Abstract
Poly(ethylene oxide) (PEO) adsorption behavior on kaolinite surfaces in an aqueous solution was investigated through experiments, the density functional theory (DFT), and molecular dynamics (MD) simulations. The experimental results showed that as the PEO concentration increased, the adsorption capacity first increased then slightly decreased and the turbidity change was opposite. The adsorption isotherm on the kaolinite surface was more suitable for the Langmuir model and valid for single-layer adsorption. The results of simulations showed that the PEO chains extended along the two basal surfaces of kaolinite or were partly adsorbed, forming loops and tails that caused most of the particles to flocculate, contributing to the turbidity lowering. When the number of PEO chains was excessive, their self- and inter-aggregation occured with some PEO far from the surface, and the turbidity increased. On the kaolinite (001) surface, the hydrogen bonds between the PEO ether O and the hydroxyl groups constituted the main interaction mechanism. However, the hydrophobic force of the (CH2–CH2)–moiety of PEO might have dominated its adsorption on the (001 ̅) surface. The hydrogen bonds were stronger than the hydrophobic interactions.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.