Analyses of Density Phenomena of Glass by a Reaction Model:Density Change of Glass due to Heating (Part 3)

Density changes of glasses in and near their annealing ranges were studied by many investigators. Kanai and Satoh proposed a theory which analyzed change of density with time by introducing the concept of network temperature and the reaction model, but, hereafter, some particular phenomena were observed which could not be explained by their theory and further extension has been needed.In this paper, this extension is done and it is shown that the density phenomena studied by Daragan or Ritland, or particular ones observed by Suetoshi and Hara, Tsurumi, or by the author, can be analyzed rather quantitatively by introducing some energy levels which can be occupied by glass structures, transitions of states between them and changes of transition probabilities with temperature, and by making suitable assumptions for them.It is also speculated that secular changes of ice point or thermal after-effects of glass thermometers can be explained with similar concepts and mathematical treatments.