Liquid-liquid phase-separated commensal membrane gates mass transport in inorganic nanocells

Liquid-liquid phase separation (LLPS), often forming membraneless compartments, is prevalent in proteins and polymers, allowing the functionalities for biological activities and soft material engineering. Yet, direct visualization and manipulation of the full membrane-bound LLPS evolutions with high spatiotemporal resolution remains challenging and undefined. Inspired by dynamic modulation from biological membranes, we in-situ design inorganic nanocells from exciting nanoscale cinnabar with simultaneously forming flexible liquid-like membranes and dense Hg nanodroplets by the electron-responsive LLPS strategy. A full LLPS picture from birth to disappearance, including membrane-associated gating of mass transport either in single nanocell or across multiple nanocells is vividly revealed. Periodic reversible cross-feeding occurs among nanodroplets confined in the single nanocell, in contrast to the conventional Ostwald ripening or coalescence behavior. However, once the ionic balance of the membranes is disturbed by nanobubbles or electrolytes, the nanodroplets collapse. The released less dense species proceed cell-to-cell transport over long distances through nanochannels and are irreversibly crystallized into Hg(I/II) compounds. Ab initio molecular dynamics simulations suggest that the nanodroplet-membrane interface undergoes dynamic charge fluctuations, recognizing the unique membrane-bound LLPS in inorganic systems. The flexible membrane is stabilized through the balance between Hg atoms and ions, which can be destroyed by nanobubbles.