Abstract:
Reactive Black 5 (RB5) dyes are a group of azo dyes that are widely used for dyeing
fabrics. The purpose of this study was to determine the effect of the pH used in
different variations, namely at pH 4,5, pH 5,5 and pH 6,5 on the resulting RB5 color
spectrum, as measured by its absorbance of visible light. Based on this study, there
were no significant differences observed in the visible light absorbance maximum
wavelengths of RB5 at different pHs. The RB5 visible light absorbance spectrum
resulted in a broad peak, with an approximate absorbance maximum at 600 nm at pH
4,5, pH 5,5 and pH 6.5. Although not causing any shift in the maximum absorbance
wavelength, there was a difference in the resulting absorbance intensity at different
pH. So, it can be concluded that the use of pH variations between pH 4,5 to pH 6,5
can cause differences in absorbance intensity, but no shift in RB5 maximum
absorbance wavelength.
