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DIANE HOLLAND, GLASS GROUP, DEPARTMENT OF PHYSICS, UNIVERSITY OF WARWICK. Cation Induced Changes to the Structure and Behaviour of BNFL Wasteform Glass. Diane Holland Department of Physics, University of Warwick, Coventry CV4 7AL.
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DIANE HOLLAND, GLASS GROUP, DEPARTMENT OF PHYSICS, UNIVERSITY OF WARWICK Cation Induced Changes to the Structure and Behaviour of BNFL Wasteform Glass. Diane Holland Department of Physics, University of Warwick, Coventry CV4 7AL ACTINET: Cambridge September 2005
DIANE HOLLAND, GLASS GROUP, DEPARTMENT OF PHYSICS, UNIVERSITY OF WARWICK Funding Charlie Scales - BNFL Students Kathryn Luk Jonathan Roderick Adam Duddridge Moinul Islam Ben Parkinson ACTINET: Cambridge September 2005
DIANE HOLLAND, GLASS GROUP, DEPARTMENT OF PHYSICS, UNIVERSITY OF WARWICK These oxides would have different rôles in glass. ACTINET: Cambridge September 2005
DIANE HOLLAND, GLASS GROUP, DEPARTMENT OF PHYSICS, UNIVERSITY OF WARWICK Added oxide ACTINET: Cambridge September 2005
DIANE HOLLAND, GLASS GROUP, DEPARTMENT OF PHYSICS, UNIVERSITY OF WARWICK WASTEFORM GLASS COMPOSITION (mol%) (MW) • mixed alkali glass • close to N4 maximum • K = 3.26 R = 1.1 • typical waste loading ~ 20 wt% ACTINET: Cambridge September 2005
DIANE HOLLAND, GLASS GROUP, DEPARTMENT OF PHYSICS, UNIVERSITY OF WARWICK Glasses studied: x M2On (100-x) MW (x in mol%) K constant R changes depending on x and on oxide ACTINET: Cambridge September 2005
DIANE HOLLAND, GLASS GROUP, DEPARTMENT OF PHYSICS, UNIVERSITY OF WARWICK Water solubility Soxhlet; 25mm dia x 1mm thick disc polished both sides; 14 days; ~75oC; 300ml distilled water. ACTINET: Cambridge September 2005
DIANE HOLLAND, GLASS GROUP, DEPARTMENT OF PHYSICS, UNIVERSITY OF WARWICK Glass Transition ACTINET: Cambridge September 2005
DIANE HOLLAND, GLASS GROUP, DEPARTMENT OF PHYSICS, UNIVERSITY OF WARWICK Glass Transition ACTINET: Cambridge September 2005
DIANE HOLLAND, GLASS GROUP, DEPARTMENT OF PHYSICS, UNIVERSITY OF WARWICK • Species distribution • Partition of modifier between borate and silicate • [SiO4] [BO3] [SiO4]- [BO4]- [BO3]- • Effect of added oxide on this partition • Does it behave like additional modifier? • Does it introduce extra network polyhedra which compete for the modifier? Particularly important if electroneutrality involved e.g. [AlO4]- • Does it change the interaction of the borate and silicate units? • Does it change the equilibrium of the partition? ACTINET: Cambridge September 2005
DIANE HOLLAND, GLASS GROUP, DEPARTMENT OF PHYSICS, UNIVERSITY OF WARWICK DELL & BRAY MODEL Borate units B4 = [BO4] = f2 B3 = [BO3] = f1+f3+f4+f5 ACTINET: Cambridge September 2005
DIANE HOLLAND, GLASS GROUP, DEPARTMENT OF PHYSICS, UNIVERSITY OF WARWICK DELL & BRAY MODEL K = 3.26 Region 3: Rmax< R < RD1 Extra M2O goes to form Q3. B: B3, B4(Si) N4=Rmax Si: Q4(B), Q3 Region 2: 0.5 < R < Rmax Extra [BO4]- combine with [SiO4] to give reedmergnerite units B: B3(B), B4(B), B4(Si) N4=R Si: Q4(Si) and Q4(B) Region 3: RD1 < R < RD2 [BO4]- go to [BO3]- Region 1: R < 0.5 All M2O goes to form [BO4]-. No mixing of borate and silicate. B: B3(B), B4(B) N4=R Si: all Q4(Si) ACTINET: Cambridge September 2005
DIANE HOLLAND, GLASS GROUP, DEPARTMENT OF PHYSICS, UNIVERSITY OF WARWICK Modifications to Dell model. • Wu et al (1986) & Zhong et al (1988) & Martin et al (1993) • Above a certain R, dependent on K, M+ shared proportionally between the two networks • Bunker et al (1990), Wang et al (1998) • much better mixing of B3 and Si networks • Stebbins (2003) • B4 strongly associated with Si • B3(ring) strongly associated with B3(ring) • B3(non-ring) randomly distributed ACTINET: Cambridge September 2005
DIANE HOLLAND, GLASS GROUP, DEPARTMENT OF PHYSICS, UNIVERSITY OF WARWICK What can we measure – 11B NMR? B4 B3 ACTINET: Cambridge September 2005
DIANE HOLLAND, GLASS GROUP, DEPARTMENT OF PHYSICS, UNIVERSITY OF WARWICK R M2O-B2O3-K SiO2 (M = Na + Li) ACTINET: Cambridge September 2005
DIANE HOLLAND, GLASS GROUP, DEPARTMENT OF PHYSICS, UNIVERSITY OF WARWICK • Can get good fit of B4. • can get good estimate of N4 • Difficult to get unambiguous fit of B3 peak to individual components. • NB – there must be more than 2 components + complication of different next nearest neighbours B4= f2 B3= f1+ f3+f4… ACTINET: Cambridge September 2005
DIANE HOLLAND, GLASS GROUP, DEPARTMENT OF PHYSICS, UNIVERSITY OF WARWICK K = 3.26 ACTINET: Cambridge September 2005
DIANE HOLLAND, GLASS GROUP, DEPARTMENT OF PHYSICS, UNIVERSITY OF WARWICK K = 3.26 ACTINET: Cambridge September 2005
DIANE HOLLAND, GLASS GROUP, DEPARTMENT OF PHYSICS, UNIVERSITY OF WARWICK Region 1: R < 0.5 All M2O goes to form [BO4]-. But there is mixing of borate and silicate. B: B3(B), B4(B), B4(Si) N4=R Si: Q4(Si), Q4(B) K = 3.26 ACTINET: Cambridge September 2005
DIANE HOLLAND, GLASS GROUP, DEPARTMENT OF PHYSICS, UNIVERSITY OF WARWICK Region 2 and 3: 0.5 < R < Rd1 More M2O goes to form NBO on Si than predicted. B: B3(B), B4(B), B4(Si) N4< R Si: Q4(Si), Q4(B), Q3 Region 1: R < 0.5 All M2O goes to form [BO4]-. But there is mixing of borate and silicate. B: B3(B), B4(B), B4(Si) N4=R Si: Q4(Si), Q4(B) K = 3.26 ACTINET: Cambridge September 2005
DIANE HOLLAND, GLASS GROUP, DEPARTMENT OF PHYSICS, UNIVERSITY OF WARWICK Region 3: RD1 < R < RD2 [BO4]- more stable than predicted Region 2 and 3: 0.5 < R < Rd1 More M2O goes to form NBO on Si than predicted. B: B3(B), B4(B), B4(Si) N4< R Si: Q4(Si), Q4(B), Q3 Region 1: R < 0.5 All M2O goes to form [BO4]-. But there is mixing of borate and silicate. B: B3(B), B4(B), B4(Si) N4=R Si: Q4(Si), Q4(B) K = 3.26 ACTINET: Cambridge September 2005
DIANE HOLLAND, GLASS GROUP, DEPARTMENT OF PHYSICS, UNIVERSITY OF WARWICK K = 3.26 ACTINET: Cambridge September 2005
DIANE HOLLAND, GLASS GROUP, DEPARTMENT OF PHYSICS, UNIVERSITY OF WARWICK K = 3.26 ACTINET: Cambridge September 2005
DIANE HOLLAND, GLASS GROUP, DEPARTMENT OF PHYSICS, UNIVERSITY OF WARWICK Change in N4 means what? K = 3.26 ACTINET: Cambridge September 2005
DIANE HOLLAND, GLASS GROUP, DEPARTMENT OF PHYSICS, UNIVERSITY OF WARWICK Intermediates e.g. Al2O3 + M2O 2 M+[AlO4/2]- modifiers Decrease in N4 means what? K = 3.26 ACTINET: Cambridge September 2005
DIANE HOLLAND, GLASS GROUP, DEPARTMENT OF PHYSICS, UNIVERSITY OF WARWICK N4 data ACTINET: Cambridge September 2005
DIANE HOLLAND, GLASS GROUP, DEPARTMENT OF PHYSICS, UNIVERSITY OF WARWICK +1 cations - modifiers R = ([Li2O] + [Na2O] + [Cs2O])/[B2O3] ACTINET: Cambridge September 2005
DIANE HOLLAND, GLASS GROUP, DEPARTMENT OF PHYSICS, UNIVERSITY OF WARWICK +2 cations – modifiers CaO, SrO, BaO R = ([Li2O] + [Na2O] + [MO])/[B2O3] ACTINET: Cambridge September 2005
DIANE HOLLAND, GLASS GROUP, DEPARTMENT OF PHYSICS, UNIVERSITY OF WARWICK 27Al spectra ACTINET: Cambridge September 2005
DIANE HOLLAND, GLASS GROUP, DEPARTMENT OF PHYSICS, UNIVERSITY OF WARWICK +3 cations – conditional network former Al2O3 Greater reduction in N4 than expected. Some modifier goes to Si network. NB – the 27Al shift is consistent with [Al(OSi)4] (55-70ppm) rather than[Al(OB)4] (40-45ppm) Al2O3 + M2O 2 M+[AlO4]- R = ([Li2O] + [Na2O] - [Al2O3])/[B2O3] ACTINET: Cambridge September 2005
DIANE HOLLAND, GLASS GROUP, DEPARTMENT OF PHYSICS, UNIVERSITY OF WARWICK +2 cations – ZnO, PbO - modifiers? R = ([Li2O] + [Na2O] + [MO])/[B2O3] ACTINET: Cambridge September 2005
DIANE HOLLAND, GLASS GROUP, DEPARTMENT OF PHYSICS, UNIVERSITY OF WARWICK Water solubility ACTINET: Cambridge September 2005
DIANE HOLLAND, GLASS GROUP, DEPARTMENT OF PHYSICS, UNIVERSITY OF WARWICK +2 cations – ZnO, PbO - intermediates? R = ([Li2O] + [Na2O] – 0.5[MO])/[B2O3] assumes [MOn]- e.g. [PbO3]- ACTINET: Cambridge September 2005
DIANE HOLLAND, GLASS GROUP, DEPARTMENT OF PHYSICS, UNIVERSITY OF WARWICK +2 cations – intermediates ZnO, PbO? R = ([Li2O] + [Na2O] – [MO])/[B2O3] assumes [MOn]2- e.g. [PbO4]2- ACTINET: Cambridge September 2005
DIANE HOLLAND, GLASS GROUP, DEPARTMENT OF PHYSICS, UNIVERSITY OF WARWICK +3 cations – modifiers Bi2O3, La2O3, Al2O3? R = ([Li2O] + [Na2O] + 3[M2O3])/[B2O3] ACTINET: Cambridge September 2005
DIANE HOLLAND, GLASS GROUP, DEPARTMENT OF PHYSICS, UNIVERSITY OF WARWICK +3 cations – intermediates Bi2O3, La2O3, Al2O3? Al2O3 + M2O 2 M+[AlO4]- R = ([Li2O] + [Na2O] - [Al2O3])/[B2O3] ACTINET: Cambridge September 2005
DIANE HOLLAND, GLASS GROUP, DEPARTMENT OF PHYSICS, UNIVERSITY OF WARWICK BUT Binary borates x M2/zO (1-x) B2O3 ACTINET: Cambridge September 2005
DIANE HOLLAND, GLASS GROUP, DEPARTMENT OF PHYSICS, UNIVERSITY OF WARWICK ALSO Ignoring what is happening near Si ACTINET: Cambridge September 2005
DIANE HOLLAND, GLASS GROUP, DEPARTMENT OF PHYSICS, UNIVERSITY OF WARWICK 29Si spectra for +3 additions ACTINET: Cambridge September 2005
DIANE HOLLAND, GLASS GROUP, DEPARTMENT OF PHYSICS, UNIVERSITY OF WARWICK ACTINET: Cambridge September 2005
DIANE HOLLAND, GLASS GROUP, DEPARTMENT OF PHYSICS, UNIVERSITY OF WARWICK ACTINET: Cambridge September 2005
DIANE HOLLAND, GLASS GROUP, DEPARTMENT OF PHYSICS, UNIVERSITY OF WARWICK Corrosion: ACTINET: Cambridge September 2005
DIANE HOLLAND, GLASS GROUP, DEPARTMENT OF PHYSICS, UNIVERSITY OF WARWICK VOLATILISATION: problem with 137Cs loss from melt xCs2O.(1-x)MW glasses – mass loss after 30 mins at 1000oC. ACTINET: Cambridge September 2005
DIANE HOLLAND, GLASS GROUP, DEPARTMENT OF PHYSICS, UNIVERSITY OF WARWICK NB: boropollucite CsBSi2O6 (≡ K = 4; R = 1) and N4 = 1. boropollucite loses mass at ~ 1030oC 3CsBSi2O6 2CsBSi3O8 + “CsBO2”↗ Not quite this simple in glass – Na and Si also detected in deposit Reedmergnerite units detected with Raman. ACTINET: Cambridge September 2005
DIANE HOLLAND, GLASS GROUP, DEPARTMENT OF PHYSICS, UNIVERSITY OF WARWICK • NEXT STEPS: • 17O MQMAS NMR – try to establish the various M-O-X combinations • high T NMR – study changes relevant to volatilisation • Mo, Ru, Tc NMR – formation of molybdates, ruthenates and pertechnetates ACTINET: Cambridge September 2005
DIANE HOLLAND, GLASS GROUP, DEPARTMENT OF PHYSICS, UNIVERSITY OF WARWICK THANK-YOU ACTINET: Cambridge September 2005