Actuation of self-assembled two-component rodlike nanostructures

A model for predicting the effects of stimuli-induced contraction of the polypyrrole ends of two-segment gold-polypyrrole nanorods on their assembly into curved superstructures is presented. The model and experimental data presented here show that small changes (ca. 3%) in the diameter of the polypyrrole segment of each rod will induce dramatic changes (up to 20%) in the radii of the resulting superstructures, providing a convenient means for actuating their opening and closing. We show experimentally that this actuation can be affected via humidity, temperature, and light.