Printable feedstocks that can produce lightweight, robust, and ductile structures with tunable and switchable conductivity are of considerable interest for numerous application spaces.

Commercially available solutions of polyaniline (PANI) stabilized with dinonylnaphthalene sulfonic acid (DNNSA) offer a convenient means of forming PANI films via solution casting that are of interest for energy storage and other electrochemical applications. Here, we study the electrochemical charge storage properties of 200–400 nm thick PANI films cast from PANI-DNNSA solutions before and after postprocessing steps. As-cast PANI-DNNSA films exhibit a specific capacitance of <20 F/g at a 50 mV/s sweep rate, which increases to >300 F/g after p-toluene sulfonic acid:butanol (pTSA:BuOH) and dibromopropane (PrBr2) treatments. Crosslinked PANI also exhibits a 25% improvement in capacity retention over un-crosslinked PANI after 500 charge/discharge cycles. The capacity, energy, and power of postprocessed PANI films is examined in a symmetric coin cell device, and the utility of soluble PANI is demonstrated by coating planar and porous substrates using spin coating, drop casting, and dip coating techniques. These studies inform the use of PANI-DNNSA to fabricate high-capacity electrochemical devices.

Conductive polyaniline (PANI) coatings find application in various fields, such as electrostatic dissipation, anticorrosion coatings, actives delivery, batteries, and solar control. Improving the thermal and electrical stability of PANI coatings at high temperatures and challenging environments is of growing interest. In this study, a novel polymer blend formulation was developed by adding polyurethane (PU) and sulfonyldiphenol (SDP) to a dinonylnaphthalene sulfonic acid (DNNSA)-doped PANI matrix. Films of the PANI-PU/SDP formulation and unmodified PANI control films were prepared on ITO glass substrates using spin coating, followed by thermal treatment. Characterization of the films was performed using thermogravimetric analysis-mass spectrometry (TGA-MS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS) with depth profiling. Results showed that unmodified PANI films aged at 150 degrees C exhibited rapid thermo-oxidative degradation, resulting in a significant loss in electrical conductivity after 24 h. The inclusion of PU and SDP remarkably improved the thermal stability of the films, maintaining desirable conductivity levels over a week. ToF-SIMS depth profiling helped identify potential degradation mechanisms and monitor changes in chemical composition throughout the film thickness. This study provides insights into the functionality, optimization, and deployment of these new film types.

Secondary dopants and the doping methods were identified for increasing the electrical conductivity of a highly processable and a primarily doped polyaniline dinonylnaphthalene sulfonic acid (PANI-DNNSA). The secondary doping was carried out using film, solution, and vapor doping methods. The doping methods and functional groups of secondary dopants were observed to play a critical role for inducing electrical characteristics of polyaniline. When secondary film doping method and p-toluenesulfonic acid were used, the electrical conductivity of the secondary doped polyaniline was measured to be increased from 0.16 to 334 S/cm. A novel vapor annealing doping method was developed to incorporate secondary dopants into solution cast polyaniline films.

Historically, the aerospace industry has driven major developments in polymer and material science. Technology has evolved from wood and coated fabric to metals to advanced polymer composite systems in response to demands of both the commercial and defense aerospace industries. Future systems will require event more advanced technologies such as those afforded by electroactive and conductive polymers (EAPs). The unique properties of these materials provide the ability to construct intelligent systems which produce a defined, predictable response to an input. For example, as a corrosion protection coating, an EAP would sense corrosion at the molecular level and release a corrosion inhibitor before major damage could occur. A self-detoxifying system would sense a toxin and respond by releasing bactericide to kill it. As depicted below, material advancements being sought for future aerospace systems include: Controllable optical absorption and emission across a wide spectral range Tunable conductivity from 10-5 to >10,0000 S/cm for antistatic and shielding Controlled, on demand release of active molecules for self-repair, detoxification and corrosion protection High power energy storage and capture This presentation will explore some of the issues involved with developing and transitioning EAP technology into current and future aerospace products.

Changing environmental regulations, market needs, and materials of construction continuously drive the evolution of aerospace coatings and application processes. Boeing actively pursues a continuous improvement strategy for its products to meet these changing demands. This strategy is based on extensive internal R&D programs as well as significant collaborations with suppliers, universities, as well as small and large businesses. This paper will review some challenges involved in developing new, more environmentally friendly coatings and will focus on current approaches to eliminate hexavalent chromium in future coating systems and processes.

Performance evaluation of non-chromium corrosion inhibiting compounds incorporated into aerospace epoxy primers is a challenge. There is a lack of correlation between efficient analytical techniques and industry standard tests such as ASTM B 117 and in-service data. The goal of this project is to develop screening tools for characterization of corrosion inhibitor performance in a polymer matrix.Results will be presented showing the use of laser microscopy and optical interferometery imaging techniques to correlate pit morphology on coated 2XXX and 7XXX series aerospace aluminum alloys to corrosion inhibiting coating performance. In addition, a novel method will be introduced to track the retention of coating corrosion inhibiting properties over time.

Growing environmental concerns regarding the use of heavy metals in coating formulations have led to a new coating strategy using inherently conducting polymers (ICP), such as polyaniline (PANI). as a key component. The principal potential advantage offered by the ICP coating technology is toleration of pinholes and minor scratches. This paper introduces the use of new PANI formulations that are doped with phosphoric acids. Salt fog exposure tests point to phosphoric acid salts of PANI being more effective for corrosion protection than traditionally used sulfonic acid salts. Scanning reference electrode technology (SRET) data support the salt fog results in that the sulfonic acid dopants exhibited an increasing galvanic activity with time while the phosphonic acid dopants, showed a decrease in activity with time, indicating passivation. A qualitative model is proposed which entails passivation of the metal surface through anodization of the metal by PANI and formation of an insoluble iron-dopant salt at the metal surface.