Hydrophobic cellulose fiber surfaces modified with 2,2,3,3,3-pentafluoropropylmethacrylate (FMA) by vapor-phase-assisted photopolymerization

We report a simple method to produce a hydrophobic surface created by continual vapor-phase-assisted surface photopolymerization (photo-VASP) of 2,2,3,3,3-pentafluoropropylmethacrylate (FMA), which affords control over the chemical and physical properties of unique substrate surfaces without inducing any morphological changes. The photo-VASP approach was able to modify the surface of cellulose fiber substrates such as a typical, complicated, flexible and soft substrate while maintaining their original properties, imparting superior water repellency without compromising the original tactile nature of the material. The substrate surface was consecutively exposed to the vaporized initiator and monomer FMA under ultraviolet irradiation to start photopolymerization, resulting in selective coating of the irradiated surface with polymer chains. The cellulose fibers coated by the thin polymer layer retained their original tactile nature and demonstrated superior water repellency, with a controlled static contact angle >130°. A new approach, vapor-phase-assisted surface photopolymerization (photo-VASP), was investigated to control the chemical and physical properties of complicated and delicate cellulose fabric surfaces. In this approach, a gaseous initiator was adsorbed on cellulose fibers, followed by photo-VASP of a fluoromonomer, 2,2,3,3,3-pentafluoropropylmethacrylate, under ultraviolet irradiation. Photo-VASP proceeded smoothly on the cellulose fiber surfaces to result in a thin coating showing a superior hydrophobic property.