Hydrophobic sol-gel coatings based on polydimethylsiloxane for self-cleaning applications

Self-cleaning coatings are of immense importance for various technological applications. In this work, we report the formulation and characterization of erosion-resistant self-cleaning coatings. Hydroxyl-terminated polydimethyl siloxane (PDMS) was added to tetraethylorthosilicate (TEOS) based sol-gel network as a functional additive. The coatings showed a low sliding angle (less than 10 degrees) when the static water contact angle was around 112 degrees. Spectrophotometric measurement was used to quantify the self-cleaning efficiencies after subjecting the samples to artificial dirt spray and water cleaning. The effect of filler content on the self-cleaning efficiency was discussed. The mechanical properties and durability of the coatings were also studied. Based on the current work, we have successfully demonstrated the concept of self-cleaning coatings without forming superhydrophobic surfaces. (C) 2015 Elsevier Ltd. All rights reserved.