Stimuli responsive self-assembled structural aggregates of ionic liquid based surfactants as the membrane free microreactors for dyes sequestration and drug encapsulation

Abstract

Judiciously designed surfactant based protocell models such as micelles, vesicles, gels and coacervates with higher thermal stability, low-toxicity and bio-compatibility found applications in various new age technologies. In our attempt to obtain the membrane free microreactors for accumulating dyes and biomolecules within a single system, herein we had designed ionic liquid (ILs) based simple coacervates. These coacervates were formed by merely changing solution pH of ester functionalized imidazolium and morpholinium based surface active ILs with varied alkyl chain length and anions. On reaching the neutral pH, the large isotropic (micellar and vesicular) phase de-mixes into two conjugate phases; the dense coacervate phase in equilibrium with the dilute phase. Stability of these membrane free microreactors were studied in the presence of mono and divalent salt solution, viscous solution, higher temperature and acidic as well as alkaline solutions for their realistic applications. These newly formulated microreactors were investigated for the membrane free transport of neutral, cationic, and anionic dyes under non-equilibrium conditions. The same coacervate droplets further show excellent encapsulation for the anticancer hydrophobic drug, curcumin; opening an all new avenue in drug delivery. Presently investigated environmentally benign simple coacervates could replace their costly and inefficient natural analogous for multi-purpose applications including biomimetic operations.