Method for varying the diameter of a nanopore contained in a nanoporous membrane functionalised with a ph-dependent polyelectrolyte

摘要

The variable diameter nanoporous device (14) comprises a functionalized radio-grafted track-etched membrane (FRTEM) containing nanopores (18), which are radiografted by a polyelectrolyte, and two electrodes adapted to provide a variable potential difference in a region in an aqueous or solvent polar solution (15). The pH of the region is intended to vary as a function of the potential difference due to electrolysis. The FRTEM and the two electrodes are arranged in the aqueous solution in such a way that the nanopore is included in the region. The variable diameter nanoporous device (14) comprises a functionalized radio-grafted track-etched membrane (FRTEM) containing nanopores (18), which are radiografted by a polyelectrolyte, and two electrodes adapted to provide a variable potential difference in a region in an aqueous or solvent polar solution (15). The pH of the region is intended to vary as a function of the potential difference due to electrolysis. The FRTEM and the two electrodes are arranged in the aqueous solution in such a way that the nanopore is included in the region. The effective diameter or hydrophilicity of the polyelectrolyte changes as a function of the potential difference. The nanopore consists of tubule through the entire thickness of the functionalized FRTEM. One of the two electrodes is composed of two surface electrodes (21) respectively arranged on each side of the FRTEM perpendicularly with respect to the nanopore, where each surface electrode comprises an aperture so that the nanopore remains open and the other electrode is disposed in the same solution as the FRTEM. The surface electrodes are connected together. Each surface electrode provides an independent potential difference with respect to another electrode, and is a sputtered metallic layer that enters the nanopores on some hundreds of nm. The thickness of the FRTEM is of 9 mu m and the nanopore has a diameter of 20-100 nm. The potential difference between the two electrodes is obtained using a potentiostat, where the voltage of the variable electrode is less than 5 V.