEM) and the polymerization/doping states of PANI are monitored step by step by UV-vis reflectance spectroscopy, infrared spectroscopy (FTIR) and contact angle measurements (CA).

The relevance of extensional rheology on electrospinning: the polyamide/iron chloride case

“…Although this technique is rather easy to implement for most of synthetic polymers, the processing of conducting polymers is not straightforward, due to the relatively low solubility and the limited number of entanglements of these materials. A method to overcome this issue consists in the production of a polymer mat to act as template, where an in situ polymerization of monomers may occur [6,7]. This strategy has been exploited by Granato and co-workers [6] to obtain nanofibres with an insulating core and a conducting shell starting from a polyamide 6 (PA6) solution containing iron(III) chloride (FeCl3), which promotes the following polymerization of pyrrole vapours onto the fibre surface.…”

Recent advances in core/shell bicomponent fibers and nanofibers: A review

“…There are also some complex and hybrid methods for spinning of nano/micro fibers. In a recent work, Castagna et al . developed a highly homogeneous emeraldine salt polyaniline (PANI) nanofibrous membrane consisting of a Nylon 6 core and a PANI sheath through a solvent‐induced segregation of N ‐phenyl‐1,4‐phenylenediamine (ADPA) on a fiber surface followed by an oxidative surface polymerization onto a wire‐shaped template.…”

Conducting Electrospun Nanofibres: Monitoring of Iodine Doping of P3HT through Infrared (IRAV) and Raman (RaAV) Polaron Spectroscopic Features

“…An exception is provided by poly-para-phenylenevinylenes (PPVs), whose relatively flexible chains and high molecular weight allow for easy collection of fluorescent defect-free fibres [ 27 ]. Over the years, different strategies have been applied to overcome the issues related to the electrospinning of π-conjugated polymers: the surface polymerisation of the monomers onto electrospun polymer fibres [ 28 , 29 , 30 ], the coaxial electrospinning of the conjugated polymer with an outer spinnable polymer or solvent feed [ 12 , 13 , 16 , 31 , 32 ] , or the mixing of the conjugated polymer with a spinnable polymer in the starting solution, to assist the formation of fibres [ 18 , 33 , 34 ].…”