Hierarchical nanostructured conducting polymer hydrogel with high electrochemical activity

Abstract

Conducting polymer hydrogels represent a unique class of materials that synergizes the advantageous features of hydrogels and organic conductors and have been used in many applications such as bioelectronics and energy storage devices. They are often synthesized by polymerizing conductive polymer monomer within a nonconducting hydrogel matrix, resulting in deterioration of their electrical properties. Here, we report a scalable and versatile synthesis of multifunctional polyaniline (PAni) hydrogel with excellent electronic conductivity and electrochemical properties. With high surface area and three-dimensional porous nanostructures, the PAni hydrogels demonstrated potential as high-performance supercapacitor electrodes with high specific capacitance (∼480 F·g −1 ), unprecedented rate capability, and cycling stability (∼83% capacitance retention after 10,000 cycles). The PAni hydrogels can also function as the active component of glucose oxidase sensors with fast response time (∼0.3 s) and superior sensitivity (∼16.7 μA·mM −1 ). The scalable synthesis and excellent electrode performance of the PAni hydrogel make it an attractive candidate for bioelectronics and future-generation energy storage electrodes.conductive polymer hydrogel | supercapacitors | biosensors H ydrogels are polymeric networks that have a high level of hydration and three-dimensional (3D) microstructures bearing similarities to natural tissues (1, 2). Hydrogels based on conducting polymers [e.g., polythiophene, polyaniline (PAni), and polypyrrole] combine the unique properties of hydrogels with the electrical and optical properties of metals or semiconductors (3-6) thus offering an array of features such as intrinsic 3D microstructured conducting frameworks that promote the transport of charges, ions, and molecules (7). Conducting polymer hydrogels provide an excellent interface between the electronictransporting phase (electrode) and the ionic-transporting phase (electrolyte), between biological and synthetic systems, as well as between soft and hard materials (8). As a result, conducting polymer hydrogels have demonstrated great potential for a broad range of applications from energy storage devices such as biofuel cells and supercapacitors, to molecular and bioelectronics (9) and medical electrodes (8).To date, the synthetic routes toward conducting polymer hydrogels include synthesizing a conducting polymer monomer within a nonconducting hydrogel matrix (8, 9) using multivalent metal ions (Fe 3þ or Mg 2þ ) to crosslink poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) (10, 11) and using nonconducting poly(ethylene glycol) diglycidyl ether, or poly(styrenesulfonate) to crosslink PAni (12, 13); however, nonconducting hydrogel matrix and polymers result in the deterioration of the electrical properties, whereas excessive metal ions may reduce the biocompatibility of hydrogels. Moreover, there have yet been any reports in regard to conductive hydrogels that can be facilely micropatterned, which is important for fabricating hy...

Nanostructured conductive polymers for advanced energy storage

“…7c and d). Recently, Yang et al 44 developed PPy and PTh polymers with a greatly enhanced redox capacity of 140 mA h g À1 and excellent cyclability by doping with Fe(CN) 6 4À anions which serve as counterion dopants to ensure electronic conduction of the polymer and function as redox mediators to facilitate the charge transfer between the polymer and electrolyte. Another strategy to improve the performance of conductive polymer-based electrodes is the development of nanostructured composites with carbon materials, such as graphene and carbon nanotubes.…”

Photolatently modulable hydrogels using unilamellar titania nanosheets as photocatalytic crosslinkers

“…W ith increasing demand for human-and environmentfriendly renewable materials, particular attention has been focused on hydrogels, a class of soft matter mainly composed of water [1][2][3][4][5][6] . Meanwhile, hydrogel materials, whose structures and functions are postmodulable multiple times, just like living tissues, have long been awaited [7][8][9][10] .…”

Nature-inspired thermo-responsive multifunctional membrane adaptively hybridized with PNIPAm and PPy

“…22,27 To improve the performance of CPs, a diverse set of architectures have been adopted and applied, because well-defined architectures are highly important in materials science, nanotechnology and bioengineering. 19,[28][29][30] However, direct and precise patterning of various architectures is still a major challenge because the conventional technologies that are used to produce designed polymers have poor reproducibility and involve multiple fabrication steps, which makes the process expensive, time-consuming and difficult to scale-up. 30 In this study, inspired by the functional features of plants, such as the bending of the pulvinus in M. pudica, the gating of stomata in leaf, and the selective filtering of the cellular membrane, a multifunctional hybrid membrane (HM) with thermo-responsive and conductive properties was adaptively synthesized with poly(N-isopropylacrylamide) (PNIPAm) and poly(pyrrole) (PPy), to enhance the functionalities of conventional CP hydrogels.…”

“…[13][14][15][16][17][18] For instance, conductive polymer (CP) hydrogels contain conjugated conductive backbones to promote charge transport and exhibit semiconducting electrical properties. 19 Thus, CP hydrogels have the distinctive properties of a hydrogel and the electrical properties of CPs. Their potential has been demonstrated in a broad range of applications, such as in energy conversion and storage devices, supercapacitors, sensors, bioelectronics and medical electrodes.…”