Impact of Two Water-Miscible Ionic Liquids on the Temperature-Dependent Self-Assembly of the (EO)6-(PO)34-(EO)6 Block Copolymer

There are many studies on the self-assembly of triblock poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) copolymers in aqueous solution. These polymers display a rich phase diagram as a function of block length, concentration, temperature, and additives. Here, we present a small-angle neutron scattering study of the impact of two water-miscible ionic liquids, 1-butyl-3-methylimidazolium chloride ([C(4)C(1)mim] [Cl]) and 1-butyl-3-methylpyrrolidinium chloride ([C(4)C(1)pyrr] [Cl]), on the temperature-dependent self-assembly of (EO)(6)-(PO)(34)-(EO)(6), also known as L62 Pluronic, in aqueous solution. Both ionic liquids depress the temperatures of the various structural transitions that take place, but ([C(4)C(1)pyrr] [Cl]) has a stronger effect. The structures that the triblock copolymer self-assembles into do not dramatically change nor do they significantly change the series of structures that the system transitions through as a function of temperature relative to the various transition temperatures.

Automated summary

This study investigates the impact of two water-miscible ionic liquids on the temperature-dependent self-assembly of triblock copolymers in aqueous solution. The results show that both ionic liquids lower the temperature of structural transitions, with one of the liquids having a stronger effect. Additionally, the self-assembled structures of the copolymer do not change significantly.