Many biological surface are hydrophobic because of their complicated composition and surface microstructure. Eleven species (four families) of butterflies were selected to study their micro-, nano-structure and super...Many biological surface are hydrophobic because of their complicated composition and surface microstructure. Eleven species (four families) of butterflies were selected to study their micro-, nano-structure and super-hydrophobic characteristic by means of Confocal Light Microscopy, Scanning Electron Microscopy and Contact Angle Measurement. The contact an- gles of water droplets on the butterfly wing surface were consistently measured to be about 150 ? and 100 ? with and without the squamas, respectively. The dust on the surface can be easily cleaned by moving spherical droplets when the inclining angle is larger than 3 ?. It can be concluded that the butterfly wing surface possess a super-hydrophobic, water-repellent, self-cleaning, or “Lotus-effect”characteristic. The contact angle measurement of water droplets on the wing surface with and without the squamas showed that the water-repellent characteristic is a consequence of the microstructure of the squamas. Each water droplet (diameter 2 mm) can cover about 700 squamas with a size of 40 m×80 m of each squama. The regular riblets with a width of 1000 nm to 1500 nm are clearly observed on each single squama. Such nanostructure should play a very important role in their super-hydrophobic and self-cleaning characteristic.展开更多
Many biological surfaces possess unusual micro-nano hierarchical structures that could influence their wettability, which provide new methods for the construction of novel materials. In this work, silver nanoparticles...Many biological surfaces possess unusual micro-nano hierarchical structures that could influence their wettability, which provide new methods for the construction of novel materials. In this work, silver nanoparticles were successfully coated on the surface of stainless steel needle by a simple electroless replacement reaction process between the AgNO3 solution and the activated stainless steel needle. After the replacement reaction, porous micro/nanostructures were formed on the surface of the stainless steel needle. By modifying long chains ofthiol molecules, the stainless steel needle exhibited good super-hydrophobic property with a contact angle greater than 150°. Moreover, the silver coated stainless steel needle （bionic needle） showed strong antibacterial activity against the gram-negative bacterium Escherichia coli （E. colO. By calculating the area of the inhibition zone against E. coil formed on agar medium, the antibacterial activity of the bionic needle with the contact angle of 152° is much better than that with the contact angle of 138°. The as-prepared bionic needle with both super-hydrophobie and antibacterial properties has the potential to be applied in modem medical devices.展开更多
A multi-dimension bionic super-hydrophobic surface was prepared by embedding nano-silicaon on the sandblasted aluminum surface. After surface modification by perfluoroalkyltriethoxysilame, the surface shows the simila...A multi-dimension bionic super-hydrophobic surface was prepared by embedding nano-silicaon on the sandblasted aluminum surface. After surface modification by perfluoroalkyltriethoxysilame, the surface shows the similar capability and structure of lotus leaves. the super-hydrophobic surface shows static contact angle as high as 173° and tilt angle as low as 2.5° for 6.5 μL water droplet.展开更多
文摘Many biological surface are hydrophobic because of their complicated composition and surface microstructure. Eleven species (four families) of butterflies were selected to study their micro-, nano-structure and super-hydrophobic characteristic by means of Confocal Light Microscopy, Scanning Electron Microscopy and Contact Angle Measurement. The contact an- gles of water droplets on the butterfly wing surface were consistently measured to be about 150 ? and 100 ? with and without the squamas, respectively. The dust on the surface can be easily cleaned by moving spherical droplets when the inclining angle is larger than 3 ?. It can be concluded that the butterfly wing surface possess a super-hydrophobic, water-repellent, self-cleaning, or “Lotus-effect”characteristic. The contact angle measurement of water droplets on the wing surface with and without the squamas showed that the water-repellent characteristic is a consequence of the microstructure of the squamas. Each water droplet (diameter 2 mm) can cover about 700 squamas with a size of 40 m×80 m of each squama. The regular riblets with a width of 1000 nm to 1500 nm are clearly observed on each single squama. Such nanostructure should play a very important role in their super-hydrophobic and self-cleaning characteristic.
基金This work is supported by the National Natural Science Foundation of China （Grant No. 50875108）.
文摘Many biological surfaces possess unusual micro-nano hierarchical structures that could influence their wettability, which provide new methods for the construction of novel materials. In this work, silver nanoparticles were successfully coated on the surface of stainless steel needle by a simple electroless replacement reaction process between the AgNO3 solution and the activated stainless steel needle. After the replacement reaction, porous micro/nanostructures were formed on the surface of the stainless steel needle. By modifying long chains ofthiol molecules, the stainless steel needle exhibited good super-hydrophobic property with a contact angle greater than 150°. Moreover, the silver coated stainless steel needle （bionic needle） showed strong antibacterial activity against the gram-negative bacterium Escherichia coli （E. colO. By calculating the area of the inhibition zone against E. coil formed on agar medium, the antibacterial activity of the bionic needle with the contact angle of 152° is much better than that with the contact angle of 138°. The as-prepared bionic needle with both super-hydrophobie and antibacterial properties has the potential to be applied in modem medical devices.
基金supported by NSFC (29774036200174048) and National 863 Project (NO. 2001AA334060) aswell as SKLPPC Foundation Joint Laboratory of Polymer Sciences & Materials
文摘A multi-dimension bionic super-hydrophobic surface was prepared by embedding nano-silicaon on the sandblasted aluminum surface. After surface modification by perfluoroalkyltriethoxysilame, the surface shows the similar capability and structure of lotus leaves. the super-hydrophobic surface shows static contact angle as high as 173° and tilt angle as low as 2.5° for 6.5 μL water droplet.
基金National Natural Science Foundation of China(60774092,60872096)National High Technology Research and Development Program of China(2007AA11Z227)Research Fund for the Doctoral Program of Higher Education of China(20070294027)
