Sodium borate glasses

Qiu J. R., Kondo Y., Minra K., Mitsuyu T. and Hirao K., Infrared femtosecond laser induced visible long lasting phosphorescence in Mn " doped sodium borate glasses, Jpn. J. Appl. Phys. 38 (1999) pp. L649-L651. 

Fig. 18 B Na REDOR results for sodium borate glasses recorded with the pulse sequence of Fig. 8a. The 180° solid pulse length on Na was 8 ps and the rotor speed was 12 kHz. (a, top) site resolved REDOR data on trigonal and tetrahedral boron species, (b, bottom) site-...

B Na REDOR NMR has been used to probe the spatial relationship between the network former (boron) and the network modifier (sodium) species in sodium borate glasses. Under conditions of fast MAS, site resolved REDOR data have been obtained, revealing that the trigonal and tetrahedral units interact more or less equally strongly with the sodium ions. 

Another, exploratory version of the Na-S system (aimed at present at stationary applications) is under development at Dow Chemical Company. It operates at 300°C and utilizes hollow sodium borate glass fibers as electrolyte in the form of thousands of thin hollow fibers sealed at one end and open at the other to a common reservoir of molten sodium. The fibers are wrapped in Mo-coated aluminum foil which serves as a positive electrode for the polysulfide melt, which fills the space between the fiber wall and the Al. 

Use the data given below to calculate the Abbe number and the molar refractivity of the following sodium borate glasses. Plot the Abbe number, n, and the molar refractivity versus soda content. Offer an explanation for the behavior of each curve. 

As noted in Sec. 6.1.3.1, pure BjOj glass is very hygroscopic, even soluble in water. The same is true for many binary alkali and alkaline earth borate glasses. The solubihty of sodium borate glasses has been utilized to prevent rot in telephone poles and fence poles. 

Some recent additional evidence for a dipole-dipole transfer between Sm(III) and Nd(III) (Joshi, 1978a), and Eu(III) and Nd(III) in sodium borate glass (Joshi, 1978b) was found. In addition, energy transfer from Tb(III) to Sm(III) in barium borate glass as been found to take place by a dipole-dipole mechanism (Agarwal et al., 1984). 

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