Liu, Erming and Sarkar, Binoy and Wang, Liang and Naidu, Ravi (2016) Copper-complexed clay/poly-acrylic acid composites:Extremely efficient adsorbents of ammonia gas. Applied Clay Science, 121-12. pp. 154-161. ISSN 0169-1317
Full text not available from this repository.Abstract
Work reported in this manuscript takes into consideration the possible use of NH3 gas by terrorists and the potential for an effective and rapid removal of such toxic substance from air using a modified clay material. In this study, a series of clay/polymer composites were synthesised for ammonia gas (NH3) adsorption. The adsorbents were prepared by polymerisation of acrylic acid with N,N'-methylenebisacrylamide (MBA) as cross-linker in the presence of a large amount of highly dispersed clay nanoparticles, followed by interaction with copper ions (Cu2+). Two kinds of clays were used. One was an acid-treated bentonite that had a specific surface area (SSA) of 395 m2/g and the other was natural palygorskite with a SSA of 87 m2/g. The materials were characterised by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), nitrogen adsorption-desorption and Fourier transform infrared spectroscopy (FTIR). The materials' ability to remove NH3 was investigated using NH3 breakthrough dynamic test while the strength of NH3 retention was characterised by Thermogravimetric Analysis (TGA) coupled with FTIR. The results indicate that clay/poly-acrylic acid composites are highly efficient adsorbents of NH3 after binding with Cu2+. Trapping NH3 on such adsorbents can lead to colour change and this makes it possible to predict the lifetime of the adsorption bed visually. In addition, the result of NH3 release from the material following adsorption showed that majority of the adsorbed NH3 desorbed at temperature above 180°C. The clay/polymer composites can potentially be used in air filters. They may provide an effective and cheap way for removing NH3 from contaminated air.