Different compositions of the phthalocyanine dye were tested in order to find the optimum amount of sensitizer to get the highest activity during the photocatalytic tests.
In order to find out the optimum amount of phthalocyanine dye required to sensitize effectively the Ti[O.sub.2] material, a series of tests varying the volume (0.5, 1.0, 2.5, 5.0, 7.5, and 10 mL) of dye solution in DMSO (6 [micro]M) were carried out using the asymmetric phthalocyanine complex.
The incorporation of the AZnPc dye does not modify the crystal structure of the Ti[O.sub.2]-DP25 material, as can be seen by comparing the diffractograms in Figure 2, and this can be rationalized in terms of the very low quantity of phthalocyanine dye in the DP25-Pc composite.
In order to improve the activity of Ti[O.sub.2]-DP25 in the visible range, sensitization with a functional phthalocyanine dye was considered and a series of preliminary tests using four different Zn[Pc.sub.s] was carried out.
Polyethylene oxide [PEO.sub.10,000] was added to reduce the aggregation of the phthalocyanine dye and consequently enhance their absorption in aqueous medium (Ng 2003).
Figure 10 shows a comparison of photocatalytic activities of bare Ti[O.sub.2], N-Ti[O.sub.2] and N,F-Ti[O.sub.2] for the photocatalytic degradation of phthalocyanine aqueous solution at ambient temperature; [C.sub.t] and [C.sub.o] denote the reaction and initial concentration of the phthalocyanine dye in the system, respectively.
The mechanism of the photocatalytic degradation of the phthalocyanine dye by the prepared photocatalysts needs further investigations.
Decolorization of the phthalocyanine dye reactive blue 21 by turnip peroxidase and assessment of its oxidation products.
Phthalocyanine dye reacts quicker to the writing laser than dyes found in most CD-Rs on the market, Delkin notes, thus making sharper pit edges and making the CD-R easier to read by CD drives.
Phthalocyanine dye is more responsive to the writing laser; cleaner, better-defined pits are created, resulting in fewer errors when burning data to the CD.
The stability of phthalocyanine dye makes it more resistant to damage from heat sources.
Although azo dyes represent about 60% of all reactive dyes used by the textile industry, other classes of reactive dyes, namely anthraquinone and phthalocyanine dyes
, are also extensively used either as primary or secondary dyes in commercial trichromatic dyeing formulations [6, 7].