Reconciling bond strength of a slip bond at low loading rates with rebinding

Conventional theory predicts that molecular bond strength becomes trivial at very low loading rates, which, however, failed in some experiments probably due to hidden rebinding. Here we propose average bond strength as an alternative physical quantity to be measured in dynamic force spectroscopy experiments. Our analysis indicates that there exists an asymptotic value of average bond strength at low loading rates, which, nevertheless, increases with the spring constant of the loading system. This finding is subsequently confirmed with the Monte Carlo simulation. The proposed average bond strength can be informative in the understanding of the intriguing behaviors of molecular bonds at low loading rates