Enhancement of polyaniline properties by different polymerization temperatures in hydrazine detection

Abstract

In this study, a simple and cost effective chemical sensor for hydrazine detection was developed using polyaniline (PAni). PAni was synthesized via chemical oxidative method at different polymerization temperatures (−10, −5, 0, and 25°C) in the presence of sodium dioctyl sulfosuccinate (AOT) as dopant. The effect of polymerization temperature on the performance of the PAni sensor for hydrazine detection was evaluated. The sensor response was analyzed using UV–Vis spectrometer, where there is notable decrease in polaron peak at ∼780 nm after the PAni was exposed to hydrazine. The reduction in the polaron peak is attributed to the decrease in the conductivity of PAni thin films owing to dedoping process by hydrazine. Fourier transform infrared analysis was carried out to study the intensity ratio of quinoid/benzenoid peak to identify the changes in chemical structure of PAni upon exposure to hydrazine. Besides that, all PAni sensors synthesized at different polymerization temperatures showed good reusability up to 10 cycles with respond and recovery time of 0.12 min and 0.08 min, respectively. Data collected in this study indicate that PAni which was synthesized at −5°C could act as sensitive sensor for hydrazine detection with a detection limit of 0.24 ppm. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41746.

Fabrication of Polyaniline Based Chemical Sensor for Ammonia Gas Detection

“…The shoulder peak at ~420 nm attributed to the polaronic character while the peak at ~790 nm contributes to the π-polaron that showed the doped state of quinoid cation. 2,4 Thus, FTIR and UV-Vis spectra confirms the PAni/AOT present in the conducting state which is better known as emeraldine salt. …”

“…2 The presence of emeraldine salt state of PAni/AOT was confirmed by the bands at 1455 cm −1 and 1550 cm −1 that corresponds to the stretching vibration of C=N and C=C at the quinoid site and stretching vibration of C-C benzenoids in the PAni structure. 4 The AOT dopant structure confirmed by C=O and S=O symmetry at 1731 cm −1 and 1178 cm −1 , respectively. 2 The band at 3238 cm −1 and 3158 cm −1 attributed to C-H and N-H at PAni backbone.…”

“…2 The band at 3238 cm −1 and 3158 cm −1 attributed to C-H and N-H at PAni backbone. 4 The O-H arises at 3448 cm −1 due to impurities. Figure 2 shows UV-Vis absorption spectrum of PAni/AOT in the range of 300-900 nm.…”

“…2 However, the PAni has low mechanical strength and processing ability that hinders its performance as a gas sensor. 4 Therefore, in order to improve its processability, doping of PAni with suitable surfactant is commonly used. Up to date, various surfactants have been utilised such as camphorsulfonic acid (CSA), sodium dodecyl sulfate (SDS) and dodecylbenzenesulphonic acid (DBSA).…”

Three-dimensional nanoporous Au films as high-efficiency enzyme-free electrochemical sensors

“…Among these analytical techniques, electrochemical approaches are considered favourable owing to several advantages that include high sensitivity, fast response and low operating cost. Electrodes modified with nanoparticles of metals and oxides, conducting polymer and metal hexacyanoferrates have been explored as electrochemical catalysts for H 2 O 2 [15][16][17][18] or N 2 H 4 detection [19][20][21][22]. Among them, the metal hexacyanoferrates are commonly used as electrocatalysts for such analysis owing to their excellent electrochemical activity.…”