Preparation And Properties Of Nanocomposite "Xuan Paper" Based On Ultralong Hydroxyapatite Nanowires

Paper,one of the most important inventions in ancient times,provided an important foundation for the spread of culture and greatly promoted the development of civilization.As the best inheritor of papermaking,Xuan paper is a unique art treasure in China and enjoys a high reputation at home and abroad.Xuan paper with the superior texture,durability and suitable characteristics for writing and painting plays an important role in the dissemination of culture and art.Xuan paper has won the reputation of “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 generally divided into unprocessed Xuan paper and processed Xuan paper.However,the surface of the commercial unprocessed Xuan paper has a large number of large-sized pores with a poor resistance to water,making the ink droplet easily spread during the writing and painting process.The commercial processed Xuan paper is prone to yellowing and brittleness during long-term storage,and the durability is reduced,which is not favorable for the long-term preservation of calligraphy and painting works.Hydroxyapatite is the main inorganic component of human bones,and it has high biocompatibility.Recently,the Zhu research group has developed the calcium oleate precursor solvothermal/hydrothermal method,and successfully synthesized ultralong hydroxyapatite nanowires with ultrahigh aspect ratios.The as-prepared ultralong hydroxyapatite nanowires are suitable building materials for new kind of fire-resistant paper.In this thesis,ultralong hydroxyapatite nanowires are added into the commercial unprocessed Xuan paper to prepare the nanocomposite “Xuan paper” with high whiteness,unique ink wetting performance,excellent anti-mildew performance and excellent durability.The properties of the as-prepared nanocomposite “Xuan paper” can be controlled by adjusting the content of ultralong hydroxyapatite nanowires.The as-prepared nanocomposite “Xuan paper” sheets with various weight ratios of ultralong hydroxyapatite nanowires ranging from 10 % to 100% are all superhydrophilic.In contrast,the ink contact angle of the nanocomposite “Xuan paper” can be well controlled by adjusting the weight ratio of ultralong hydroxyapatite nanowires,and the ink contact angle of the nanocomposite “Xuan paper” increases with increasing weight ratio of ultralong hydroxyapatite nanowires.The experimental results show the unique ink wetting behavior of the as-prepared nanocomposite “Xuan paper”,which is absent in the commercial Xuan paper.This new kind of nanocomposite “Xuan paper” is promising for the application in calligraphy and painting arts.The as-prepared nanocomposite “Xuan paper” has superior performance in inhibiting the growth of three kinds of moulds(chaetomium globosum,long branch trichoderma viride,and aspergillus niger)compared with the commercial Xuan paper.During the incubation process,the mildew grows on the surface of the commercial Xuan paper,however,no obvious growth of mildew is observed on the surface of the nanocomposite “Xuan paper”.It is expected that the nanocomposite “Xuan paper” is favorable for long-term safe preservation and is promising for the application in calligraphy and painting arts.