Paper and paper products are indispensable in the daily life, while human health is threatened by the bacteria attaching on the paper and spreading through the crowds. Due to its highly efficient antibiosis, the antibacterial fire-resistant inorganic paper thus possesses a good application prospect. It also has research significance and practical value in preventing the mildew from the collections of the books and the cultural relics.

The research team led by Prof. ZHU Yingjie from Shanghai Institute of Ceramics of Chinese Academy of Sciences discovered a one-step solvothermal method for the preparation of a new kind of highly flexible antibacterial silver nanoparticle-decorated hydroxyapatite nanowire paper. The size and the thickness of the antibacterial inorganic paper are controllable. The as-prepared antibacterial inorganic paper features high flexibility, good biocompatibility and high antibacterial properties, nonflammability and resistance to high temperature. The study was published in Chemistry-A European Journal and was selected as the front cover art article and the hot paper.

The exploration of the preparation methods for ultralong hydroxyapatite nanowires played a vital role in manufacturing the raw material of the fire-resistant inorganic paper. The team developed a calcium oleate precursor solvothermal method for the preparation of ultralong hydroxyapatite nanowire by using a variety of alcohols. Its length reaches more than 100 microns, with the maximum even close to 1000 microns. This method can be applied to a variety of different soluble phosphates, which are used as the phosphorus source for the preparation of ultralong hydroxyapatite nanowires. In addition, the good repeatability of ultralong hydroxyapatite nanowires was demonstrated through the large-scale preparation technology (10-liter volume autoclave). Preparation technology of ultralong hydroxyapatite nanowires with low cost is being explored by the team.

Through a large amount of experiment, the team explored and optimized formulations of ultralong hydroxyapatite nanowire suspension, inorganic adhesives, and the fire-resistant paper making technology, which greatly improved the mechanical strengths and other properties of the as-prepared fire-resistant inorganic paper. The sheets of fire-resistant inorganic paper with A4 size (21 cm x 29.7cm) have been successfully developed, which can be directly printed with high-quality in the colour printer. The main performance indexes of the as-prepared fire-resistant inorganic paper accord with the national standards for copying paper and can be used as the office paper, calligraphy paper, etc.

The research team is now focusing on exploring various applications of the fire-resistant inorganic paper, such as special fire-resistant inorganic paper, functionalized fire-resistant paper, fire-resistant inorganic paper for adsorption and filtering, fire-resistant materials, and biomedical materials. On July 17, 2016, Chemistry Views reported this new kind of fire-resistant antibacterial inorganic paper. On August 1, 2016, Chemical Engineering highlighted this research work.

In 2014, ZHU's team successfully prepared a new kind of fire-resistant inorganic paper made from ultralong hydroxyapatite nanowires featuring high flexibility, high biocompatibility, and high thermal stability. Its promising application in various fields received extensive interests. Since then, the team has made a series of scientific breakthroughs in the fire-resistant inorganic paper.

The study is supported by the Science and Technology Commission of Shanghai Municipality, Shanghai Institute of Ceramics of Chinese Academy of Sciences, etc.