In situ Experiments in Material Science:

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Junior Little
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1 In situ Experiments in Material Science: Rheo-Saxs, Rheo-Dielectric, Rheo-NMR, In situ-nmr Prof. Dr. M. Wilhelm Institute of Chemical and Polymer Chemistry

Fourier Transform-Rheology (FT-Rheology) Linear Region: Nonlinear Region: SAOS (Small Amplitude Oscillatory Shear) Phase angle 0 < d < 90 Normalized Stress (Pa) LAOS (Large Amplitude Oscillatory

2 Fourier Transform-Rheology (FT-Rheology) Linear Region: Nonlinear Region: SAOS (Small Amplitude Oscillatory Shear) Phase angle 0 < d < 90 Normalized Stress (Pa) LAOS (Large Amplitude Oscillatory Shear) 10 0 strain 1000% FT time (s) In/I1 strain 1000% Frq. (rad/s) σ(t) I sin( ωt+ δ) σ (t) I sin( ωtt + φ) ) + II sin(3 ωtω+ tφ+ ) φ+ ) I+ sin(5 I sin(5 ωt+ ωφt+ ) +L φ ) +L Log G'and G"? 0 (%)

3 Rheo-SAXS : Schematic view (1) Detector Lower plate MARS X-ray Beam Upper plate

4 Rheo-SAXS : Real setup (2) 2D Detector Upper plate X-ray Pin - Hole The mirror arm Top view Lower pate transmotor & ducer X-ray beam path

5 Rheo-SAXS of Liquid crystal (8CB) : 4-cyano-4?-octylbiphenyl Crystalline Smectic A Nematic Isotropic Rheological property at each stage SAXS results at each stage G', G" [Pa] Relaxation 40min Relaxation 40min 10 2 LAOS 1 LAOS 2 LAOS A B C D Time [min] Experimental condition Frequency 10 Hz Strain amplitude 100% Gap: 1.32 mm, Diameter: 60 mm A C B D

6 Periodic Oscillation during LAOS of cylindrical PS-b-PI LAOS: 0.02 Hz; 100%; 140 C Phase 1 Phase 2 Phase 3 Phase 4 Phase 5 Phase 1 90? t = 0 5s 15s 25s 35s 45s 55s = Deformation at time t 5405 s 5415 s 5425 s 5435 s 5435 s 5455 s

7 Dielectric Spectroscopy Experimenal Setup Oven Transducer Rheometer Dielectric-Analyzer Motor (Oscillatory motion)

8 Dielectric Spectroscopy of Neat Polymers (Stockmeyer Classification ) µ i H 3 C µ Sum type A, e.g. 1,4-cis-PI C CH 2 CH H 2 C n µ i H Cl type B, e.g. PVC C C H H n CH 3 type C, e.g. PMMA C H 2 C n O O µ i CH 3

9 Polymer Dynamics while LAOS G, G [Pa] Oscillatory Shear Freq [Hz] 1,4-cis-polyisoprene: dipole moment along the backbone (A-type) G G Mechanical shear ε Dielectric Spectroscopy ,46 ( ) ε ω = ε + HN Freq [Hz] ε without shear 50%, 11,45 Hz 100%, 11,45 Hz α ( 1+ ( iωτ HN ) ) β PI 54 PI 68 PI 79 0, ,42 ε ( ε ) ( ε) 0,40 ( ε) , γ 0 0, M w [kg/mol]

10 Dielectric Spectroscopy of hybrid Materials (Cooperation with Dr. Amir Fahmi, University of Nottingham) Hybrid Polystyrene-Poly(4vinylpyridine) Block Copolymers Nanocomposites (PS-P4VP) P S P Gold nanoparticels (d Particels 3 10 nm) N P n N P TEM images of lamellar hybride PS-P4VP Nanocomposites after LAOS (A. Fahmi et al., Macromolecules, 2009)

11 In situ Mechanical and Dielectric Behaviour (Mechnical Shear:? M /2p = 1 Hz,? 0 = 50%, T = 170 C) FT-Rheology: Fit: I 3/1 = I 3/1 + A*(1-exp(-x/t M ) ß ) t M = 5900 s ß M = 0.74 In situ Rheo-Dielectric:? D /2p = 10 Hz Fit: y = A*exp(-x/t M ) ß t D = 2400 s ß M = PS-P(4VP)-Au-Cyl-While LAOS streched exponetial 9.00E E-011 PS-P(4VP)-Au-Cyl-While LAOS streched exponential E-011 1E LAOS Shear flow σ' [S/cm] 6.00E E E-011 σ' [S/cm] 1E-7 1E-8 1E-9 1E-10 ω D /2π = 10 Hz Cyl-Before LAOS-170 C Cyl- After LAOS-170 C Random (Before) Parallel (After) 3.00E E E-011 1E-11 1E Freq. [Hz] time [s] time [s]

12 Design NMR-Mandhala for Rheo-NMR 16 mag. Lit.: P. Blümler, H.P. Raich, Concepts Mag. Reson. B, 23 B

epoxy resin intensity / % 30 25 20 15 10

13 Setup and Application New Halbachmagnet and NMR probe Cross-linking kinetic of epoxy resin intensity / % t / ms time / min time / ms 1' 36' 1h11 1h46 2h21 2h57 3h32 4h07 4h42 5h18 5h53 11h4 17h3 23h3 γ Cγ 1/ T 6 r ( 3J ( ω = 0) + 5J ( ω ) + 2J (2ω )) H 2 L L

14 The next step In situ: NMR and rheology Topics, e.g.: -shear induced Crystallization -effect of nanoparticles towards crystallization -vulcanization

MHz permanent magnet, NO liquid He, NO liquid N 2, basically NO running costs!

15 Cheap (!) in situ NMR: Bench-top MR-NMR Bench-Top, Medium-Resolution NMR System (0,1 ppm) 20 MHz permanent magnet, NO liquid He, NO liquid N 2, basically NO running costs! Separate lock channel Prototype version with Bruker Front-End Software: Bruker BioSpin s Topspin Electronic Shim System: 12 shims Fully digital filters and sample acqusition

16 Achievable resolution and 2D COSY! 1 H-NMR Ethanol Spectrum - 5 mm tube, 10 mm coil - resolution: 0.1 ppm (FWHM) - 1 scan (2 seconds) 2D COSY of Cinnamic Acid Ethyleste - 8 h measurement time

Combined methods in Rheology: Rheo-SAXS, Rheo-NMR and Rheo-Dielectric to bridge length and time scales

ANNUAL TRANSACTIONS OF THE NORDIC RHEOLOGY SOCIETY, VOL. 19, 2011 Combined methods in Rheology: Rheo-SAXS, Rheo-NMR and Rheo-Dielectric to bridge length and time scales Thomas Meins 1, Kyu Hyun 2, Karl-Friedrich