Reversible Control of Primary and Secondary Self-Assembly of Poly(4-allyloxystyrene)‎-Block-Polystyrene

Abstract EN

The reversible control of primary and secondary self-assemblies was attained using a poly(4-allyloxystyrene)-block-polystyrene diblock copolymer (PASt-b-PSt) through variations in temperature.

The copolymer showed no self-assembly in cyclohexane over 35∘C and existed as a unimer with a 37.1 nm hydrodynamic diameter.

When the temperature was lowered to 30∘C, the copolymer formed micelles with 269.9 nm by the primary self-assembly.

As the result of further lowering the temperature to 20∘C, the secondary self-assembly of the micelles occurred to produce ca.

2975.9 nm aggregates.

The aggregates were dissociated into unimers by increasing the temperature up to 40∘C.

The light scattering studies demonstrated that the thermoresponsivity of the copolymer showed good hysteresis throughout the variation in the temperature in the range between 20 and 40∘C, based on the Marquadt analysis of the hydrodynamic diameter distribution.

It was found that the primary and secondary self-assemblies of the copolymer were perfectly controlled by the temperature.