Rewritable phosphorescent paper by the control of competing kinetic and thermodynamic self-assembling events

Nat Mater. 2005 Jul;4(7):546-9. doi: 10.1038/nmat1401. Epub 2005 Jun 19.

Abstract

Security inks have become of increasing importance. They are composed of invisible substances that provide printed images that are not able to be photocopied, and are readable only under special environments. Here we report a novel photoluminescent ink for rewritable media that dichroically emits phosphorescence due to a structural bistability of the self-assembled luminophor. Long-lasting images have been developed by using conventional thermal printers, which are readable only on exposure to ultraviolet light, and more importantly, are thermally erasable for rewriting. Although thermally rewritable printing media have already been developed using visible dyes and cholesteric liquid crystals, security inks that allow rewriting of invisible printed images are unprecedented. We realized this unique feature by the control of kinetic and thermodynamic processes that compete with one another in the self-assembly of the luminophor. This strategy can provide an important step towards the next-generation security technology for information handling.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Crystallization / methods*
  • Information Storage and Retrieval / methods*
  • Ink*
  • Kinetics
  • Luminescent Agents / analysis
  • Luminescent Agents / chemistry*
  • Luminescent Agents / radiation effects*
  • Luminescent Measurements
  • Materials Testing
  • Paper*
  • Printing / methods*
  • Product Labeling / methods*
  • Security Measures
  • Thermodynamics
  • Ultraviolet Rays

Substances

  • Luminescent Agents