Durable and recoverable hydrophilicity of polyethylene terephthalate fabric prepared with plasma selective etching

Durable delustered PET (PET-TiO2) fabric super hydrophilic surface has been obtained by plasma selecting etching. The aging effect of their hydrophilicity after plasma treatment has been investigated with storage time. After Ar/O2 radio frequency (RF) plasma treatment for only 1 min, PET-TiO2 fabric showed water contact angle of 0o. After 10 month storage time, it keeps its water contact angle below 75.7o. Further more, with Xenon light irradiation for 10 min, it is firstly found that it has well-recovered water contact angle to 5°. While the contact angle of PET fabric for 7 min returns to 123.0° and its hydrophilicity disappeared almost completely and showed no response to Xenon light irradiation. The water absorption rate of 7 min plasma treated PET-TiO2 fabric increased by 57.54%. By field emission scanning electron microscopy (FE-SEM), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction analysis(XRD) measurement, waviness structure of humps and ridges with irregular particles or pits were found on the plasma treated PET-TiO2 fabric surface and increased Ti atomic percentage was observed. It is verified that TiO2 particles inside PET-TiO2 fiber have been exposed to its surface by plasma selective etching of its organic component. It suppresses the aging effect and is characterized with durable and recoverable hydrophilicity. This one step, quick, green, and cost-reasonable manufacture method has a practical application for durable superhydrophilic surfaces.