Recently, Song Dongpo's research group of Tianjin University successfully developed photonic crystal pigments with beautiful structural colors. This new type of photonic pigment has the advantages of good biosafety and biodegradability, and is expected to bring disruptive technological innovation to the beauty industry. This achievement has been published in the authoritative journal German Applied Chemistry. It is reported that the project has been supported by the national key R&D plan and the National Natural Science Foundation of China.

In daily life, plastic microbeads are often used as fillers, film formers, thickeners and suspensions in nail polish, facial cleansers, sunscreens, liquid foundation and other products. After people use it, the plastic beads can easily be discharged into the ocean through the sewer, inhaled by marine organisms, and then enter the human body through the food chain. Therefore, it is urgent to develop non-toxic and biodegradable plastic bead substitutes.

Song Dongpo's research group has successfully developed photonic crystal pigments with beautiful structural colors based on the "orderly spontaneous emulsification principle". This new type of photonic pigment is made of biodegradable polyester materials such as polylactic acid. The photonic bead can perfectly replace the plastic bead, removing dead skin cutin and massaging skin.

The team selected typical aquatic organisms of different trophic levels such as Escherichia coli, Chlorella pyrenoidosa, Daphnia magna and zebrafish for rigorous environmental safety assessment. The experimental results show that the new photonic crystal pigment does not show any toxicity and has no adverse effect on the behavior of the above organisms, which proves that this kind of material can be used in cosmetics and other industrial products and is environmentally friendly.

It is particularly worth mentioning that the internal nanostructure of this new photonic pigment is "opal structure", which can form a "structural color" similar to butterfly wings and peacock feathers. The "structural color" has the characteristics of beautiful and lasting, and can respond to color change. Under different light angles, it can reflect different colors, thus producing a color change effect that traditional pigments do not have.

"This new type of photonic pigment is expected to widely replace non degradable plastic beads and artificial pigments in cosmetics and personal care products, as well as nano titanium oxide in sunscreens as ultraviolet reflectors." Song Dongpo said, "After being discharged into the water, it can spontaneously degrade into harmless lactic acid within a few months, which will not have a negative impact on the aquatic ecosystem, and will largely solve the environmental pollution problem caused by the use of cosmetics." Reporter Chen Xi Correspondent Jiao Defang