The collapse of an elastic tube induced by encapsulated liquid droplets

Using molecular dynamic simulations, we studied the equilibrium structure of an elastic nanotube filled with separated liquid droplets. When the filling of liquid droplets exceeded a certain critical ratio, the circular carbon nanotube was observed to be deformed into an elliptical one, associated with the coalescence of liquid droplets. We have proposed a theoretical model to explain such an abrupt structural deformation. Based on the competition between capillary and elastic energy, our theoretical model explained the collapse of the elastic tube very well and gave consistent predictions with the simulation results. The theoretical model was quite general and can be extended to other similar soft matter systems although it was originally deduced from the liquid-filled carbon nanotube systems.