Integrating Organic Quantum Dots into Covalent Organic Frameworks to make Lightweight, Flexible, Conducting Polymers
Abstract
In this program, we will develop Covalent Organic Framework-Quantum Dot (COF-QD) composites to generate flexible, lightweight conducting polymers. These could find use in energy storage, wearable electronics, sensors, etc. QD refers to organic quantum dots (Figure 1). Conducting Organic Polymers is extensively used in flexible electronics. Making them more chemically and structurally tunable without compromising their light-weightiness and flexibility is profitable. COFs are crystalline polymers made with light elements (C, H, N, O, S) with high synthetic tunability. COF s lightweight character and large surface area from their ordered micro-mesopores make them nano compartment for various guest species such as gas molecules, nanoparticles, metal ions, clusters, and organic molecules. A desirable but missing property in a typical COF is its electronic conductivity. Though many COFs have a Graphite-resembling pi-stacked layered structure, every layer in them has pores that reduce the extent of conjugation/unit-cell. In contrast, Graphene s layers are built from fused hexagonal rings on a plane, leading to high conjugation and pi-stacking, which is why their high electronic conductivity. Even COFs formed by combining conjugated monomeric building units show conductivity much lower than expected from its modeled structure. This is due to defects in intra-layer molecular orientation and inter-layer pi-stacking. Organic QDs can be seen as Graphene with limited lateral size. Synthetic QDs are highly conjugated with by-design atomic-composition. The idea here is to lodge these discrete organic QDs as conjugation patches between the COF interlayers and lubricate the adjacent COF layers to slip and stick together at short Vander Waal separations minimizing defects. This would significantly enhance the pi-stacking driven through-plane conductivity. Simultaneously, the QD patches trapped in the pores can be covalently linked with the COF to improve in-plane conductivity- conjugation bridge. This approach is versatile in enhancing COF s electronic, electric and electrochemical properties of COFs.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Nov 16, 2022
- Source ID
- FA23862114022
Entities
People
- Vaidhyanathan Ramanathan
Organizations
- Air Force Office of Scientific Research
- Indian Institutes of Science Education and Research
- United States Air Force