The superhydrophobic surface can be prepared by two methods; one is by reducing the surface energy, and the other is by constructing a micro-nano rough structure. To achieve high superhydrophobic performance in terms of durability, the firm combination of hydrophobic coating and substrate is particularly important. Here, we use polydimethylsiloxane (PDMS) as a low surface energy monomer, water-borne polyurethane (WPU) as a dispersing aid, and use high-power ultrasound to disperse PDMS in water to make emulsion. The polyester matrix is etched by atmospheric plasma, dipped in PDMS emulsion, dried, and finally baked to induce PDMS on the surface of polyester fiber to cross-link into film. A series of tests on the self-cleaning polyester fabric prepared by this method show that when the concentration of PDMS is 8 g/L and the mass ratio of PDMS to WPU is 20:1, the water contact angle (WCA) reaches the maximum value of 148.2°, which decreases to 141.5° after 200 times of washing and 138.6° after 5000 times of rubbing. Before and after PDMS coating, the tensile strength of polyester fabric increases from 489.4 N to 536.4 N, and the water vapor transmission decreases from 13,535.7 g/(m2·d) to 12,224.3 g/(m2·d). This research is helpful to the large-scale production of self-cleaning polyester fabric. In the future, on the basis of this research, we will add functional powder to endow self-cleaning polyester fabric with higher hydrophobicity and other properties.
Keywords: atmospheric pressure plasma; polydimethylsiloxane; self-cleaning polyester; waterborne polyurethane.