Feasible Fabrication of Hollow Micro-vesicles by Non-amphiphilic Macromolecules Based on Interfacial Cononsolvency

Herein we present a new perspective showing that water-soluble liquids, when added to water, undergo transient emulsification before complete dissolution. Thus, non-amphiphilic macromolecules can self-assemble at the two-miscible-phase interface when cononsolvent effect appears. A representative case shown here is that when poly(N-isopropylacrylamide) (PNIPAm), prepared by aqueous radical polymerization, in methanol solution is added into water, the polymer chains rapidly self-assemble into hollow micro-vesicles based on the cononsolvency at water/methanol interface. This finding provides a subtle strategy to prepare hollow micro-vesicles by non-amphiphilic polymers without template participating. We proposed a new concept “interfacial cononsolvency” to describe the formation process. Due to the easy modification process, sugar-contained PNIPAm chains are synthesized by copolymerization. As an application example, it is shown that these sugar-contained PNIPAm chains can afford “sweet” micro-vesicles (containing glucose residues). And the “sweet” micro-vesicles can well mimick the protocells which are involved in the recognition of bacteria.