Anhydrous Silicophosphoric Acid Glass: Thermal Properties and Proton Conductivity.
Chemphyschem
; 23(3): e202100840, 2022 02 04.
Article
em En
| MEDLINE
| ID: mdl-34862847
ABSTRACT
Anhydrous silicophosphoric acid glass with an approximate composition of H5 Si2 P9 O29 was synthesized and its thermal and proton-conducting properties were characterized. Despite exhibiting a glass transition at 192 °C, the supercooled liquid could be handled as a solid up to 280 °C owing to its high viscosity. The glass and its melt exhibited proton conduction with a proton transport number of â¼1. Although covalent O-H bonds were weakened by relatively strong hydrogen bonding, the proton conductivity (4×10-4 â
S cm-1 at 276 °C) was considerably lower than that of phosphoric acid. The high viscosity of the melt was due to the tight cross-linking of phosphate ion chains by six-fold-coordinated Si atoms. The low proton conductivity was attributed to the trapping of positively charged proton carriers around anionic SiO6 units (expressed as (SiO6/2 )2- ) to compensate for the negative charges.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Prótons
/
Vidro
Idioma:
En
Revista:
Chemphyschem
Ano de publicação:
2022
Tipo de documento:
Article