3P-572 : Polyelectrolyte-grafted Ti 3 C 2 -MXenes stable in extreme salinity aquatic conditions for remediation of contaminated subsurface environments

MXenes are recently gaining significant attention for numerous environmental applications owing to their superior hydrophilicity and unique surface functionalities. However, the use of MXenes for in-situ remediation of contaminated subsurface aquatic environments has not been considered yet. For effective in-situ remediation, it is of primary importance to maintain colloidal stability in harsh subsurface environments. Herein, Ti3C2-MXenes covalently grafted with polyelectrolytes (PEs), MXene-g-PEs, are developed by employing either anionic or zwitterionic PEs. Both MXene-g-PEs have sufficient colloidal stability against the immediate and irreversible aggregation observed for the pristine MXenes in API brines. The MXenes-g-(zwitterionic) PEs show long-term colloidal stability over 6 months in API brine with extreme salinity and little adsorption against α-alumina surfaces. The results suggest a high potential usefulness of the MXene-g-PEs in various subsurface applications.