ADHESION MECHANISMS

Multivalent interactions play show enhanced strength and better selectivity compared to monovalent interactions, but they are much less understood due to their complexity.

Using AFM-based single molecule force spectroscopy. we detect molecular interactions in the range of a few piconewtons to several nanonewtons and correlate them with the formation and subsequent breaking of one or several bonds and assign these bonds. We use a multifunctional polymer that is covalently attached to an AFM cantilever tip to contact a polymer layer of the multifunctional polymer bound to a solid substrate. Varying the crosslinking state of the polymer layer, we find that bonds of intermediate strength (non-covalent), like coordination bonds, give the highest multivalent bond strength, even outperforming strong (covalent) bonds.

Multivalent interactions can be used to design stable and durable polymer coatings, in particular keeping the number of non-covalent interactions at a high level.

 

Literature: 

M. Lallemang, L. Yu, W. Cai, K. Rischka, A. Hartwig, R. Haag, T. Hugel* & B. N. Balzer*

Multivalent non-covalent interactions lead to strongest polymer adhesion

Nanoscale, 14, 3768 (2022). http://dx.doi.org/10.1039/D1NR08338D