ABSTRACT
In this study, different pigments were exposed to Volatile Organic Compounds (VOCs), and their physicochemical properties were studied. The pigments chosen were: hematite, malachite, white-lead, cinnabar, gypsum. Two binders were tested too: animal glue and Arabic gum. Each pigment and binder was exposed to 50μl of each of the major pollutants separately (m-xylene, 1,2,4-trimethylbenzene, 1-methoxy-2-propyl acetate, hexanal, 2,2,4-trimethylpentane, nonane, 2-butanone oxime, octamethylcyclotetrasiloxane, dodecamethylcyclohexasiloxane, methanol, acetic acid, and formaldehyde). After one month of exposure, the excess of VOCs on the pigment was volatilized at 40°C, and the samples were analyzed by XRD, FTIR and UV-Vis. The stability of these pigments against most VOCs showed that the acids and aldehydes alter the structure of the pigments based on carbonates and sulfates. Alteration of color intensity has been observed in the malachite, in the presence of hexanal and acetic acid. Malachite, gypsum, and lead white showed changes in the crystalline structure when exposed to acetic acid. Spectrometric results showed that there are interactions of VOCs with different pigments.
