Impact of Two Water-Miscible Ionic Liquids on the Temperature-Dependent Self-Assembly of the (EO) 6 -(PO) 34 -(EO) 6 Block Copolymer.
William T HellerChangwoo DoPublished in: ACS omega (2022)
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.