Dene Taylor - Color-changing emulsions for freeze indicators

Version 1

      Publication Details (including relevant citation   information):

     

      United States   Patent 8,430,053;April 30, 2013

      Abstract:

     

     

      Color-changing   emulsions for freeze indicators

      Taylor;   Dene H. Lentz; Carl M. & Smith; Dawn E

      Abstract

     

      A color-changing emulsion for use in a freeze indicator can employ a dispersion medium, for example, an aqueous liquid, a first reactant phase and a second reactant phase, which two reactant phases can both be dispersed in the dispersion medium. The first reactant phase includes a hydrophobic liquid and a first reactant, for example, a color precursor such as a leuco dye. The second reactant phase can include a hydrophobic liquid, and includes, or can be, a second reactant, for example, a color developer such as a leuco dye developer. The first and second reactant phases can be essentially unmixed, and can be co-reactable to provide a color change. In response to a freezing temperature, the color-changing emulsion can coagulate and change color irreversibly. An intense color change can be obtained by using, for example, a suitable leuco dye precursor and developer.

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