Fuel-Driven π-Conjugated Superstructures to Form Transient Conductive Hydrogels.

Area of Science:

• Materials Science
• Supramolecular Chemistry
• Chemical Engineering

Background:

• Dissipative materials like hydrogels typically show transient structural changes.
• Developing out-of-equilibrium materials with electronically tunable functions via chemical reactions is a significant challenge.
• Biomimetic materials require advanced out-of-equilibrium systems.

Purpose of the Study:

• To engineer far-from-equilibrium conductive hydrogels with electronically tunable properties.
• To utilize reactive fiber structures as resting states for fuel-driven material activation.
• To explore the potential of these materials in advanced applications like biorobotics and chemical computing.

Main Methods:

• Fabrication of fiber structures from reactive naphthalene diimide (NDI) building blocks.
• Employing chemical fuels to initiate a dual-component activation and deactivation pathway.
• Kinetic analysis to understand reaction pathways.
• Cryo-electron microscopy (cryo-EM) to investigate solid-state morphologies.
• Electrical conductivity measurements to quantify functional changes.

Main Results:

• NDI-derived fibers formed far-from-equilibrium conductive hydrogels upon fueling, unlike molecularly dissolved states.
• A distinct dual-component activation/deactivation pathway was observed in the fiber system.
• Cryo-EM revealed morphological transitions from fibers to fibrils and layered superstructures.
• Transient redox-active hydrogels showed a threefold increase in conductivity post-fuel consumption, reverting over hours.

Conclusions:

• Reactive fiber structures serve as effective resting states for creating out-of-equilibrium conductive hydrogels.
• The fuel-driven process enables dynamic control over electronic properties.
• These materials offer a promising platform for programmable biorobotics and chemical computing.