Conductive polymer ultrafine fibers via electrospinning: Preparation, physical properties and applications

Conductive polymers (CPs) are promising organic semiconductors for many essential applications because of their tunable physical/chemical properties, mechanical flexibility, low weight, reversible doping, good biocompatibility, and scalable production. However, CPs have not achieved their expected application potential in conventional processing methods. Electrospinning is a simple and highly versatile technique that can be used for mass fabrication of continuous ultrafine fibers from various polymers and composites. Electrospun fibers have many advantages, including uniformity, porosity, large surface areas, and mechanical strength, which present new application areas of CPs, and solve a number of problems related to the applicability of the polymers. However, as CPs are soluble and brittle, electrospinning requires a specific strategy. Different approaches, including direct electrospinning of CPs into fibers, co-electrospinning of blends of CPs and other spinnable carrier polymers, and synthesizing of electrospun fiber-template, have been developed to solve this problem. In this review, the recent achievements of fabricating CP-based ultrafine fibers using an electrospinning process are summarized, along with the characterization of their physical–chemical properties, such as electrical conductivity, wettability, and mechanical and thermal properties, which are further improved by modification. More emphasis is placed on the potential applications of electrospun CP ultrafine fibers in bio-/chemical sensors, artificial muscles, neural electrodes/interfaces, tissue regeneration, controlled drug release, flexible/stretchable electronic devices, energy storage, and electromagnetic interference shielding materials. Furthermore, the current challenges and future opportunities are also addressed.