Fire-Resistant Inorganic Analogous Xuan Paper with Thousands of Years’ Super-Durability

Xuan paper is a unique kind of high-quality paper originating in ancient China; it enjoys a great reputation as "the king of paper that lasts for 1000 years" and was inscribed on the Representative List of the Intangible Cultural Heritage of Humanity by the Educational, Scientific and Cultural Organization of the United Nations in 2009. Xuan paper is the best material carrier for conveying the artistic expression of calligraphy and painting. The raw materials for Xuan paper are closely related to the geography of Jing County, Anhui Province in China and thus in acute shortage. The handmade production of Xuan paper involves more than 100 steps and takes nearly two years, leading to low output and high cost. Xuan paper with an organic origin usually suffers from degradation, yellowing, and deteriorating properties during the long-term natural aging process. Furthermore, the most lethal problem of Xuan paper is its high flammability. During humanity's long history, numerous precious calligraphy and painting works and books were ruined by fire. Herein, we report a new kind of highly flexible inorganic analogous Xuan paper based on ultralong hydroxyapatite nanowires with excellent fire resistance, thousands of years' superdurability, unique ink wetting, high whiteness, and excellent antimildew qualities benefiting from its 100% inorganic origin, which are far superior over traditional Xuan paper. The inorganic analogous Xuan paper can be well preserved with no obvious deterioration in properties even after simulated aging for 3000 years. The most attractive merits of inorganic analogous Xuan paper are its excellent nonflammability and high thermal stability, which can well safeguard precious calligraphy and painting works, documents, and books for a very long period of time without the fear of being destroyed by fire or yellowing. The production process of inorganic analogous Xuan paper is environmentally friendly and simple with only a few steps in contrast to more than 100 steps for traditional Xuan paper, and it is highly efficient and takes only 2–3 days instead of the about 2 years for traditional Xuan paper. The future commercialization of inorganic analogous Xuan paper will solve the problems of traditional Xuan paper such as a severe shortage of geography-specific raw materials, superlong production cycle, yellowing, and high flammability and extend its applications to fire-resistant books, documents, and archives in addition to the calligraphy and painting arts.