Preparation of titanium dioxide fibers as stationary phase in thin layer chromatography

Abstract

In this study, the electrospun fibrous titania were prepared via sol-gel process of titanium tetraisopropoxide and fabricated with electrospinning method. The electrospinning factors that affect the fibers morphology were studied. The electric potential, the distance between a needle and a collector, and the flow rate of the solution influenced the fiber size. At higher PVP:TiO2 ratio, the fiber diameter, the specific surface area and the pore size decreased. When calcination temperature was increased, fiber diameter and specific surface area decreased while the pore size increased and led to transformation of the titania from anatase to rutile. The electrospun fibrous titania had the average diameter range of 50-190 nm and the specific surface area of 2-34 m2/g. The electrospun fibrous titania was used as stationary phase in thin layer chromatography for separation of basic dye compounds which were methyl violet, methylene blue hydrate, and congo red, and compared with particulate silica stationary phase. The efficiency of dye separation using the electrospun fibrous titania TLC was better than the particulate silica TLC. In analysis at basic condition, retardation factors of positively charged methyl violet and methylene blue hydrate, on the electrospun fibrous titania TLC were higher than those on the particulate silica TLC. While retardation factor of negatively charged congo red, on the electrospun fibrous titania TLC was lower than that on the particulate silica TLC. In addition, the analysis time of the electrospun fibrous titania TLC was shorter than that of the particulate silica TLC.