Surfaces with controllable micro structures are significant in fundamental development of superhydrophobicity. However,preparation of superhydrophobic surfaces with array structures on metal substrates is not effectiv...Surfaces with controllable micro structures are significant in fundamental development of superhydrophobicity. However,preparation of superhydrophobic surfaces with array structures on metal substrates is not effective using existing methods. A new method was presented to fabricate super-hydrophobic post arrays on aluminum(Al) substrates using mask electrochemical machining and fluoridation. Electrochemical etching was first applied on Al plates with pre-prepared photoresist arrays to make the post array structures. Surface modification was subsequently applied to reduce the surface energy, followed by interaction with water to realize superhydrophobicity. Simulation and experimental verification were conducted to investigate how machining parameters affect the array structures. Analysis of the water contact angle was implemented to explore the relationship between wettability and micro structures.The results indicate that superhydrophobic surfaces with controllable post structures can be fabricated through this proposed method, producing surfaces with high water static contact angles.展开更多
The porous anodic aluminum oxide (AAO) film on a pure aluminum substrate was pre pared by a two-step anodization in a 0.3M oxalic acid solution and pore-enlargem ent treatment in the phosphoric acid aqueous solution a...The porous anodic aluminum oxide (AAO) film on a pure aluminum substrate was pre pared by a two-step anodization in a 0.3M oxalic acid solution and pore-enlargem ent treatment in the phosphoric acid aqueous solution at 50℃. The diameter of h ighly ordered pore on the AAO film was about 90nm, and the thickness of the AAO film was 3μm. The mineral oil was infiltrated in the ordered nanometer sized po res of AAO film on an aluminum substrate due to the capillarity effect. The fric tion coefficient was measured using a ball-on-disk tribotester. The tests were c onducted at loads range from 490 to 2450mN and at sliding velocities between 0.1 and 0.5m·s-1. Oil infiltration in porous AAO film modified friction and consid erably improved the wear resistance. As compared to the porous AAO film, the oil -infiltrated specimen had low friction coefficient. With increasing the applied load and sliding velocity, the friction coefficient of the oil-infiltrated film decreased. It indicates that the oil-infiltrated AAO film produced a new way to modify the friction and wear of aluminum alloy.展开更多
Optical emissions from the major and trace elements embodied in a transparent gel prepared from cooking oil were detected after the gel was spread in a thin film on a metallic substrate. Such emissions are due to the ...Optical emissions from the major and trace elements embodied in a transparent gel prepared from cooking oil were detected after the gel was spread in a thin film on a metallic substrate. Such emissions are due to the indirect breakdown of the coating layer. The generated plasma, a mixture of substances from the substrate, the layer, and the ambient gas, was characterized using emission spectroscopy. The characteristics of the plasma formed on the metal with and without the coating layer were investigated. The results showed that A1 emission induced from the aluminum substrates coated with oil films extends away from the target surface to ablate the oil film. This finally formed a bifurcating circulation of aluminum vapor against a spherical confinement wall in the front of the plume, which differed from the evolution of the plasma induced from the uncoated aluminum target. The strongest emissions of elements from the oil films can be observed at 2 mm above the target after a detection delay of 1.0μs. A high temperature zone has been observed in the plasma after the delay of 1.0 μs for the plasma induced from the coated metal. This higher temperature determined in the plasma allows the consideration of the sensitive detection of trace elements in liquids, gels, biological samples, or thin films.展开更多
A liquid metal enabled corrosion sculpture technique for quickly fabricating complex pattems on aluminum substrate is proposed and experimentally demonstrated. According to the conceptual investigation, it is clarifie...A liquid metal enabled corrosion sculpture technique for quickly fabricating complex pattems on aluminum substrate is proposed and experimentally demonstrated. According to the conceptual investigation, it is clarified that the width and the depth of a printed track are dominated by sculpture time and working temperature. The printed size can reach small values of 38 μm through controlling the sculpture time for 60 s. As the sculpture time was increased from 5 to 25 rain at 20℃, the depth of the fabricated pattern was improved from 13.3 to 25.6 μm. The sculptured depth of the pattern would increase from 13.3 to 106.9 μm when the sculpture time was fixed at 5 min and the temperature was raised from 20 to 60℃. To investigate the sculpture behavior in detail, the phases and microstructure of sculpture surface were quantitatively measured via a group of microscope imaging system with fundamental mechanisms interpreted. The present liquid metal sculpture method on aluminum substrate adds a new valuable soft tool for current metal engraving technology family.展开更多
基金Supported by National Natural Science Foundation of China(Grant No.51605078)Science Fund for Creative Research Groups of NSFC(51621064)National Basic Research Program of China(973 Program,Grant No.2015CB057304)
文摘Surfaces with controllable micro structures are significant in fundamental development of superhydrophobicity. However,preparation of superhydrophobic surfaces with array structures on metal substrates is not effective using existing methods. A new method was presented to fabricate super-hydrophobic post arrays on aluminum(Al) substrates using mask electrochemical machining and fluoridation. Electrochemical etching was first applied on Al plates with pre-prepared photoresist arrays to make the post array structures. Surface modification was subsequently applied to reduce the surface energy, followed by interaction with water to realize superhydrophobicity. Simulation and experimental verification were conducted to investigate how machining parameters affect the array structures. Analysis of the water contact angle was implemented to explore the relationship between wettability and micro structures.The results indicate that superhydrophobic surfaces with controllable post structures can be fabricated through this proposed method, producing surfaces with high water static contact angles.
基金This work was supported by the National Natural Science Foundation of China(No.50271067)Zhejiang Provincial Natural Science Foundation of China(No.ZC0203).
文摘The porous anodic aluminum oxide (AAO) film on a pure aluminum substrate was pre pared by a two-step anodization in a 0.3M oxalic acid solution and pore-enlargem ent treatment in the phosphoric acid aqueous solution at 50℃. The diameter of h ighly ordered pore on the AAO film was about 90nm, and the thickness of the AAO film was 3μm. The mineral oil was infiltrated in the ordered nanometer sized po res of AAO film on an aluminum substrate due to the capillarity effect. The fric tion coefficient was measured using a ball-on-disk tribotester. The tests were c onducted at loads range from 490 to 2450mN and at sliding velocities between 0.1 and 0.5m·s-1. Oil infiltration in porous AAO film modified friction and consid erably improved the wear resistance. As compared to the porous AAO film, the oil -infiltrated specimen had low friction coefficient. With increasing the applied load and sliding velocity, the friction coefficient of the oil-infiltrated film decreased. It indicates that the oil-infiltrated AAO film produced a new way to modify the friction and wear of aluminum alloy.
基金Acknowledgements The authors thank the French Rhone-Alps Region, the French Centre National de la Recherche Scientifique (CNRS) and the National Natural Science Foundation of China (NSFC) for their supports to the international collaboration and exchange programs. Two of the authors (J. S. Xiu and X. S. Bai) thank the China Scholarship Council (CSC) for their support.
文摘Optical emissions from the major and trace elements embodied in a transparent gel prepared from cooking oil were detected after the gel was spread in a thin film on a metallic substrate. Such emissions are due to the indirect breakdown of the coating layer. The generated plasma, a mixture of substances from the substrate, the layer, and the ambient gas, was characterized using emission spectroscopy. The characteristics of the plasma formed on the metal with and without the coating layer were investigated. The results showed that A1 emission induced from the aluminum substrates coated with oil films extends away from the target surface to ablate the oil film. This finally formed a bifurcating circulation of aluminum vapor against a spherical confinement wall in the front of the plume, which differed from the evolution of the plasma induced from the uncoated aluminum target. The strongest emissions of elements from the oil films can be observed at 2 mm above the target after a detection delay of 1.0μs. A high temperature zone has been observed in the plasma after the delay of 1.0 μs for the plasma induced from the coated metal. This higher temperature determined in the plasma allows the consideration of the sensitive detection of trace elements in liquids, gels, biological samples, or thin films.
基金supported by Beijing Municipal Science and Technology Project(Grant No.Z151100003715002)China Postdoctoral Science Foundation funded project(Grant No.2016M590137)
文摘A liquid metal enabled corrosion sculpture technique for quickly fabricating complex pattems on aluminum substrate is proposed and experimentally demonstrated. According to the conceptual investigation, it is clarified that the width and the depth of a printed track are dominated by sculpture time and working temperature. The printed size can reach small values of 38 μm through controlling the sculpture time for 60 s. As the sculpture time was increased from 5 to 25 rain at 20℃, the depth of the fabricated pattern was improved from 13.3 to 25.6 μm. The sculptured depth of the pattern would increase from 13.3 to 106.9 μm when the sculpture time was fixed at 5 min and the temperature was raised from 20 to 60℃. To investigate the sculpture behavior in detail, the phases and microstructure of sculpture surface were quantitatively measured via a group of microscope imaging system with fundamental mechanisms interpreted. The present liquid metal sculpture method on aluminum substrate adds a new valuable soft tool for current metal engraving technology family.