Biomimetic Adhesives Delivered Underwater, with Charges, and from Renewable Resources
Abstract
There is a need for adhesives for repair at sea, underwater construction, and special operations. Nearly all commercial glues, however, cannot form strong bonds in the presence of water. Shellfish, on the other hand, have solved the wet bonding problem. Mussels, barnacles, and oysters fix themselves to wet surfaces with adhesives that are produced by depositing soluble protein mixtures, which are then cross-linked to cure the materials. Since adhesive proteins from shellfish cannot be extracted or expressed at any practical scale, though, attention has turned to generating synthetic mimics of shellfish bioadhesives. With prior ONR support (awards N000140611164, N000141010105, N000141310327) this Principal Investigator~s laboratory has been exploring the chemistry of mussel adhesive proteins for the design of biomimetic adhesives. Mussel adhesive proteins contain the unusual catechol-containing amino acid 3,4-dihydroxyphenylalanine (DOPA), which is responsible for cross-linking proteins to yield the glue with which mussels adhere to wet surfaces. This Principal Investigator~s strategy has been to represent the mussel adhesive with any simple polymer from which catechol groups are appended. He has demonstrated that this materials design process works very well for several different host polymer backbones. The syntheses are straightforward and work on large enough scales to allow for adhesion studies to be carried out in bulk. Significantly, these biomimetic polymers exhibited high strength adhesion. ~Catechol-polystyrene,~ poly[3,4-dihyroxystyrene)-co-styrene], the polymer on which his laboratory has focused the most, was shown to outperform most commercial products against which they benchmarked for underwater adhesion. In the proposed research, the Principal Investigator aims to engineer a practical delivery system for his biomimetic adhesives that can be used by Navy divers in turbulent environments. Additionally, charged groups will be added to the adhesive polymers to enhance bonding in salty water. Evidence has been mounting that charged groups incorporated within polymers influence bonding in salty environments. Finally, mussel chemistry will be combined with a bio-sourced and degradable polymer system to create environmentally benign adhesives with tunable debonding kinetics.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Sep 23, 2016
- Source ID
- N000141612709
Entities
People
- Jonathan Wilker
Organizations
- Office of Naval Research
- United States Navy
- University of Virginia