A novel and inexpensive technique for creating superhydrophobic surfaces using Teflon and sandpaper

Abstract

Considerable efforts have been spent over the last decade developing hydrophobic surfaces exhibiting very large contact angles with water. Many of these methods require complex and expensive fabrication techniques. We demonstrate that sanding Teflon can produce superhydrophobic surfaces with advancing contact angles of up to 151 • and contact angle hysteresis of less than 4 •. Furthermore, we show that a wide range of both advancing contact angles and contact angle hysteresis can be achieved by varying the grit size of the sandpaper, allowing for future hysteresis and contact angle studies. Scanning electron microscopy images of the roughened surfaces depict the range and amplitude of length scales imparted on the surface by the sandpaper, which leads to deeper understanding of the state of wetting on the surface.

Enhancing Water and Oil Repellency of Teflon Surface By Imparting Micro-Rough Structures Using Simple One-Step

“…It shows the CAs of the three liquids on the physically modified Teflon surface by wet mechanical sanding using a wide range of sandpaper GS. It can be noticed that the surface roughness of the Teflon surface has enhanced its repellency toward the three tested liquids (Nilsson 2010). This is in accordance with Wenzel model which implies that the increase in roughness amplifies the wetting properties of solid surfaces.…”

“…Two different surfaces with similar CAs can promote different dynamic behavior of droplets depending on their CAH; the difference between advancing CA ( ) and receding CA ( ). Lotus effect (Nosonovsky et al, 2009;Cheng et al, 2006) is the best example of surfaces with high CA but small CAH, small SA, while Petal effect (Feng et al, 2008;Bhushan et al, 2010) is the best example of high CA and large CAH as well, and consequent large SA. For the liquid droplet to slide by the effect of its weight ( ) after tilting the substrate (SA) by a specific angle of ( ), can be expressed as (Xiu et al, 2008;Hsieh et al, 2009):…”

“…The past decade has witnessed numerous studies in the fabrication of water super-repellent surfaces, super hydrophobic surfaces with CA > 150º, using various techniques and materials (Bhushan and Nosonovsky, 2007;Gao and Macarthy, 2006;Lafuma and Quere, 2003;Nilsson et al, 2010;Patankar 2009). Several studies were conducted for the fabrication of surfaces that could be super-repellent towards water and a diverse range of low surface tension liquids such as organic liquids, superomniphobic surfaces, but are very limited (Cao et al, 2008;Chien-Te et al, 2009;Deng et al, 2012;Tuteja et al, 2007).…”

“…For this purpose, there has been very limited number of studies which mainly focused on imparting super repellency only toward water. Dry mechanical sanding of Teflon surface and its water repellency properties were first conducted by Nilsson et al (Nilsson 2010). In their study, micro scale roughness was imparted to Teflon surface using grit designation of 40-600, obtaining water CA as high as 150° and CAH as low as 4°.…”

Metal oxide thin films and nanostructures for self-cleaning applications: current status and future prospects

“…Surface topography plays a major role in the hydrophobic behavior of the surfaces. Techniques such as lithography, etching are effective to fabricate surfaces with different topology such as square pillars, parallel grooves [82][83][84][85][86][87][88][89][90][91][92]. Typical examples of polymer base superhydrophobic surfaces are shown in Figure 10.…”