The Effect of Sugar Content for the Wettability of Superhydrophobic Aluminum Substrate

A chemical etching technique is used to prepare a superhydrophobic surface with a honeycomb rough structure on the aluminum surface. Use SEM, Optical contact angle meter and Surface tension detector to characterize the etched aluminum substrate. After the 8th etching, the surface of the sample showed the morphology of micro/nano-scale honeycomb pores and protrusions, and the water contact angle (WCA) is 135°. After being modified with octadecanethiol methanol solution, WCA is 153.1°. After modification, the contact angle of the sample surface decreases with the increase of the glucose solution concentration. When the glucose solution concentration reaches 1000 mg/L, the superhydrophobicity is lost.

Improving the Specific Surface Area of Etched Aluminum Foil by Fabricating the Micro/Nano Structure

Aluminum foil with micro/nano structure has been prepared by electrochemical DC etching and a subsequent anodization treatment followed by removal of the alumina film. When the micron-sized tunnels were generated on the etched aluminum foil, the size and distribution of the nano-concave formed on the sidewall of the etched tunnels varied with the anodized time in H2SO4 and C4H6O6 electrolyte. The optimal value of the specific surface area for the aluminum foil with micro/nano structure is approximately four times larger than that of the only etched aluminum foil. It is indicated from the chronoamperometry and BET measurements that the specific capacitance of aluminum foil with micro/nano structure can be significantly improved by suitable anodization in H2SO4 electrolyte, in comparison with a comparatively small increasement in C4H6O6 electrolyte. This can be attributed to the fact that the tardy anodization process will consume a considerable amount of aluminum substrate, resulting in the aggravation of the merged tunnels.

Rapid and tunable growth of well-ordered hexagonal nanoporous anodic aluminum oxide (AAO) structure by two step high temperature anodization

In this study, we have developed a swift and well-ordered growth of the Anodic Aluminum Oxide (AAO) nanoporous structure by two-step high temperature anodization of pure Aluminum substrate. The pre-anodization surface treatment of the aluminum substrate assists in the formation of well-organized nanoporous structures. The two-step anodization process was performed in 0.3 M of oxalic acid at 20 °C for 40 V and 45 V to obtain tunable pore diameters. The high temperature of the electrolyte solution helps in the rapid growth of the AAO nanoporous structure. The top surface image of AAO shows a well-ordered nanoporous structure with an average pore diameter of 70 nm at 40 V and 100 nm at 45 V. The SEM cross sectional view also illustrates the well-ordered nano channel and the elemental mapping elaborates the presence of aluminum and oxygen. The thickness of the AAO nanoporous structure was determined by using SEM for three anodization time spans (20, 24 and 28 hours), in which an increasing trend was observed. The fabricated AAO has a higher thickness and a well-ordered nanoporous structure that shows it can be used as a template for fabricating nanostructured materials.

Degradation of the Layer Applied by Cold Kinetic Deposition

During the described experiment, a sample with a copper coating was formed on an aluminum substrate by cold spray. Subsequently, this sample was split for corrosion tests, where the split samples were exposed to a corrosive environment for different exposure times. The extent of corrosion degradation of the samples was evaluated by acoustic emission and metallographic analysis for corrosion-loaded samples for 100, 200 and 300 hours.

Enhanced output of ZnO nanosheet-based piezoelectric nanogenerator with a novel device structure

We report the double-fold enhancement of piezoelectric nanogenerator output voltage with a simple design strategy. The piezoelectric nanogenerator is fabricated with ZnO nanosheets coated on both sides of the aluminum substrate in this new design strategy with necessary electrodes. The cost-effective hydrothermal method is employed to synthesize two-dimensional (2D) ZnO nanosheets on both sides of the aluminum substrate at a low growth temperature of 80˚C for 4 hours. The ZnO nanosheets were characterized for their morphology, crystallinity, and photoluminescence property. The nanogenerator is fabricated with a double-side coated aluminum substrate and compared its performance with a single-side coated aluminum substrate. The nanogenerators fabricated only with one side coating produced an output voltage of ~ 170 mV. In contrast, the nanogenerators fabricated with a double side coating produced an output voltage of ~ 285 mV. The nanogenerator with double-side coating produced ~1.7 times larger voltage output compared to the voltage output from one side coated nanogenerators fabricated with each side of the substrate. The enhancement in the output