Large-scale orientated self-assembled halloysite nanotubes membrane with nanofluidic ion transport properties

Abstract

One of the significant challenges in nanoscience and nanotechnology is how to make macroscopic devices by assembling nano-building blocks while maintaining their extraordinary properties. Here we show a large-scale orientated membrane based on halloysite nanotubes which can be self-assembled on glass substrate by using isothermal heating evaporation induced method. The halloysite nanotubes exhibit the maximum alignment degree when the halloysite dispersion was dried at 80 °C with the concentration of 10 mg mL−1 and the pH of 6. The birefringence observed over the membrane indicates the presence of the nematic liquid crystalline phase with aligned nanotubes. The uniform space between the nanotubes in the orientated membranes forms nanochannels which could be used for ion transport. Surface-charge-governed ion transport behavior is observed through these nanochannels at KCl concentrations below 10−4 M. The ease of constructing large-scale and stable nanochannel arrays offer many new exciting opportunities for studies of ion transport as well as new device designs.