Wettability of compound organobentonites with ultra-low swelling modified by a series of bis-quaternary ammonium salts

- Compound organobentonites with ultra-low swelling are successfully prepared.
- The wettability of bentonite is obviously changed after modification.
- Compounding of different bis-quaternary ammonium salts has a synergistic effect.
- Relative wettability index (RWI) was first proposed for wettability evaluation.