Wettability Enhancement of Bio-Inspired Micro-Textured Polymeric and Carbon Surfaces

Wednesday, October 19, 2011: 3:53 PM
L100 E (Minneapolis Convention Center)
Chandra S. Sharma1, Kumar Abhishek2, Hari Katepalli2 and Ashutosh Sharma2, (1)Department of Chemical Engineering, Indian Institute of Technology, Hyderabad, Yeddumailaram, India, (2)Department of Chemical Engineering and DST Unit on Nanosciences, Indian Institute of Technology, Kanpur, Kanpur, India

Polymeric surfaces with enhanced wettability have been a subject of growing interest and research because of a wide variety of applications in fabricating anti reflective, low friction, water repellent and anti-biofoulant surfaces. Further, carbon surfaces with ultra hydrophobic response add some more applications in the list such as in Bio-MEMS, and microfluidics because of some intrinsic properties associated with carbon as a material itself. We present a simple and robust method to enhance the wettability of polymer surfaces by micro-patterning. The patterns found on two different leaves, Elephant creeper (Argyreia Nervosa) and Nasturtium (Tropaeolum Majus) which show superhydrophobic behaviour because of hairy and micro textured surfaces respectively were bio-mimicked by micro-molding technique in different polymers, polydimethylsiloxane, polystyrene, and resorcinol-formaldehyde (RF) gel. Bio-mimicked polymer surfaces because of roughness induced my micro-texturing shows significant the enhancement in the wettability characteristics. Moreover, since RF gel is a polymer precursor to carbon, micro-patterned RF gel surfaces yielded ultra-hydrophobic carbon surfaces upon pyrolysis.  The methodology presented here in this work can be easily applied for fabricating large area stable ultra-hydrophobic polymeric as well as carbon surfaces directly by biomimicking the patterns found on natural plant leaves. Furthermore, the nano-imprint lithography was also used to diversify this novel approach of fabricating the ultra-hydrophobic surfaces by transferring the leaf patterns on various other polymers like poly ethylene terephthalate and poly methyl methacrylate surfaces.

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See more of this Session: Biomimetic Materials II
See more of this Group/Topical: Materials Engineering and Sciences Division