Fig. 15

FTIR-2D imaging of unsoiled Azo Yellow Golden MSA mock-up, showing an area cleaned with Nanorestore Gel^® Peggy 6 hydrogel (a, b) (exposure time: 15 min) and an unsoiled control (c, d). For each area, the images besides the visible map show the corresponding 2D-FTIR maps, where the intensity of the negative band at the 1251 cm⁻¹ (C–O stretching of PVA, marked with an asterisk) was mapped. All maps are 700 × 700 µm². The corresponding FTIR spectra are shown in the right panel, and each spectrum relates to a single pixel (5 × 5 µm²) of the corresponding 2D imaging map