Non-equilibrium self-assembled nanostructures hold promise for stimulated transitions at otherwise constant conditions. The reliable formation of these structures can be a challenge, especially when considering the delicate balance between kinetic trapping of micelles for long term stability and otherwise implementing the possibility to induce morphological transitions toward the equilibrium structure by applying minute deflections from metastability.
We have introduced a temperature-responsive polymer-based system, allowing considerable changes of the material properties upon triggering the non-equilibrium micelles by various stimuli.[1] Low viscosity dispersions of spherical micelles can be transformed on their way toward equilibrium to gels made of worm-like micelles. This transformation takes place at constant conditions upon application of a temporary trigger. The system remembers the sample`s history, like a past cold wave. Further, the non-equilibrium nature of interpolyelectrolyte complex micelles can be recycled after approaching equilibrium.[2] The interplay between addition/removal of salt as plasticizer and a temperature-responsive polymer gives a handle to modulate the hydrophilic/hydrophobic balance while freezing/melting the micelles. Hence, micellar morphologies obtained at certain conditions can be conserved for other conditions, where the morphology of these micelles is off-equilibrium. Further, we present a micellar system, which memorizes any heat above a certain threshold temperature, as it turns irreversibly turbid upon suffering high temperatures.[3] In addition, we are also interested in transitions of polymeric systems at interfaces. The reorganization of block copolymer micelles at oil-water interfaces was traced by help of interfacial shear rheology and the viscoelastic properties of the resulting monolayer can be adjusted by various means.[4]
[1] F. A. Plamper et al. Adv. Mater. 2017, 29, 1703495.
[2] F. A. Plamper et al. ACS Macro Lett. 2018, 7, 341.
[3] F. A. Plamper et al. ACS Appl. Mater. Interfaces 2023, 15, 57950.
[4] F. A. Plamper et al. Small 2022, 18, e2106956.
