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Sodium Transport in the Na 2 O‐H 2 O‐SiO 2 Glass System
Author(s) -
MOLINELLI JOYCE,
TOMOZAWA MINORU,
TAKATA MASASUKE
Publication year - 1985
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.1985.tb09658.x
Subject(s) - conductivity , analytical chemistry (journal) , alkali metal , diffusion , electrical resistivity and conductivity , sodium , chemistry , ternary numeral system , mineralogy , materials science , thermodynamics , chromatography , physics , organic chemistry , phase (matter) , electrical engineering , engineering
The variation with water content of dc conductivity and Na diffusion coefficient for the Na 2 O · 4siO 2 and Na 2 O · 2SiO 2 glass systems was found to be similar to that of the Na 2 O.3SiO 2 series reported earlier. The conductivity was estimated for the ternary system Na 2 O‐H 2 O‐SiO 2 by combining the present results with the previous data on the Na 2 O · 3SiO 2 system. When the conductivity of those glasses with a constant [Na 2 O] + [H 2 O] content was plotted against water content, a pronounced mixed “alkali” effect was demonstrated. The Haven ratio, calculated by comparison of the dc conductivity to the Na diffusion coefficient at 100°C for each of the three glass systems, was found to increase toward unity with increasing water content. This suggests that the addition of water reduces the number of sodium charge carriers. The subsequent increase in conductivity beyond the minimum with the introduction of larger amounts of water is, probably, due to an increase in the mobility of the Na + ions.