나노허니컴과 극소수성 나노구조물의 설계 및 응용

Abstract

Anodic aluminum oxide (AAO) nanohoneycomb structures have been proposed as a material suitable for use in nanotechnology. Porous type AAO nanohoneycomb has the attractive feature of allowing simple control of pore dimensions, diameter, pore length and density by varying the anodizing conditions. By controlling the pore size of the AAO nanohoneycomb structures, we developed a simple and inexpensive method for fabricating superhydrophobic tangled nanofiber structures with ultralow contact angle hysteresis and no aging degradation using common aluminum foil (99.5%). The nanofiber structures have low contact angle hysteresis as the nanofibers are thicker and denser, so that it is possible to design more robust nonwetting surfaces. Furthermore, the widened nanofiber structures maintain superhydrophobicity even after storage in air or water for three months, confirming that these structures are stable and reliable. Superhydrophobic surfaces have been fabricated for many biological and engineering applications. However, due to the delamination of the nanostructured layer from a handling layer during the fabrication process, we could not have obtained uniform nanostructured surfaces in large area. Here, we first report tens of centimeter-scale superhydrophobic nanostructures with flexibility, cost-effective, no aging degradation and drag reduction by adopting curing process, which have uniform superhydrophobic nanostructured surfaces on the size of 30 ？e 14 cm2. This fabrication method is simple, economical, and reproducible. Moreover, this method can be extended to 3D shape structures for various purposes because of flexibility. We further demonstrated the drag reduction up to 28.5% in the large-area nanofiber structures with low contact angle hysteresis. Such a nanofiber structures could be a potential platform for many applications such as microfluidic devices for biological studies, and industrial self-cleaning products for automobiles, ship and house. AAO nanohoneycomb produces a hole configuration with long-range ordering and high aspect ratio, and it is possible to achieve high pore densities (>1010 cm&#8722

2)

the surface can also easily be modified using a self-assembled monolayer (SAM). Based on self-organized AAO nanohoneycomb structures, we developed a novel nanofilter with antifouling and superior immunoprotection by coating polyethylene oxide (PEO) on the nanohoneycomb structure with 18 nm in diameter. In order to optimize the nanofilter geometry for achieving high permeability of glucose and insulin while blocking IgG, the length of PEO coated on the nanofilter was controlled to be around 1.7nm. Since the pore size of a PEO-coated nanofilter can be slightly smaller than the size of IgG, and the IgG would be prevented from passing through nanofilter while the passage of glucose and insulin would be maximized. The nanofilter can provide a high-throughput and cost-effective fabrication process, as well as a large-area uniform and straight nanopore for the nanofilter with high mechanical stability and tunability of the pore geometry. Thus our nanofilter might produce a promising biofiltration platform of a variety of biomolecules for biomedical treatments as well as novel building block for artificial cell membranes.