FT-IR spectra of PUF, SVT-PUF and SVTPUP@ZnONPs are shown in figure 1A. The characteristic absorptions peaks of PUF were observed at 3733-3131 cm-1 (NH, OH), 2977&2877 cm-1 (CH aromatic and aliphatic), 1712 cm-1 (CO) and 1646 cm-1 (C=C). The broadband of NH and OH groups were shifted from 3733-3131 cm-1 to 3800-2740 and 3421-3112 cm-1 for SVT-PUF and SVTPUP@ZnONPs spectra, respectively. While the CH, CO and C=C groups were shifted to 2740 & 2964/2859, 1750&1702 and 1630&1641 cm-1.
In SVT-PUF spectrum, the new bands for N=C=S, C=N and C-S groups were observed at 2070, 1510 and 640 cm-1. While the new bands for N=C=S, N=C and Zn-O were developed at 2075, 1540 and 433 cm-1 in SVTPUP@ZnONPs spectrum. The broadband of NH/OH was shifted to 3559-3170, 3567-3139 and 3475-3124 cm-1 in spectra of SVTPUP@ZnONPs:Br.G, SVTPUP@ZnONPs:To.B and SVTPUP@ZnONPs:Tr.B (Fig. 1B).
Also, the band of N=C=S was shifted to 2086, 2078 and 2086 cm-1 and the Zn-O was shifted to 420, 416 and 455 cm-1. The CH aromatic, CH aliphatic, CO and C=C were observed at 2969, 2877, 1720 and 1650 cm-1 for SVTPUP@ZnONPs:Br.G, SVTPUP@ZnONPs:To.B and SVTPUP@ZnONPs:Tr.B. Figure 1 The electronic spectra of PUF, SVT-PUF and SVTPUP@ZnONPs were tested using Nujol mulls method (Emara et el., 2011). The characteristics of absorption band of PUF was observed at 213-361 nm due to the ? ? ?* and n ? ?* transition (Fig. 2).
This band was shifted from 213-361 nm to 212-398 nm (red shift) after coupling with vanillin then was shifted to 224-335 nm (blue shift) after coupling with zinc oxide nanoparticles. It indicates the formation of SVT-PUF and SVTPUP@ZnONPs, respectively. The characteristic band of SVTPUP@ZnONPs spectrum was shifted in the spectra of SVTPUP@ZnONPs:Br.G, SVTPUP@ZnONPs:To.B and SVTPUP@ZnONPs:Tr.B from 224-335 to 224-363, 224-363 and 224-363 nm (red shift) after sorption of Br.G, To.B and Tr.B dyes.
