Conductive and photoactive properties of polyethylene terephthalate fabrics treated with nano TiO₂/nano carbon blacks

A polyethylene terephthalate (PET) fabric was pretreated by alkaline-hydrolyzation. Both the pristine and pretreated PETs were loaded with nano carbon blacks (CB1515 and CB156), mixtures of nano TiO₂ (NTO) and NCBs (CB1515 or CB156) using an impregnation method with sodium dodecyl sulfate as a dispersing agent. Citric acid (CA) and sodium hypophosphite (SHP) were also used as a cross-linking agent and a catalyst respectively in addition to the dispersant to load NTO+CB1515 and NTO+CB156 onto the PETs with and without pretreatment as comparisons. It is found that CB156 is more effective than CB1515 to decrease the electrical resistivity for all samples. The samples from the pristine PET have lower resistivities than those from the pretreated PET when NTO is added. However, this is reversed when NTO is not added. Use of CA and SHP can significantly lower the resistivity of samples in all cases by increasing the loading level and dispersion uniformity of NCBs and NTO in the fabrics. A synergistic effect of NCBs and NTO is found to increase UV absorption of the treated fabrics. The samples from the pristine PET loaded with NCBs and NTO were more active than those from the pretreated PET for the degradation of methylene blue. The activity can be increased by loading with NTO or by adding both CA and SHP and the former is more effective than the latter.