Το work with title Effect of layer charge and charge distribution on the formation of chitosan - smectite bionanocomposites by Koutsopoulou Eleni, Koutselas, Ioannis, Christidis Georgios, Papagiannopoulos Aristeidis, Marantos Ioannis is licensed under Creative Commons Attribution 4.0 International
Bibliographic Citation
E. Koutsopoulou, I. Koutselas, G. E. Christidis, A. Papagiannopoulos, and I. Marantos, “Effect of layer charge and charge distribution on the formation of chitosan - smectite bionanocomposites,” Appl. Clay Sci., vol. 190, Jun. 2020. doi: 10.1016/j.clay.2020.105583
https://doi.org/10.1016/j.clay.2020.105583
Chitosan-clay bionanocomposites were prepared from chitosan biopolymer solutions and four different smectites (SAz-1 and SWy-2 montmorillonites, SBId-1 beidellite and NAu-1 nontronite), and the effect of layer charge and charge distribution on the formation of bionanocomposites was examined. The intercalation of the chitosan in the homoionic Na+-smectite samples showed that all samples produced chitosan-smectite nanocomposites even at the lowest chitosan-clay ratios. The adsorption isotherms of chitosan by the smectites were classified as L- type isotherms. The equilibrium data were fitted to Langmuir and Freundlich isotherms and the equilibrium adsorption was best described by the Langmuir isotherm model for SWy-2 and SBId-1 while the Freundlich model achieved a better description for SAz-1 and NAu-1 for the higher chitosan concentrations. The adsorption of chitosan exceeded the CEC in the montmorillonites (SWy-2 and SAz-1) whereas in SBId-1 and NAu-1 with tetrahedral charge it either reached or it was lower than the CEC showing that layer charge and charge localization may hinder chitosan adsorption.