ガラス状ホウケイ酸ソーダの粘性

概要

論文の詳細を見る
Viscosity of sodium borosilicate glasses has been measured by a newly designed parallel plate viscometer in a range of viscosity from 10^<10> to 10^6 poise in order to compare the network forming ability of B_2O_3 with that of SiO_2 in silicate glasses. The measurements are carried out mainly on the two series of samples, namely, Na_2O・SiO_2-B_2O_3 (10-50mole%) and Na_2O・2SiO_2-B_2O_3 (0-50mole%) systems. Obtained results are summarized as follows : 1) Addition of B_2O_3 into silicate glasses brings about an increase of the viscosity. But the increasing rate of viscosity becomes lower at higher content of B_2O_3 in the glass. 2) Activation energy of viscous flow is increased markedly by an addition of 10 mole% of B_2O_3 into silicate glasses. However, it almost remains constant by the further addition of B_2O_3. 3) Addition of larger amount of B_2O_3 causes a decrease of viscosity due to a formation of oxygen three coordinated boron atoms. This situation can be found in the case of Na_2O・2SiO_2-50mole%B_2O_3 sample. 4) The effect of an addition of B_2O_3 on the viscosity increase is nearly the same as that of SiO_2 on the equimolar basis in dilute range of B_2O_3 content.viscosityviscometerglassy statesodium borosilicateborate anomaly
東北大学の論文
1986-09-30