Programmable Spatial Demixing in Prebiotic Coacervates

Area of Science:

• * Origin of life studies
• * Physical chemistry
• * Astrobiology

Background:

• * Protocell stratification is vital for molecular exchange and chemical complexity.
• * Achieving stratification under prebiotic conditions is challenging.
• * Physical encounters between protocells are essential for evolution.

Purpose of the Study:

• * To investigate how minimal structural variations in amphiphiles affect protocoacervate buoyancy and stratification.
• * To explore the role of environmental factors in modulating protocoacervate positioning.
• * To elucidate the physicochemical mechanisms governing protocoacervate spatial organization and interaction.

Main Methods:

• * Systematic tuning of amphiphile and small molecule parameters (isomers, alkyl-chain length, counterion).
• * Observation of coacervate buoyancy and vertical migration in aqueous columns.
• * Structural analysis of coacervate architecture and hydration properties.
• * Investigation of temperature and concentration effects on droplet positioning.

Main Results:

• * Minimal structural variations (isomers, chain length, counterion) dictate coacervate buoyancy and stratification.
• * Coacervates can be tuned to reside in upper or lower aqueous phases.
• * Hydration layer thickness and hydrophobic-to-hydrated ratio determine vertical positioning.
• * Temperature changes dynamically modulate droplet position, inducing collisions and fusion.

Conclusions:

• * Subtle molecular variations can encode spatial organization and interaction frequency in protocell-like systems.
• * Physicochemical mechanisms govern protocell positioning and interaction in stratified environments.
• * This study provides insights into how early life could achieve spatial organization and molecular exchange.