Cyclic organic carbonate modification of sodium bentonite for enhanced containment of hyper saline leachates

• GC/Na+-bentonite retained more COC than PC/Na+-bentonite at high I salt solutions.
• CO groups of COC interact with the interlayer cations through water at low I.
• GC was more effective in linking directly to interlayer Na+ compared to PC at high I.
• GC OH H-bonded with surface oxygens of Mt.
• GC/Na+-bentonite was found to be a more stable material than PC/Na+-bentonite.