The Effect of cellulose oxidation on interfacial bonding of nano-TiO2 coating to flax fibers

In this study, flax fibers were oxidized in order to improve the interfacial adhesion of cellulosic fibrils to a TiO2 coating. The TiO2 coating was created on the flax fiber by a Sol-Gel dip-coating technique. The effect of cellulose oxidation and the consequent TiO2 grafting was studied on cellulose crystalline structures using X-ray diffraction. X-ray photoelectron spectroscopy was used to compare the reactivity of TiO2 Sol with oxidized and non-oxidized cellulosic fibers. In addition, transmission electron microscopy and atomic force microscopy were applied to characterize the quality of the interface between the fibers and TiO2 coating. Finally, the effect of cellulose oxidation on the mechanical properties of TiO2-grafted flax strands was investigated by tensile tests. The results showed that the oxidation increased significantly the reactivity of the cellulosic surfaces with TiO2 Sol. This method was able to increase the quality of the interface between flax fiber and TiO2 coating, which improved the thermal resistance of the fibers. Eventually, the oxidation of the fiber together with the TiO2 grafting increased significantly both ductility and maximum tensile strength of the flax strands.