Preparation And Wettability Analysis Of Micro-Nano-composite-structures With Controlled Morphology

In this paper,high purity aluminum foil as a substrate,and the micro-cavity array structure was prepared by combining the UV lithography and wet etching process.Then,two-step anodic oxidation process and water bath process were used to prepare the micro-cavity array structure,which successfully obtained two kinds of micro-nano composite structure materials.The morphology of two kinds of micro-nano composite structures was analyzed by field emission electron microscopy.Among them,the removing process in the preparation of the composite structure(the oxide layer produced after the first anodic oxidation removal)and the second anodic oxidation working all have a great influence on the order and regularity of the nanopores;After the use of deionized water bath(60?,80? and 100?),the flaky micro-nano composite structure can be directly formed,and the tap water bath does not produce flaky structure when the temperature is 60 ? and 80 ?,the reason is that the reaction process of the tap water bath will become slow due to the presence of chloride ions(Cl-).When the temperature rises to a certain extent,the chloride ions react with other ions to reduce the presence of chloride ions,resulting in leaf-nanostructures.It was found that the water bath time affected the number of spherical nanostructures and the density and the degree of crosslinking of the lamellar nanostructures.The water bath temperature affected the formation of nanostructures(spherical or flaky);For the nano-leaf-like structure of deionized water as solvent,the bath temperature affects the tilt angle,the number and the degree of cross-linking of the leaf-like structure,and the bath time affects the thickness of the leaf-like structure.Finally,the wettability of PAA-/AlOOH-micro-nano-composite-structures were investigated.5?L droplet completely spreads on PAA-micro-nano-composite-structure(5?m×5?mperiodic micro-array)within 20ms,the WCA is 0°,which shows the super-hydrophilicity;And 5?L droplet completely spreads on AlOOH-micro-nano-composite structures within 1.5s,the WCA is 0°,and also shows a super-hydrophilicity.Comparing with pure nano-PAA films and microarray,the PAA-micro-nano-composite-structure can provide uniform surface with significantly better hydrophilicity;And comparing with pure nano-AlOOH structure,the AlOOH-micro-nano-composite-structure can also provide better hydrophilicity.