Effect of Nanometric-Scale Roughness on Slip at the Wall of Simple Fluids

• DOI: 10.1021/la060061w
• Publication Date: 2006-06-30T16:44:14Z
• Authors: Tatiana Schmatko; Hubert Hervet; Liliane Léger
• Keywords: Hexadecane; Slippage; Microscale chemistry

It is commonly acknowledged that roughness decreases the aptitude of simple liquids to exhibit flow with slip at solid interfaces. Most available studies have, however, been conducted on substrates for which both surface chemistry and were varied simultaneously, making it difficult identify their respective role wall slip. To overcome this difficulty, we have developed a series surfaces formed by grafting hyperbranched polymeric nanoparticles smooth, dense, self-assembled monolayer SiH-terminated short poly(dimethylsiloxane) oligomers, allowing us vary independently density, height, width grafted nanoparticles, thereby parameters, while keeping similar chemistry. On such substrates, boundary condition velocity hexadecane has characterized through near-field laser velocimetry. We demonstrate decreasing wavelength fixed height strongly slip, increasing aspect ratio also dramatically affects slippage.