Effect of reaction duration in the formation of superhydrophobic polymethylsilsesquioxane nanostructures on cotton fabric

The shape and size of the surface roughness induced by nanostructured materials have a significant effect on the wetting behavior of superhydrophobic surfaces. In this work, the effect of organosilane reaction duration on the formation of polymethylsilsesquioxane (PMSQ) nanostructures on cotton fibers surface has been investigated. The reaction was performed in methyltrichlorosilane (MTCS) solution at different duration time. The surface morphology and surface chemistry were investigated with scanning electron microscopy (SEM), attenuated total reflectance Fourier-transform infrared (ATR-FTIR) and energy dispersive X-ray (EDX) spectroscopy. The wetting properties of fabrics were elucidated by means of contact angle (CA) goniometry and sliding angle (SA) measurements. The results revealed that reaction duration has a significant effect on the morphology of nanostructures and also their covering density, which can influence the hydrophobic state of the surface. For fabrics with fine nanogrooves and low surface coverage, adhesion between droplets and the surface is high so that droplets cannot slide off even when the fabric was turned upside down ('sticky' surface) whereas for the fabrics with the high area density of the entangles nanofilaments, adhesion is low and droplets can roll off by tilting the plate ('slippery' surface). Mechanical properties of fabrics as well as washing durability were carried out. These findings would be helpful in understanding the role of the surface coverage and morphology of nanostructures on the superhydrophobic behavior of fabrics and guiding the design of perfect artificial superhydrophobic textiles for extended practical application.