When Traditional Chinese Pigments meet Stellera chamaejasme L. on Qinghai-Tibet Plateau: Stability or Fading upon Exposure to Light?
Abstract
Traditional architectural paintings, particularly those in the Qinghai-Tibetan Plateau, face significant color fading due to high UV radiation, threatening their artistic and cultural value. This study investigates Stellera chamaejasme L., a native plant, as a natural UV protectant for traditional pigments, including cinnabar, orpiment, realgar, malachite, and azurite. UV-photoaging tests revealed that Stellera chamaejasme L. enhances UV absorption, significantly improving pigment stability. UV-vis spectroscopy confirmed its strong photoprotective effect, while XRD and FTIR analyses demonstrated its ability to preserve crystal structures and inhibit carbonyl group decomposition. Chromatic variation (ΔE) measurements showed that pigments treated with Stellera chamaejasme L. exhibited 48.1–75.7% less fading compared to untreated samples, with notable efficacy for cinnabar, orpiment, and realgar. Due to its abundance in the Qinghai-Tibetan Plateau, ease of application, and light stability, Stellera chamaejasme L. offers a sustainable, eco-friendly solution for conserving traditional architectural paintings. This research provides a promising green approach to mitigating UV-induced degradation in cultural heritage.