Preparation of hydrophobically modified cotton filter fabric with high hydrophobic stability using ARGET-ATRP...

This paper reports on the hydrophobic modification of cotton fabric grafted with 1-octadecene via an activators regenerated by electron transfer (ARGET) atom transfer radical polymerization (ATRP) mechanism. Particularly, the activation treatment of raw cotton fabric, its influence on the graft-copolymerization by the ARGET-ATRP method, along with the super-hydrophobicity and hydrophobic stability of the modified cotton fabric are discussed. Furthermore, the microstructure and elemental variation were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and the energy dispersion spectrum (EDS) technique. The results show that chemical activation of the raw cotton fabric can significantly improve the follow-up hydrophobic modification process. Specifically, the contact angle of the hydrophobically modified cotton fabric increased to 145° after activation, and thus, this fabric presents more stable hydrophobicity (corresponding to a 5.5% contact angle attenuation) than a non-activated fabric. The hydrophobic modification reaction was carried out using a chemically optimum stoichiometric ratio of m(CuBr₂) : m(C₉H₂₃N₃) : m(C₂H₅OH) : m(C₁₈H₃₆) : m(C₆H₈O₆) = 0.015 : 0.052 : 17.9 : 2.4 : 0.05, at a temperature of 30-55 °C over 8 h. Furthermore, the SEM and AFM images revealed that more copolymer micro/nano-level particles were present on the surface of the fibers of the hydrophobically modified cotton fabric, indicating that the hydrophobic property and stability of the cotton fabric increase with the grafting density on the cotton fabric.