Investigating the Adsorption Behavior of Polyaniline and Its Clay Nanocomposite towards Ammonia Gas

Air pollution and control of gaseous air pollutants are global concerns. Exposure to these gaseous contaminants causes several health risks, especially exposure to irritant gases such as ammonia (NH₃). Furthermore, the application of smart polymeric nanocomposites in environmental applications has gained significant interest in recent years. In this study, aniline was polymerized without and with clay using a carbon dioxide (CO₂)-assisted polymerization technique, yielding PANI and PANC samples, respectively. The samples were characterized using different methods, such as Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscope (SEM), and Brunner Emmett Teller (BET). The synthesized nanomaterials were utilized as gas adsorbents using a fixed bed reactor to investigate their adsorption behavior towards NH₃. Three inlet NH₃ concentrations were tested (35-150 ppm). The results revealed that the adsorption capacities of PANC nanocomposites were higher than nanostructured PANI for the studied concentrations. The adsorption capacities were 61.34 mgNH₃/gm for PANC and 73.63 mgNH₃/gm for PANI at the same inlet concentration (35 ppm). The highest NH₃ adsorption capacity recorded was 582.4 mg NH₃/gm, for PANC. This study showed the impressive adsorption behavior of the prepared PANI and PANC nanomaterials towards NH₃ gas. Consequently, nanostructured PANI and PANC can be promising adsorbents that can be utilized to control different gaseous air pollutants.