03/06/2014. In Glasses, which lack long-range structure completely, this idea works even better!

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1 Composition Structure Property Correlations In Glasses and Glass Ceramics In Glasses, which lack long-range structure completely, this idea works even better! Hellmut Eckert Instituto da Física Sao Carlos Universidade de Sao Paulo Network formers Si, B 3, P 5, Al 3 Network modifiers Li, Na, K Mg, Ca Solid Ion Conductors: For Charge Transport, Defects are essential The more ions, the higher the conductivity, but mobility (structure) is also important (M ) y (Si ) 1-y versus (M ) y (B 3 ) 1-y Li Silicates Na Borates The more defects, the higher the conductivity y 1

2 Distance distributions in states of matter Medium-range order in Glasses B M Network connectivity Interactomic distance correlations Atomic spatial distributions nm Short Range order in Glasses Nano- and microstructure Network former Network modifier B,Si,P Li,Na,K Bonding partners Coordination numbers and -symmetry Bond distances and -angles nm nano-segregation, phase separation, crystallization; ceramization nm

3 Solid State NMR 3 Na Spin Echo Decay B 0 element-selective locally selective quantitative experimentally flexible: E Selective averaging Echo Echo I ( ) M = I0 II d exp ( ) hν ΔE = γ h B Echo M = (µ o /4π) γ 4 h Σr ij -6 H = H Z + H D + H CS + H Q Internucl. distances Coordination numbers and symmetries H = H Z + H D + H CS + H Q homonuclear Distances Dipole Coupling and Atomic distribution Spatial sodium distribution in oxide glasses Prof. Dr. Hellmut Eckert M ~r ij -6 random clustered uniform M [10 6 s - ] M ( 3 Na - 3 Na) vs. number density sodium silicate glasses sodium borate glasses E E E E+08.00E+08.50E+08 N Na [Na/m 3 ] 3

4 The more ions, the higher the conductivity! Random cation distribution in Alkali borate glass (M ) y (Si ) 1-y and (M ) y (B 3 ) 1-y Li Silicates Na Borates y H. Eckert, Z. Phys. Chem. 4, 1591 (010) Cation clustering in Alkali silicate glass Mixed Network Former Effects in xide Glasses non-linear changes in physical properties as a function of composition (M ) 0.33 [(P 5 ) 1-x (B 3 ) x ] 0.67 (M = Li, K, Cs) U. Voigt, H. Eckert, H. Lammert, H. Eckert, Phys. Rev. B 7, (005) T g / K x(b 3 ) M = Li K Cs 4

5 Structural Issues Regarding the Mixed- Network Former Effect Network former species Coordination polyhedra Types of anionic and neutral species present Connectivity distributions Random Linkages? Connectivity Preferences? Clustering/Phase separation? Competition for the network modifier Proportional sharing vs. preferential attraction Relation to physical properties Magic Angle Spinning H aniso = A. {3 cos θ 1} B 0 z Θ 3,4 Θ 1, rotation axis θ = 54.7 H = H Z + H D + H CS + H Q iso nd o. Network former structural units present in the binary systems Phosphorus Boron P P 3 : P 5 P - - P 1 : Pyrophosphate P - P : Metaphosphate - -3 P P 0 : rthophosphate B B B (3) B (4) B NMR spectra of (K ) 0.33 [(P 5 ) 1-x (B 3 ) x ] 0.67 a) B (3) B (4) P (1) P () P (3) δ( 11 Β) / ppm x= 1.0 x= 0.9 x= 0.8 x= 0.7 x= 0.6 x= 0.5 x= 0.4 x= 0.3 x= 0. x= δ( 31 P) / ppm x = 0.9 x = 0.8 x = 0.7 x = 0.6 x = 0.5 x = 0.4 x = 0.3 x = 0. x = 0.1 x = P S. Elbers, W. Strojek, L. Koudelka, H. Eckert, Solid State Nucl. Magn. Reson. 7 (005), 65 5

6 Structural speciation in the (K ) 0.33 [(P 5 ) 1-x (B 3 ) x ] 0.67 system Bioactive glasses and scaffolds Struktureinheiten in % B 4 B 3 B P 3 P P 1 0 0,0 0,1 0, 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1,0 x(b 3 ) 0 < x < 0.5: P () units successively replaced by B (4) units 0.5 < x 1.0: P (3) units successively replaced by B (3) units T g -value and network connectedness (M ) 0.33 [(P 5 ) 1-x (B 3 ) x ] 0.67 (M = Li, K, Cs): 0 < x < 0.5: P () units successively replaced by B (4) units 0.5 < x 1.0: P (3) units successively replaced by B (3) units Effect of Magnesium on the Functional Properties of Bioglasses 4.3Na -6.9(xCa-(1-x)Mg)-46.3Si -.5P 5 T g / K Glass transition temperature number of bridging oxygen per network former unit x(b 3 ) M = Li K Cs [] x(b 3 ) D. Larink, H. Eckert, M. Reichert, S. W. Martin, J. Phys. Chem. C. 16, (01). M = Li K Cs Mg x = 1.0 x = 0.5 x = 0.0 Mg increases thermal stability No influence on dissolution kinetics 6

7 IR Reflectance differentiates between ACP and HCA Phase quantification possible by 31 P NMR ACP HCA ACP HCA M.T. Souza, M. C. Crovace, C. Schröder, H. Eckert,. Peitl, E. D. Zanotto, J.Non-Cryst.Solids 38, 57 (013) Effect of Mg Content on Mineralization Rates NMR periodic system for solids 1 H 3 He 7 Li Be 3 Na 5 Mg 11 B 13 C 15 N F Ne 7 Al 9 Si 31 P 33 S 35 Cl Ar 43 Ca 45 Sc 47 Ti 39 K 51 V 53 Cr 55 Mn 57 Fe 59 Co 61 Ni 65 Cu 67 Zn 71 Ga 73 Ge 75 As 77 Se 79 Br Kr 87 Rb Sr 89 Y 93 Nb 95 Mo Tc Ru 103 Rh 105 Pd 107 Ag 113 Cd 115 In 117 Sn 13 Sb 15 Te 17 I 19 Xe 91 Zr 133 Cs Hf Ta 183 W Re s Ir 195 Pt Au 01 Ba La Hg 05 Tl 07 Pb Bi Po At Rn Mg has no effect on rate of ACP formation but delays the crystallization of HCA Fr Ra Ac Good candidates for solid state NMR Suitable candidates, but poor sensitivity Unsuitable elements 7

8 Acknowledgments Jan-Dirk Epping Ulrike Voigt Stefan Elbers Wenzel Strojek Dominika Zielniok Dirk Larink Deutsche Forschungsgemeinschaft, SFB 458 FAPESP-CEPID 013/ Glasses and Glass-ceramics Entropy. Temp. T g T melt Glass ceramics 195: Invention of glass ceramics by accident Dr. Donald Stookey (Corning) Functional materials produced by the controlled crystallization of glasses nucleation growth consolidation Magnetite in soda-lime glass 8

9 Production steps Glass-ceramics Temperature melting shaping T L growth Tg nucleation GC Time Crystallization of Dental Ceramics Quantified by Advanced NMR Lithium Disilicate Dental Ceramics 7 Li-> 9 Si CP NMR XRD Rietveld 650 C Li-Disilicate Li-Metasilicate 900 C Li Disilicate Glass Glass Ceramic Glass Ceramic 500 C 10 Stunden 500 C 90 Stunden 500 C 75 Stunden Intensität / counts p. second Experiment Anpassung des Profils Anpassung des Hintergrundes 40-50% cryst. Soft material CAD-CAM 80-90% cryst. very hard 500 C 50 Stunden δ / ppm θ / o 9

10 Monitoring phase evolution by 9 Si solid state NMR Distance Correlations Network former - Modifier Spatial Cation Distribution Li Si 3 Li Si 5 Residual glass Si, B, P Li, Na Sol-Gel Glasses Si(C H 5 ) H Si(H) C H 5 H n Si(H) 4 Si + n H Probing Cation Clustering by Double Resonance NMR 7 Li-irradiation: Q (3) signal weakened Q (3) Q (4) Q (4) - Signal unchanged Bio-active glasses: Na/Ca/Si/P/ osteoconduction osteoproduction osteoinduction chemische Verschiebung [ppm] 10

11 Cation Clustering in Li-Silicate Glasses Spin Echo...also implies clustering of the non-bridging atoms and strong nbo Cation interactions z y y Si - Li + Li + - Si Si - Li + Si y y x y x t D dephasing x Si Li Li + Si Si x t D x 180 y (or x) Li + - Si Si refocusing Q (3) Li WW: stark Q (4) Li WW: schwach B B B B Equipment 3 Na Spin Echo Decay Spectroscopy Magnet Probe Sample in Rotor Console /Computer Echo Echo I ( ) M = I0 II d exp ( ) Echo II µ 0 4 M d = F( I) γ h 4π j 3 1 3cosθ 3 rij 11

12 Glass a disordered solid Glasses and Glass-ceramics Entropy. Temp. T g T melt Glass ceramics 195: Invention of glass ceramics by accident Dr. Donald Stookey (Corning) Functional materials produced by the controlled crystallization of glasses nucleation growth consolidation Magnetite in soda-lime glass 1

13 Production steps Temperature melting shaping T L growth Tg nucleation Time GC 13