@article{25036,
  keywords = {aerogel, air pressure, oxygen concentration, oxygen molecules, photoluminescence},
  author = {Michael R Ayers and Arlon J Hunt},
  title = {Molecular oxygen sensors based on photoluminescent silica aerogels},
  abstract = {<p>Photoluminescent silica aerogel acts as the active element of an optical sensor for molecular oxygen. The luminescent aerogel is prepared by the action of energized reducing gases on a standard silica aerogel. Intensity of aerogel photoluminescence decreases as the collision frequency between oxygen molecules and the luminescent carriers in the aerogel matrix increases. This behavior is a characteristic of many photoluminescent materials and arises from a transfer of energy from the aerogel to surrounding oxygen molecules. A sensor for oxygen concentration or air pressure can therefore be simply constructed utilizing an ultraviolet source for excitation and a suitable detector for the emitted visible signal. Stern-Volmer quenching constants for the aerogel sensing element are 1.55×10<sup>-2</sup> Torr<sup>-1</sup> for hydrophilic aerogel and 2.4×10<sup>-3</sup> Torr<sup>-1</sup> for hydrophobic aerogel.</p>},
  year = {1998},
  journal = {Journal of Non-Crystalline Solids},
  volume = {225},
  pages = {343-347},
  month = {04/1998},
  doi = {10.1016/S0022-3093(98)00051-9},
  language = {eng},
}