Nanostructured Polyaniline Films Functionalized through Auxiliary Nitrogen Addition in Atmospheric Pressure Plasma Polymerization

Abstract

Polyaniline (PANI) was synthesized from liquid aniline, a nitrogen-containing aromatic compound, through the atmospheric pressure (AP) plasma process using a newly designed plasma jet array with wide spacing between plasma jets. To expand the area of the polymerized film, the newly proposed plasma jet array comprises three AP plasma jet devices spaced 7 mm apart in a triangular configuration and an electrodeless quartz tube capable of applying auxiliary gas in the center of the triangular plasma jets. The vaporized aniline monomer was synthesized into a PANI film using the proposed plasma array device. The effects of nitrogen gas addition on the morphological, chemical, and electrical properties of PANI films in AP argon plasma polymerization were examined. The iodine-doped PANI film was isolated from the atmosphere through encapsulation. The constant electrical resistance of the PANI film indicates that the conductive PANI film can achieve the desired resistance by controlling the atmospheric exposure time through encapsulation.

Improvement of Electrical Conductivity of In Situ Iodine-Doped Polypyrrole Film Using Atmospheric Pressure Plasma Reactor with Capillary Electrodes

“…This presence of high-energy electrons in I 2 plasma causes inelastic collisions between these electrons and N 2 species, contributing to the increase in the N 2 peak at 337.1 nm in Figure 4 . This N 2 peak at 337.1 nm corresponds to the emission intensities of the nitrogen band of the second positive system at 337.1 nm [ 41 , 42 , 43 , 44 ]. In addition, as the residence time of inflowing N 2 gas increases in a closed guide tube, N 2 gas actively collides with Ar gas and electrons.…”

“…Moreover, the PPy film growth was performed under ambient air in the APPR, and therefore, air, including N 2 , would be employed in the APPR during the PPy film growth. Some of the N 2 from the air would be transformed into excited N 2 species owing to the plasma energy [ 44 ]. When injecting the I 2 vapor for in situ I 2 doping, the N 2 peaks would be increased by high-energy electrons in I 2 plasma through an inelastic collision between electrons and Ar gas in Figure 4 .…”

“…When injecting the I 2 vapor for in situ I 2 doping, the N 2 peaks would be increased by high-energy electrons in I 2 plasma through an inelastic collision between electrons and Ar gas in Figure 4 . Notably, an increase in the N 2 peak at 337.1 nm can contribute to improving the intensity of all major peaks, including those corresponding to the functional groups of the PPy ring structure [ 44 ]. The formed I 2 peaks resulted from I 2 species, such as molecular and atomic emission of I 2 , which was formed through an ionization reaction by an I 2 plasma from the heated I 2 vapor injection [ 39 ].…”

“…The characteristic peaks in the PPy film spectra were observed at 3329, 2968, 2879, 1680, 1536, 1239, and 1043 cm −1 . The peak at 3329 cm −1 was assigned to N–H stretching [ 44 , 47 ]. The peaks at 2968 and 2879 cm −1 , which were ascribed to aliphatic C–H stretching absorptions, indicated fragmentation of some pyrrole rings in the polymer [ 47 , 48 , 49 ].…”

“…The peaks at 2968 and 2879 cm −1 , which were ascribed to aliphatic C–H stretching absorptions, indicated fragmentation of some pyrrole rings in the polymer [ 47 , 48 , 49 ]. The peaks at 1043, 1239, and 1536 cm −1 were assigned to C–H in-plane band stretching, C–N stretching, C=C, and C–C ring stretching, respectively [ 30 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 ].…”