Deciphering the adhesive properties of mussel-inspired metal-coordinate physical gels

Poster Session: 

A

Presenter: 

Erica Lai

Authors: 

Erica Lai, Dr. Bavand Keshavarz, and Professor Niels Holten-Andersen

Author Affiliation: 

Department of Materials Science and Engineering, MIT

Abstract: 

In recent years, researchers have incorporated mussel-inspired metal coordination into various types of gels to improve their mechanical properties, particularly toughness and self-healing. However, not much is understood about how known methods for tuning the viscoelastic spectrum of these gels affect their adhesive properties. In this study, both rheological and tack tests are performed on metal-coordinate physical gels comprised of 4-arm polyethylene glycol end-functionalized with histidine (His) and divalent metal ions (M2+). Understanding how the ligands participate in each of the HisnM2+ species within a gel helps us determine the correlation between linear mechanical properties (i.e. plateau modulus, characteristic relaxation time) and resulting non-linear behavior (i.e. peak stress, adhesion energy). With this understanding, incorporating metal coordination into adhesive materials could provide condition-dependent control of adhesive properties.