As the angle between incident light and observers becomes larger, the color of nail polish containing photonic pigment turns from red into blue.

Tianjin University has developed a new type of photonic crystal pigments, with vivid structural colors, biosafety and degradability elements promising to bring significant renovation to the cosmetic industry.

Although plastic microbeads are widely used in daily necessities, such as toothpaste, facial cleanser, and sunscreen, they may contribute to microplastic pollution.Therefore the development of innoxious and degradable alternatives has become a top priority for material scientists.

Based on the spontaneous emulsification mechanism, a research group led by Professor Song Dongpo at Tianjin University has successfully developed new biocompatible and biodegradable photonic crystal pigments. This promising pigment can be made from bio degradable polylactic acid as well as other polyester materials.

Biosafety is another advantage when compared to traditional microbeads. Song’s team has confirmed that the photonic pigments are environment-friendly after extensive experiments. They said that such materials have a great potential to be utilized in cosmetics products as well as other industrial products.

Importantly, the internal nanostructure of this new photonic pigment can produce structural colors that have long life time and shows iridescent color-changing properties.

“It’s hopeful that the new materials will replace non-degradable microbeads and artificial pigment in makeup and personal care products, since they can be degraded into nontoxic lactic acid when discharged into water, causing no adverse effect on the aquatic ecosystem,” Song said. This research project has been supported by National Key R&D Program of China and National Natural Science Foundation of China, he added.