Improving the hydrophobicity of polymers through surface modification and investigating its effect on surface damage resistance

Improving the hydrophobic property of polymers is advantageous in various applications such as automotive, aerospace, electronics, optical, packaging industries, household appliances, etc. Although hydrophobic surfaces can be used in wide range of applications, these surfaces are susceptible to wear and abrasion which may change the chemistry of the surface and consequently result in loss of hydrophobicity. As a result, mechanical durability/surface damage resistance remains a central concern for various applications. In this research, model polymers with smooth surface finish have been modified by introducing textures on their surfaces to primarily improve their hydrophobicity. Square pillar textures of varying length and pitch with fixed pillar height are introduced on each polymer surface via a hot embossing process. Water contact angle measurement is used to describe the hydrophobic property of both smooth and textured polymer surfaces. Improvement in hydrophobicity was observed when textures were added on smooth polymer surfaces. This improvement depends on geometric features of the square pillar textures. Additionally, scratch study on both smooth and textured samples shows a reduction in scratch coefficient of friction in the textured polymer samples compared to the smooth ones. However, the effect of surface texture on scratch-induced surface damage depends on scratch tip size