Synthesis and characterization of a novel polyurethane/polypyrrole‐p‐toluenesulfonate (PU/PPy‐pTS) electroactive nanofibrous bending actuator

Abstract

Electroactive actuators based on conductive polymers currently have attracted a great deal of attention. In this study, a nanofibrous structure of polypyrrole (PPy) was used to fabricate an electroactive bending actuator. For this purpose, polyurethane/PPy (PU/PPy) nanofibrous bending actuator was fabricated through the combined use of electrospinning and in-situ chemical polymerization. The response surface methodology (RSM) was considered to find the optimal electrospinning conditions for producing PU nanofibers with the minimum diameter. The in-situ chemical polymerization method was then used to prepare a conductive layer of PPy on the surface of optimum electrospun nanofibers with p-toluenesulfonate (pTS) as the dopant. The coated nanofibers were used in the fabrication of PU/PPy-pTS nanofibrous bending actuator. The morphology and electrical, thermal, electrochemical, and electrochemomechanical properties of the fabricated actuator were investigated. By using optimum conditions of electrospinning, PU nanofibers were obtained with a diameter of 221 nm. The results showed that the produced PU/PPy-pTS nanofibers enjoy good thermal stability and have an electrical conductivity of about 276.34 S/cm. The obtained cyclic voltammetric and dynamo-voltammetric responses showed that the dominant mechanism of actuation in the fabricated PU/PPy-pTS nanofibrous actuator is the exchange of perchlorate anions with a partial exchange of lithium cations in 1M lithium perchlorate electrolyte solution. The fabricated actuator was capable of undergoing 141°r eversible angular displacement during a potential cycle. The results demonstrated that, given high porosity, large specific surface area, flexibility, and desirable electrical properties, PU/PPy nanofibrous electroactive actuator provides a lot of potential for developing artificial muscle applications.

Preparation of electrospun shape memory polyurethane fibers in optimized electrospinning conditions via response surface methodology

“…They found that the increase of feeding rate, from 20 to 75 mL/min, had a great effect on the fibers' diameter. Ebadi et al 18…”

Electrospun PGS/PCL nanofibers: From straight to sponge and spring‐like morphology

“…during an extended healing time in in-vivo. [59][60][61] The structure of AA 40,15 sample is very similar to that of porous interconnected sponge-like native bone ( Figure 6). Usually, such a porous scaffold for bone tissue engineering is produced by using various methods such as solvent casting-particle leaching process, gas foaming, freeze-drying and phase separation.…”

“…One of the most widely used methods for the production of polymeric nanofibers is electrospinning. 5 Generally, the nanofibers can be composed of one or two components (blend) and or can have more complex structures such as coaxial and triaxial core-sheath [6][7][8] and these structures are used in various fields such as sensors and electronic, [9][10][11] actuators, [12][13][14][15][16] ion absorbance, [17][18][19] air and fluid filtration, [20][21][22] wound dressing [23][24][25][26] and burn healing, 27 adhesive and nanocomposites. 28,29 The other two important areas of nanofibers applications are drug delivery and tissue engineering.…”

Conductive Electrospun Nanofiber Mats

“…Similarly, the same group coated PU nanofibers with a p-toluenesulfonate doped PPy layer, resulting in electrical conductivity of approximately 276 S/cm. These nanofiber mats could be used as bending actuators [44]. To prepare scaffolds for neural cell growth, Xu et al prepared poly(l-lactide acid)-PCL fibers and coated them electrochemically with chitosan and PPy, resulting in conductivities of approximately 1 S/m [45].…”