Hybrid elastomer-nanotube matrix for hydrophobic surface functionalization

Abstract

Surface functionalization studies for re-creating a ‘Lotus Leaf’ effect (super-hydrophobic) have been carried out for the past few decades, looking for the material which can provide high transparency, low energy surface, and high surface roughness. However, the conventional fabrication processes of super-hydrophobic surface proposed by the previous researchers were reported to be complicated. Therefore, in this research, we had created an alternative ways to produce near-super-hydrophobic surfaces using simplest processing routes with a controlled modification. The fabrication of polydimethylsiloxane/multi-walled carbon nanotubes (MWCNTs) hybrid thin film matrix on glass to produce near-super-hydrophobic surfaces is presented in this paper. There are three important parameters studied in producing hydrophobic surfaces based on the hybrid thin films; concentration of polydimethylsiloxane, concentration of MWCNTs, and droplet sizes, respectively. The study is carried out using polydimethylsiloxane of varied cross linker ratio (10:1, 30:1, and 50:1) with MWCNTs concentration of 1, 10, and 15 mg for 0.5, 2.0, 5.0, and 10 μl droplet sizes. The resulting hybrid elastomer-nanotube matrix thin films show that hydrophobicity increased with increasing cross linker ratio and MWCNTs percentage in the polydimethylsiloxane solution. A near-super-hydrophobic surface can be created when using 15 mg of MWCNTs with 50:1 cross linker ratio polydimethylsiloxane thin films, measured on 10 μl droplet size. The hybrid thin films produced can be potentially tailored to the application of biosensors, MEMS, and even commercial devices.

Keywords:

• polydimethylsiloxane (PDMS)
• multi-walled carbon nanotubes(MWCNT)
• hydrophobic surfaces
• contact angle measurement
• hybrid thin films

Acknowledgments

The authors acknowledge the contribution of Laboratory (TAREL), School of Microelectronic Engineering and Centre of Excellence Geopolymer and Green Technology (CEGeoGTech), Universiti Malaysia Perlis for providing necessary assistance for completing this research.