Film Chemistry Control and Growth Kinetics of Pulsed Plasma-Polymerized Aniline

Abstract

The polymerization of aniline under continuous and pulsed RF-plasma conditions is studied using the same plasma reactor. The effects of input power, on and offtimes, frequency and duty cycle variations on the growth kinetics and on the chemical structure of the obtained layers are examined. The chemical structure of the films is characterized using Fourier Transform Infra-Red, X-ray photoelectron and UltraVioletVisible spectroscopies. The thickness of the films is determined by profilometry. The results show a strong dependence of film chemistry and deposition rates on the discharge power and on-time. The film deposited by pulsed plasma grows mainly during the plasmaon period. Furthermore, this work shows that the retention of aromatic rings can be evaluated by Fourier transform infrared analysis whereas oxidation degree of plasma polyaniline can be determined by X-ray photoelectron and UV-Vis spectroscopies.

Extended Conjugation in Polyaniline Like Structure Prepared by Plasma Polymerization Suitable for Optoelectronic Applications

“…The bands at 696 and 752 cm -1 suggest crosslinking in plasma-PANI. The weak intensity band at 835 cm -1 compared to 696 and 752 cm -1 is the sign of branched and crosslinked polymeric structure [17]. Figure 2c shows the plot of ratio of bands area of saturated C-H stretch to unsaturated (aromatic and alkenes) C-H stretch as a function of polymerization time.…”

“…Photoluminescence (PL) study of plasma polyaniline is an effective way to understand the electronic structure, optical and photophysical properties by which the information such as defects, charge carrier trapping, p-electron delocalization along the backbone and crosslinked chain may be obtained. Even though a number of studies of plasma polymerized aniline film formation have been reported [17,18] earlier, there is not much detailed information of plasma polyaniline films which exhibits extended conjugation and broad absorption band in the ultraviolet (UV) and entire visible region. Moreover, the smooth deposition results the formation of interference fringes in the NIR region of transmittance spectra that gives the more insight to the hardly studied non linear optical properties of plasma polyaniline films from the single transmittance spectrum.…”

Polyfluorene Thin Films Synthesized by a Novel Plasma Polymerization Method

“…Introduction p-Conjugated polymers (CPs), such as polyfluorene (PF), polythiophene, polyaniline, and their derivatives have been widely studied due to their potential applications as active layers in organic electronic and chemical sensor devices [1][2][3][4]. Besides their intrinsic conductivity, the advantages of CPs are the diversity of structures and tunability of properties offered through molecular design.…”

A Detailed Description of the Chemistry of Thiol Supporting Plasma Polymer Films

“…As propanethiol does not contain any unsaturation (double, triple bond) therefore preventing its grafting at the interface during t off , it can reasonably be assumed that the growth of the layer occurs mainly during t on . [33] Since in our experiments, P peak and t on are fixed, we can expect similar energetic conditions in terms of ionic bombardment during the synthesis and hence a similar momentum flux. In order to get information on the chemistry of the plasma phase, which represents the second element to evaluate in order to understand the data reported in Figure 2a, mass spectrometry measurements are performed.…”

“…Therefore, in our case, considering our experimental condition (working pressure of 40 mTorr, P peak fixed at 100 W) it could be assumed that the neutrals species contribute mainly to the layer growth as also pointed out in previous studies. [33,36,48] Hence, the mass spectrometry measurements are performed in residual gas analysis (RGA) mode. Figure 3a shows the RGA mass spectrum measured for the propanethiol vapor (Plasma OFF).…”