Dynamic Assemblies of Molecular Motor Amphiphiles Control Macroscopic Foam Properties

Chen, S., Leung, F. K. C., Stuart, M. C. A., Wang, C. & Feringa, B. L., 3-Jun-2020, In : Journal of the American Chemical Society. 142, 22, p. 10163-10172 10 p., jacs.0c03153.

Research output: Contribution to journalArticleAcademicpeer-review

Stimuli-responsive supramolecular assemblies controlling macroscopic transformations with high structural fluidity, i.e., foam properties, have attractive prospects for applications in soft materials ranging from biomedical systems to industrial processes, e.g., textile coloring. However, identifying the key processes for the amplification of molecular motion to a macroscopic level response is of fundamental importance for exerting the full potential of macroscopic structural transformations by external stimuli. Herein, we demonstrate the control of dynamic supramolecular assemblies in aqueous media and as a consequence their macroscopic foam properties, e.g., foamability and foam stability, by large geometrical transformations of dual light/heat stimuli-responsive molecular motor amphiphiles. Detailed insight into the reversible photoisomerization and thermal helix inversion at the molecular level, supramolecular assembly transformations at the microscopic level, and the stimuli-responsive foam properties at the macroscopic level, as determined by UV-vis absorption and NMR spectroscopies, electron microscopy, and foamability and in situ surface tension measurements, is presented. By selective use of external stimuli, e.g., light or heat, multiple states and properties of macroscopic foams can be controlled with very dilute aqueous solutions of the motor amphiphiles (0.2 weight%), demonstrating the potential of multiple stimuli-responsive supramolecular systems based on an identical molecular amphiphile and providing opportunities for future soft materials.

Original languageEnglish
Article numberjacs.0c03153
Pages (from-to)10163-10172
Number of pages10
JournalJournal of the American Chemical Society
Issue number22
Early online date2020
Publication statusPublished - 3-Jun-2020

ID: 124809305