Recent Progress on Bio-Inspired Highly Scattering Polymeric Materials

Highly scattering materials have widespread applications in daily life. Achieving efficient light scattering often requires the use of high-refractive-index inorganic materials, such as titanium dioxide. However, the production of titanium dioxide particles leads to serious environmental pollution, and since 2020, they have been classified by the EU as a Category 2 carcinogen for inhalation. Therefore, it is urgent to develop safer materials for preparing highly scattering products, such as polymers. Recently, scientists have made remarkable progress in the preparations and applications of highly scattering polymeric materials through mimicking the delicate internal structure of white-appearing creatures found in nature. This viewpoint summarizes the current progress and applications in highly scattering polymeric materials and forecasts future trends. Unlike previous reviews, this work systematically evaluates the use of natural polymers─specifically cellulose and its derivatives─for producing highly scattering materials and their corresponding applications in optoelectronics, wearable devices and passive radiative cooling.