ColMhyBio

Nowadays, if synthetic colorants still present a wider range of colors and are cheaper than natural colorants, they remain highly polluting. Their production based on petrochemicals and their use in the coloring industry have a huge impact on the environment and our health. Therefore, replacing polluting synthetic colorants by bio-based colorants is today the main priority of various industries e.g. coating, painting, textile, cosmetic and construction. However, many issues, including color range, stability, tinting strength and costs need to be solved before setting a competitive and sustainable alternative to synthetic colorants. Inspired by the biomineralization and pigmentation mechanisms occurring in sea urchin spines the ColMhyBio project proposes to produce a large color panel of bio-based hybrid colorants having chemically- and photo-stable colors. The skeletal elements of sea urchins, in particular their spines exhibit a wide range of intense, homogeneous and long-lasting colors ranging from purple to green. These remarkable color properties are likely due to the occlusion of a mixture of different polyhydroxylated-naphthoquinones (PHNQ) molecules, the pigment of the spines, within the inorganic CaCO3 host. In this project, we will first develop eco-friendly protocols for the extraction of the PHNQ molecules from recycled colored spines and from red-spherule cells in which they are biosynthesized. Different bio-inspired syntheses will be then developed to encapsulate the PHNQ molecules within a crystalline CaCO3 inorganic host during the crystallization of an amorphous CaCO3 phase (ACC). The PHNQ’s incorporation during ACC crystallization is expected to lead to strong inorganic-organic interactions likely responsible for the color variations and stability. Thus, a chart of new bio-based hybrid colorants exhibiting a large palette of chemically- and photo-stable colors devoted to a sustainable biocoloring industry will be produced.