The paper has been developed at the Shanghai Institute of Ceramics of Chinese Academy of Sciences. The method used to create the paper is described as a “one-step solvothermal method.” The process leads to the creation of an antibacterial silver nanoparticle-decorated hydroxyapatite nanowire paper. The presence of silver renders the paper antibacterial; the nano-material renders the paper fire-resistant (as well as allowing it to be used at high temperatures) and helping to make the material highly flexible.
The paper is created from ultra-long hydroxyapatite nanowires, which serve as the raw material. The nanowires are formed from the solvothermal method, and the use of an alcohol based extraction process where the material is extracted from soluble phosphates. Here calcium oleate is used as the calcium source and precursor, and different kinds of phosphate sodium salts are used as the phosphorus sources in mixed solvent of ethanol and water. High heat also plays a role in the material formation.
Ultralong hydroxyapatite nanowires have diameters of tens of nanometers and lengths from several hundred micrometers up to nearly one millimeter.
In trials the paper was also revealed to have a high mechanical strength. The paper can be produced up to a size of A4 (the international code for paper of a size 21 centimeters by 29.7 centimeters). Images can be directly printed to a color printer.
The key points are the antibacterial properties, which make the paper useful for hospitals and other biomedical applications; and fire-resistance, which will appeal to those who wish to protect valuable documents, according to the lead researcher, Professor Zhu Yingjie.
As well as paper, the technique can be used with bone tissue engineering, drug delivery, adsorbent for organic pollutants and heavy metal ions.
The research has been published in the journal Chemistry-A European. The research article is titled “One-Step Synthesis of Silver Nanoparticle-Decorated Hydroxyapatite Nanowires for the Construction of Highly Flexible Free-Standing Paper with High Antibacterial Activity.”
