Bio-friendly stable organic-inorganic hybrid pigments based on carminic acid and porous minerals: acid/base allochroic behavior and UV-stabilizing effects on ethylene-norbornene copolymer matrix
Year: 2022
Type: article
Abstract: This paper presents the design of natural, high-performance hybrid pigments consisting of carminic acid incorporated on different porous minerals. Raw sepiolite, palygorskite, hydroxyapatite, and vermiculite clays were employed as effective and eco-friendly carriers for carminic acid stabilization. The structure and physico-chemical properties of the prepared hybrid pigments were determined by 13C NMR, XRD, TEM, TGA and UV-Vis analysis. The carminic acid dye was found to be capable of interacting with metal ions present in the inorganic carriers (Mg2+, Al3+, Ca2+), leading to the formation of organic-inorganic pigments with considerably improved thermal and chemical stability. Importantly, the carminic acid hybrid pigments also proved stable and efficient acid-base regulators, changing color after just a few minutes of exposure to HCl or NH3 vapors. Application of the designed hybrid pigments in ethylene-norbornene copolymer increased the photo-stability and reduced the flammability of the colored polymer composites. This study paves the way for efficient production of colorful, eco-friendly, organic-inorganic pH indicators and stabilizers for elastomers based on carminic acid.
Language: English
Subfield: Inorganic Chemistry
Field: Chemistry
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $2,990
OpenAlex ID: W4285097779