Electrical double layer at the gibbsite/anionic polyacrylamide/supporting electrolyte interface – Adsorption, spectroscopy and electrokinetic studies.

The main aim of the study was to investigate the electrical double layer (EDL) structure formed at the gibbsite/supporting electrolyte/anionic polyacrylamide (PAM) interface. It was carried out based on the results of the following measurements: the FTIR spectroscopy, the adsorption and zeta potential measurements as well as the potentiometric titration. The solid texture properties were also determined using the nitrogen adsorption/desorption isotherm method. The obtained results showed that the anionic polyacrylamide adsorbs on the gibbsite surface in the whole examined pH range. The adsorption amount strongly depends on the pH value, i.e. the higher pH is, the lower adsorption level is observed. The PAM adsorption changes both the surface charge density and the zeta potential of gibbsite. The data presented are greatly helpful in assessing PAM flocculating ability relative to the soil mineral. [ABSTRACT FROM AUTHOR]