Langmuir, Vol.24, No.9, 4738-4742, 2008
Time and distance dependence of reversible polymer bridging followed by single-molecule force spectroscopy
Polymer bridging between surfaces plays an important role in a range of fundamental processes in the material and life sciences. Bridges formed by main-chain reversible polymers differ from their covalent analogs in that they can dynamically adjust their size and shape in response to external stimuli and have the potential to reform following bond scission. In this work, the time and distance dependence of main-chain reversible polymer bridge formation are studied using an atomic force microscope. The bridging process was studied using single-molecule force spectroscopy, and its dependence on the distance between surfaces and equilibration time was probed. The number of bridges formed decreases as the gap width increases, from similar to 2 bridges per 14 s equilibration at separations of 5-15 nm to similar to 0.5 bridges per 14 s equilibration at separations of 35-45 nm. The kinetics of bridge formation appear to be slightly faster at smaller separations.