Polymer tubes with longitudinal composition gradient by face-to-face wetting

Nanoporous and macroporous templates were simultaneously infiltrated from both of their opposite surfaces using model polymers labeled with fluorescent probes or bearing probe molecules detectable by energy-dispersive X-ray spectroscopy by precursor wetting. Face-to-face wetting with polymeric solutions resulted in partial mixing of both components, leading to tubular nanostructures characterized by a longitudinal composition gradient. Mixing of the components infiltrated from the opposite surfaces could be prevented by face-to-face wetting with polymeric melts, leading to the formation of tubular components predominantly consisting of the pure components that were separated by sharp interfaces.