Humidity-independent conducting polyaniline films synthesized using advanced atmospheric pressure plasma polymerization with in-situ iodine doping

Abstract

This study reports on the synthesis and characterization of conducting polyaniline (PANI) thin films when using advanced atmospheric pressure plasma jets (APPJs). A simple method for synthesizing conducting polymers (CPs) with humidity-independent characteristics is introduced using advanced APPJs and an in-situ iodine doping method. In the case of ex-situ I 2 doping, a humidity effect study showed that increasing the relative humidity produced significant changes in the electrical resistance (R) of the PANI, indicating strong humidity-dependent characteristics similar to conventional CPs. In contrast, in the case of in-situ I 2 doping, the R and sensitivity of the PANI remained essentially unchanged when increasing the relative humidity, except for a very low sensitivity of 0.5% under 94% relative humidity. In addition, the R for the PANI with in-situ I 2 doping showed no aging effect, while the R for the ex-situ-doped PANI increased dramatically over time. Thus, it is anticipated that the use of in-situ doping during plasma polymerization can be widely used to design stable and high-performance CPs with humidity-independent characteristics for a variety of applications.

Atmospheric Pressure Plasma Polymerization Synthesis and Characterization of Polyaniline Films Doped with and without Iodine

“…The corresponding resistance was saturated at about 1.0 × 10 3 Ω after 20 min. In most polymer materials, the presence of water in or on the polymer structure changes the resistance and conductivity [ 15 , 16 , 17 , 18 ]. In polymer display applications, however, the I 2 -doped PANI film would be encapsulated by sealing materials to prevent access by moisture and oxygen, thereby protecting the resistance and conductivity [ 38 , 39 , 40 ].…”

“…Use of such system, however, is costly and requires routine maintenance, thereby limiting its application to batch processes. Therefore, an attractive alternative is the use of atmospheric pressure plasma (APP) polymerization for the synthesis of novel thin film materials [ 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 ]. With various advantages, including a low-temperature dry process and low-cost routine maintenance, APP polymerization is a promising growth system for the deposition of novel plasma polymer thin films with functional features that are well-suited for a wide range of applications and substrates.…”

“…The current authors recently reported on an advanced APP jets (APPJs) method for synthesizing new polymers [ 13 , 14 , 15 , 16 ] using intense plasma with a high plasma density in monomer fragmentation (or nucleation or active) and recombination (or passive) regions. The intense and broad plasma is produced using a guide tube and substrate on a polytetrafluoroethylene (PTFE) bluff body installed at the end of the jet, which minimizes any quenching from ambient air and increases the charged particles and density of the plasma in the fragmentation and recombination regions.…”

“…The intense and broad plasma is produced using a guide tube and substrate on a polytetrafluoroethylene (PTFE) bluff body installed at the end of the jet, which minimizes any quenching from ambient air and increases the charged particles and density of the plasma in the fragmentation and recombination regions. In a dry and low temperature environment the proposed APP method can achieve a uniform and stable glow-like plasma discharge with a large area deposition and produce high-quality polymer nanoparticles and nanofibers with an easily controllable morphology, deposition rate, and deposition size, making them well-suited for a wide range of substrates [ 13 , 14 , 15 , 16 ]. Furthermore, the proposed APP polymerization technique does not require a vacuum atmosphere or special equipment.…”

Effects of a Dielectric Barrier Discharge (DBD) on Characteristics of Polyaniline Nanoparticles Synthesized by a Solution Plasma Process with an Ar Gas Bubble Channel

“…Recently, various applications using organic nanoparticles have been intensively studied [ 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 ]. In particular, polyaniline (PANI) has attracted a significant attention because it is applicable to various promising electronic devices such as supercapacitors, sensors, corrosion protective layers, and flexible displays due to such good features as good environmental and high chemical stability, thermal stability, low cost, and easy synthesis [ 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 ]. In general, since a strong DC spark discharge is formed in the conventional SPP, it is difficult to synthesize organic nanoparticles requiring low temperature discharge.…”