One of the perennial problems humanity has faced ever since the first scribe put "pen" to paper is preservation of documents. Of course, that issue has been amplified to the multi-terabyte level today, but there remains an urge to ensure that important documents do not crumble and fade and will still be legible for translations by future generations.
From papyrus to acid-free recycled paper, we've been ringing in the sheaves, and although there was a time when futurologists and tech pundits touted the so-called "paperless office" that seems such a fanciful notion even in the age of smart phones and tablet computers. Now, materials scientist Ying-Jie Zhu, of the Shanghai Institute of Ceramics, Chinese Academy of Sciences, is boning up on hydroxyapatite so that he and his team might produce a highly flexible and nonflammable inorganic alternative to cellulose-based paper. Critically, paper pulp contains a high proportion of lignin, from wood, which yellows in the air under light, cellulose also generates formic, acetic, lactic, and oxalic acids all of which can degrade paper documents. But, it is of course, their rotting and burning that have been the cause of significant written artifact loss of the centuries.
Hydroxyapatite is a naturally occurring mineral - essentially calcium phosphate with associated hydroxyl groups. It is present in mineral deposits but is familiar to scientists investigating biomimetic materials in a modified form as "bone mineral" making up as it does half the mass of bone. It is also present in various forms in dental enamel and in calcifications - natural body structures as well as deposits present in disease or tissue damage.
The team has turned to ultra-long nanowires of hydroxyapatite synthesized from a calcium oleate precursor in which hydrophilicity/hydrophobicity can be fine tuned during the process and sheets of paper made using the traditional technique employed to convert wood pulp to paper. "We reckon this new type of fireproof paper could be used for important written or printed documents that could be a permanent and safe storage medium for information," Zhu told me. Moreover, as with many inventions the same material could have a second use as a recyclable material for the adsorption of organic pollutants from waste water.
There are countless documents that humanity might wish to preserve in printed form, I heard not too many weeks ago that there was a plan to print out the corpus of updates from the most famous of 140-character microblogging sites. I'm not sure anyone would have quite the apatite for that though…
References
Lu, B.-Q., Zhu, Y.-J. and Chen, F. (2014), Highly Flexible and Nonflammable Inorganic Hydroxyapatite Paper. Chem. Eur. J; http://dx.doi.org/10.1002/chem.201304439
David Bradley blogs at http://www.sciencebase.com and tweets @sciencebase, he is author of the popular science book "Deceived Wisdom".