Digital light processing (DLP)-type 3D printing ensures several advantages, such as an easy solution process, a short printing time, high-quality printing, and selective light curing. Furthermore, polyurethane (PU) is among the promising candidates for 3D printing because of its wide range of applications. This work reports comparative studies on the fabrication and optimization of PU composites using a polyaniline (PANI) nanomaterial and a graphene sheet (GS) for DLP-type 3D printing. The morphologies and dispersion of the printed PU composites were studied by field emission scanning electron microscope (FE-SEM) images. Bonding structures in the PU composites were investigated by Fourier-transform infrared (FT-IR) spectroscopy. As-prepared PU/PANI and PU/GS composites with different filler contents were successfully printed into sculptures with different sizes and shapes. The PU/PANI and PU/GS composites exhibit the improved sheet resistance, which is up to 8.57 × 104 times (1.19 × 106 ohm/sq) lower and 1.27 × 105 times (8.05 × 105 ohm/sq) lower, respectively, than the pristine PU (1.02 × 1011 ohm/sq). Moreover, the PU/PANI and PU/GS composites demonstrate 1.41 times (44.5 MPa) higher and 2.19 times (69.3 MPa) higher tensile strengths compared with the pristine PU (31.6 MPa). This work suggests the potential uses of highly conductive PU composites for DLP-type 3D printing.

Solution-processable conducting polymers (CPs) are an effective means for producing thin-film electrodes with tunable thickness, and excellent electrical, electrochemical, and optical properties. Especially, solution-processable polyaniline (PANI) composites have drawn a great deal of interest due to of their ease of film-forming, high conductivity up to 103 S/cm, excellent redox behaviors, processability, and scalability. In this review, basic principles, fabrication methods, and applications of solution-processable PANI composites will be discussed. In addition, recent researches on the PANI-based electrodes for solar cells (SCs), electrochromic (EC) windows, thermoelectric (TE) materials, supercapacitors, sensors, antennas, electromagnetic interference (EMI) shielding, organic field-effect transistors (OFETs), and anti-corrosion coatings will be discussed. The presented examples in this review will offer new insights in the design and fabrication of high-performance electrodes from the PANI composite solutions for the development of thin-film electrodes for state-of-art applications.

Electroactive polymer hydrogel offers several advantages for electrical devices, including straightforward synthesis, high conductivity, excellent redox behavior, structural robustness, and outstanding mechanical properties. Here, we report an efficient strategy for generating polyvinyl alcohol–polyaniline–multilayer graphene hydrogels (PVA–PANI–MLG HDGs) with excellent scalability and significantly improved mechanical, electrical, and electrochemical properties; the hydrogels were then utilized in coin cell supercapacitors. Production can proceed through the simple formation of boronate (–O–B–O–) bonds between PANI and PVA chains; strong intermolecular interactions between MLG, PANI, and PVA chains contribute to stronger and more rigid HDGs. We identified the optimal amount of PVA (5 wt.%) that produces a nanofiber-like PVA–PANI HDG with better charge transport properties than PANI HDGs produced by earlier approaches. The PVA–PANI–MLG HDG demonstrated superior tensile strength (8.10 MPa) and higher specific capacitance (498.9 F/cm2, 166.3 F/cm3, and 304.0 F/g) than PVA–PANI HDGs without MLG. The remarkable reliability of the PVA–PANI–MLG HDG was demonstrated by 92.6% retention after 3000 cycles of galvanostatic charge–discharge. The advantages of this HDG mean that a coin cell supercapacitor assembled using it is a promising energy storage device for mobile and miniaturized electronics.