Principal Component Analysis of the Effect of Batch Variation, TiO₂ Content and Reduction Temperature on the Surface Energy of TiO₂/Graphene Oxide Membranes upon UV-C Activation

In this work principal component analysis (PCA) was used to study the effect of batch, reduction temperature, TiO₂ content and UV-C irradiation on the surface energy, -polarity and interlayer spacing of photoactive TiO₂/GO composite membranes. Two PCA models were successfully developed. The first PCA model shows a negative correlation between reduction temperature and d-spacing. Less hydrophilic TiO₂/GO membranes were obtained at 160 °C compared to membranes reduced at 140 °C. Also, the surface polarity and surface energy were significantly enhanced by the addition of higher TiO₂ content. The second model explain the effect of UV-C activation on the surface energy of the TiO₂/GO composite membranes. For the GO membranes containing TiO₂ a significant increase in surface energy and -polarity was observed after UV-C activation. Moreover, a positive correlation between the TiO₂ content and surface energy after UV-C activation was observed. Higher TiO₂ content results in higher surface energy. GO batches prepared by different groups was not found to significantly affect the properties of the TiO₂/GO composite membranes suggesting that the preparation method is relative robust.