PMID- 30375879
OWN - NLM
STAT- PubMed-not-MEDLINE
LR  - 20191120
IS  - 1520-5207 (Electronic)
IS  - 1520-5207 (Linking)
VI  - 122
IP  - 46
DP  - 2018 Nov 21
TI  - Composition Dependence of the Glass-Transition Temperature and Molar Volume in 
      Sodium Thiosilicophosphate Glasses: A Structural Interpretation Using a Real 
      Solution Model.
PG  - 10637-10646
LID - 10.1021/acs.jpcb.8b08603 [doi]
AB  - The glass-transition temperature, T(g), and molar volume, V̅, are two physical 
      properties known to exhibit the mixed glass former effect (MGFE), a nonlinear 
      nonadditive increase or decrease from a linear ideal mixing behavior, in ternary 
      glass systems, where the two glass forming species are varied, whereas the glass 
      modifier content remains constant across the system. In the next of our 
      continuing studies of the MGFE in ternary glasses, the T(g) and molar volumes of 
      two ternary glass forming series, 0.5Na(2)S + 0.5[ xSiS(2) + (1 - x)PS(5/2)], the 
      0.50 NSP series, and 0.67Na(2)S + 0.33[ xSiS(2) + (1 - x)PS(5/2)], the 0.67 NSP 
      series, have been determined across the full glass forming range in both series, 
      0 </= x </= 1. The 0.50 NSP glasses were found to have a strongly negative MGFE in 
      the T(g) and a weaker MGFE in the molar volume. The 0.67 NSP series of glasses 
      exhibited weak negative and strong positive MGFEs in the T(g) and molar volumes, 
      respectively. Using the short-range order (SRO) structure model for each glass 
      series that was previously developed, the number of bridging sulfurs (BS) and 
      nonbridging sulfurs (NBS) was determined and analyzed for each of these two 
      series of glasses. A clear linear correlation was observed between the T(g) and 
      both the fraction of BSs, BS/(BS + NBS), and the number of BS per glass former, 
      BS/GF in both series. The molar volumes of both series of glasses were analyzed 
      using both ideal and real solution models of mixing. The molar volumes of the 
      glasses were best fit to the molar volumes of all of the individual molar volumes 
      of the various SRO units. In the ideal solution model, the molar volumes of the 
      SRO units were only fit to molar volumes of the end member glasses, x = 0 and 1. 
      In the real solution model, the molar volumes were best fit to the full 
      composition dependence of the molar volume of all of the glasses. In both cases, 
      the same molar volumes for the SRO units were used to fit both sets of molar 
      volumes of both glass series. It was found that the best-fit molar volumes of 
      both the P and Si SRO units were essentially the same at the same number of 
      NBS/GF. In this study, therefore, it was observed that the MGFE in the T(g) of 
      the glass was linearly correlated with the number of BS per glass former, BS/GF, 
      whereas the MGFE in the molar volumes of the glasses was correlated with the 
      number of NBS per glass former, NBS/GF.
FAU - Watson, Deborah E
AU  - Watson DE
AUID- ORCID: 0000-0002-7300-1413
AD  - Department of Materials Science and Engineering , Iowa State University , Ames , 
      Iowa 50010-2300 , United States.
FAU - Martin, Steve W
AU  - Martin SW
AUID- ORCID: 0000-0002-6472-509X
AD  - Department of Materials Science and Engineering , Iowa State University , Ames , 
      Iowa 50010-2300 , United States.
LA  - eng
PT  - Journal Article
DEP - 20181108
PL  - United States
TA  - J Phys Chem B
JT  - The journal of physical chemistry. B
JID - 101157530
EDAT- 2018/10/31 06:00
MHDA- 2018/10/31 06:01
CRDT- 2018/10/31 06:00
PHST- 2018/10/31 06:00 [pubmed]
PHST- 2018/10/31 06:01 [medline]
PHST- 2018/10/31 06:00 [entrez]
AID - 10.1021/acs.jpcb.8b08603 [doi]
PST - ppublish
SO  - J Phys Chem B. 2018 Nov 21;122(46):10637-10646. doi: 10.1021/acs.jpcb.8b08603. 
      Epub 2018 Nov 8.