2013, Vol.25, No.2

Textile Coloration and Finishing KCI Impact Factor : 0.0

pISSN : 1229-0033 / eISSN : 2234-036X
https://journal.kci.go.kr/ksdf

Rhodamine dyes have been studied in various scientific areas due to their excellent photophysical properties. In particular, these rhodamine dyes are one of the most famous fluorophores as signal unit in chemosensor study. This is related to spirolactam ring system in rhodamine dyes. When the spirolactam ring is closed, there is nonfluorescence and colorless. Whereas, ring-opening of the corresponding spirolactam induces strong fluorescence and color. These absorption and emission changes are related to structural changes as well as electron energy potential levels such as HOMO and LUMO values. In this study, two different structures of rhodamine 6G hydrazide depending on the spirolactam ring system were investigated using absorption measurement, electrochemical measurement and computational calculations.

The electrochemical study has been enjoyed in many areas of chemistry. Through this approach using electrochemical measurement, empirical HOMO and LUMO values can be calculated by three methods such as absorption measurement, cyclicvoltammetry and computational calculations. In this study, 1,3-bisdicyanovinylindane was prepared and investigated toward its optical properties. The absorption intensities were changed depending on changes of pH. These absorption changes are induced by resonance form of 1,3-bisdicyanovinylindane. The electron delocalization in π system is related to the resonance form. In according to this electron density distribution and HOMO/LUMO values of 1,3-bisdicyanovinylindane were simulated and calculated by Material Studio 4.3, absorption measurement and cyclicvoltammograms. The 1,3-bisdicyanovinylindane is one of the most attracted acceptor units in D-π-A system. This attempt is useful to determine more detailed characteristics of the energy potentials.

Poly(acrylonitrile) (PAN) nanofibers containing different amounts of titanium dioxide (TiO2) have been prepared by electrospinning technique. Photocatalytic activity of these electrospun PAN/TiO2 nanofibers and the effect of TiO2 content on the photocatalytic efficiency of PAN/TiO2 nanofibers have been evaluated by monitoring the photodecomposition of fluorescein dye, rhodamine B and methylene blue under UV irradiation with respect to irradiation time. Moreover, the effect of hydrogen peroxide (H2O2) on the photocatalytic behavior of PAN/TiO2 nanofibers has also been investigated. The results showed that PAN/TiO2 nanofibers are effective photocatalyst and their photocatalytic efficiency increases with the increase of TiO2 content in the PAN/TiO2 nanofibers. It is also observed that the presence of H2O2 significantly enhances the photocatalytic ability of PAN/TiO2 nanofibers. The morphology and the photocatalytic behavior of the PAN/TiO2 nanofibers containing different amounts of TiO2 nanoparticles have been investigated by field-emission scanning electron microscopy (FE-SEM) and UV/Visible spectroscopy, respectively.