Fabrication and wettable investigation of superhydrophobic surface by soft lithography

Abstract

The natural hydrophobicity of surfaces can be enhanced if they are microtextured due to air trapped in the structure, which provides the deposited drop with a composite surface made of solid and air on which it is rest. Here, a series of grating microstructure surfaces with different parameters have been designed and fabricated by a novel soft lithography. The water contact angles (WCA) on these rough surfaces are measured through optical contact angle meter. The results indicate that all the WCA on the surfaces with grating microstructures are up to 150°; WCA increases and the hydrophobic performance also enhances with the decrease of the ridge width under the other fixed parameter condition; Experimental data obtained basically consists with the Cassie’s theoretical prediction. The effects of geometric parameters of the microstructures on wettability of the grating sufaces are investigated.

Keywords

microtexture / superhydrophobicity / composite surface / wettability / bearing lubrication

References

[1] Furstner R., Barthlott W., Neinhuis C., . Wetting and Self-cleaning Properties of Artificial Superhydrophobic Surfaces[J]. Langmuir, 2005, 21: 956-961.

[2] Cheng Y., Rodak D. E. Is the Lotus Leaf Superdydro-phobic[J]. Appl. Phys. Lett., 2005, 86(14): 144 101-144 103.

[3] Sun T. L., Feng L., Gao X. F., . Bioinspired Surfaces with Special Wettability[J]. Acc. Chem. Res., 2005, 38: 644-652.

[4] Blossey R. Self-cleaning Surfaces-virtual Realities[J]. Nat. Mater., 2003, 2: 301-306.

[5] Shiu J. Y., Kuo C. W., Chen P., . Fabrication of Tunable Superhydrophobic Surfaces by Nanosphere Lithography[J]. Chem. Mater., 2004, 16(4): 561-564.

[6] Vandencasteele N., Fairbrother H., Reniers F. Selected Effect of the Ions and the Neutrals in the Plasma Treatment of PTFE Surfaces: an OES-AFM-contact Angle and XPS Study[J]. Plasma Process. Polym., 2005, 2(6): 493-500.

[7] Pozzato A., Dal Zilio S., Fois G., . Superhydrophobic Surfaces Fabricated by Nanoimprint Lithography[J]. Microelectronic Engineering, 2006, 83: 884-888.

[8] Li B. J., Zhou M., Yuan R., . Fabrication of Titanium based Micro structured Surfaces and Study on Their Superhydrophobic Stability[J]. J. Mater. Res., 2008, 23: 2 491-2 499.

[9] Wu D., Chen Q. D., Xia H., . A Facile Approach for Artificial Biomimetic Surfaces with Both Superhydrophobicity and Iridescence [J]. Soft Matter., 2010, 6: 263-267.

[10] Cassie A. B. D., Baxter S. Wettability of Porous Surface[J]. Trans. Faraday. Soc., 1944, 40: 546-561.