Hydrophobicity, water moisture transfer and breathability of PTFE-coated viscose fabrics prepared by electrospraying technology and sintering process

Coating of PTFE on the fabrics is one facial method to obtain the hydrophobic/superhydrophobic property. However, the breathability of the PTFE-coated fabrics prepared by traditional methods (e.g., sputtering) is significantly affected. Electrospraying technology was able to create the pure PTFE coating layer on any substrates and the following sintering process is necessary to obtain the hydrophobic/superhydrophobic property. In this work, the PTFE-coated viscose fabrics were firstly prepared via electrospraying technology and then stabilized after 10 min sintering process with different temperatures ranging from 150 °C to 210 °C. The morphology, hydrophobicity, breathability, and water moisture transfer of the PTFE-coated viscose fabrics as well as the chemical compatibility between PTFE microparticles and viscose fabric were investigated. With increased sintering temperature, the PTFE coating layer on the viscose fabric became physically denser, which corresponded to the reduced breathability. Only when sintering temperature was equal to or higher than 190 °C, the stable hydrophobicity of PTFE-coated viscose fabric was found. When sintering temperature was increased from 190 °C to 210 °C, the contact angle hysteresis of the hydrophobic PTFE-coated viscose fabric decreased from 9.2° to 3.4° and the one-way water moisture transfer was enhanced.