Reversible Heterolytic Mechanophores for Dynamic Bulk Materials

Introduction

Stimuli-responsive polymers adapt their properties in response to external cues. Engineering such “smart” behavior in artificial systems by molecular design is an exciting fundamental challenge that can lead to technological breakthroughs. Most stimuli-responsive polymers rely on heat and light to trigger changes in materials properties in a predictable fashion.

Limitations of Current Approaches

However, limitations intrinsic to these stimuli highlight the necessity of alternative strategies. Naturally evolved systems widely exploit mechanical stimulation to regulate their functions, but recreating such concepts in artificial materials has proven extremely challenging thus far.

Proposed Approach

ReHuse proposes a radically new approach that focuses on the application of mechanical force to induce changes in bulk materials properties isothermally and reversibly. The research project aims at pushing the frontiers of covalent mechanochemistry through the development of reversible heterolytic mechanophores – molecular platforms that dynamically generate and recombine two oppositely charged (macro)molecular fragments upon mechanical stimulation.

Dynamic Chemistries

These new motifs will enable dynamic chemistries involving organic ionic species in solid-state systems in two different types of advanced bulk materials. Combining reversible mechanochemistry and dynamic covalent chemistry will lead to dynamic covalent polymers displaying selective mechanoresponsiveness.

Applications and Impact

This concept will be leveraged to create recyclable materials. The reversible generation of charges from the heterolytic scission will enable the modulation of hydrophilicity/hydrophobicity dynamically. Such principles will be explored to set the groundwork for mechano-responsive atmospheric water harvesters.

Conclusion

This interdisciplinary research project will advance our understanding of mechanochemistry and, more importantly, will usher in new avenues for its productive and repeatable use in adaptive materials.