Study of thermal decomposition of hay-based activated biocarbons modified with nanolayers of ionic polyacrylamide

Abstract

AbstractThe thermal behaviour of hay-based activated carbons modified with adsorption nanolayers of ionic polymers were investigated. The anionic and cationic forms of polyacrylamides (PAM) with different contents of ionizable groups were applied. Using spectrophotometry, potentiometric titration, microelectrophoresis, DCS (Differential Centrifugal Sedimentation) and thermal analysis methods, the adsorption and electrokinetic, properties, as well as thermal stability of studied activated biocarbons—PAM systems were established. It was shown that PAM adsorbed amounts on the activated biocarbon surfaces were considerably higher for cationic polyacrylamides than for anionic ones. The conducted TG-DSC-FTIR/MS analysis in helium showed a significant influence of the synthesis conditions on the content of oxygen surface groups of activated biocarbons obtained in conventional or microwave muffle furnace. The measurements carried out in the oxidizing atmosphere for the polymer-modified samples showed similarity to the original materials and were characterized by three main stages of decomposition: dehydration, decomposition of surface functional groups and, at high temperatures—combustion process. The main decomposition products were CO2 and H2O.