Design and demulsification mechanism of Chlamydomonas reinhardtii-inspired demulsifier based on non-covalent interaction reconstruction

A Chlamydomonas reinhardtii -inspired demulsifier is synthesized for W/O emulsion separation. • MP 12 drives efficient interfacial non-covalent interaction reconstruction. • MP 12 achieves 100% demulsification efficiency at 50 °C across a wide pH range of 4–10. • MP 12 significantly reduces interfacial tension and displaces asphaltenes. • Hydrogen bonds and electrostatic interactions promote the interfacial film rupture. Non-covalent reconstruction is recognized as a critical factor in the destabilization of water-in-oil (W/O) emulsions. However, simultaneously developing highly efficient chemical demulsifiers and capturing the precise molecular mechanisms by which these non-covalent forces cooperatively reconstruct the oil-water interface (OWI) remain significant challenges. To address this, a Chlamydomonas reinhardtii -inspired demulsifier was synthesized via a two-step strategy. Its molecular structure integrates flexible polyether backbones and hydrophobic dodecyl chains, thereby enabling effective modulation of non-covalent interactions and promoting efficient demulsification of W/O emulsions. Systematic demulsification performance evaluations reveal that MP 12 exhibits exceptional demulsification efficiency (DE); at a relatively low temperature of 50 °C, it achieves a DE of 100% across a broad pH range of 4–10, significantly outperforming commercial demulsifiers. Comprehensive interfacial characterizations, including surface tension (SFT), dynamic interfacial tension (IFT), three-phase contact angle (TCA) and coalescence time (CD) measurements, demonstrate that MP 12 effectively penetrates and displaces the rigid asphaltene film at the OWI. Furthermore, quantum chemical calculations and molecular dynamics (MD) simulations confirm that this displacement process is driven by potent hydrogen bond (HB) interactions and high interaction energies between the polyether/hydroxyl groups of MP 12 and water molecules. These atomistic insights successfully elucidate how the demulsifier cooperatively compromises the mechanical integrity of the asphaltene network, providing a solid thermodynamic explanation for the accelerated droplet coalescence observed in experiments. By bridging macroscopic performance with microscopic simulation insights, this work provides a theoretical and practical strategy for the design of high-performance synthetic demulsifiers, offering valuable implications for W/O emulsion treatment. Download: Download high-res image (347KB) Download: Download full-size image