Superhydrophobic and breathable coatings on polyester fabrics
Lowering room temperature often requires the consumption of a significant amount of energy, especially when air-conditioners are used in the summer. Deep colour and infrared-reflective pigments (IRP) can reflect solar energy directly, and play an important role in space cooling. IRP can be applied to external walls, road, textiles, and so on.
However, dust is easily absorbed onto the surface of textiles, thus gradually leading to a reduction in their infrared reflectance. In a new work, IRP mixed with fluoride-free hydrophobic fume SiO2 nanoparticles (NPs) were added in ethanol to form a uniform suspension. Superhydrophobic (SH) coatings on polyester fabrics were prepared by orderly dipping coating the fabrics in adhesive solution and IRP/SiO2 suspension. The diluted adhesive not only ensured the mechanical stability of the SH surfaces against 30 cycles of sandpaper abrasion tests, but also imparted the textiles with good permeability.
The SH surfaces also exhibited high infrared reflectance and heat insulation property. Moreover, these characteristics were stable over 30 days in the outdoor environment. The researchers believe that such deep coloured, breathable, infrared-reflective and SH textiles can be used as roof of some automobiles to reduce air-condition energy consumption in summer.
The study has been published in Progress in Organic Coatings, Volume 147, October 2020.