Soft Matter Studies with X-rays

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1 Soft Matter Studies with X-rays Theyencheri Narayanan European Synchrotron Radiation Facility Structure from Diffraction Methods, Eds. D.W. Bruce, D. O Hare & R.I. Walton, (Wiley, 2014) Soft-Matter Characterization, Eds. R. Borsali & R. Pecora (Springer, 2008) Slide: 1

2 Outline What is Soft Matter? Some general features Different X-ray techniques employed Self-assembly & complexity Out-of-equilibrium phenomena Summary and outlook Slide: 2

3 What is Soft Matter? Soft matter is a subfield of condensed matter comprising a variety of physical states that are easily deformed by thermal stresses or thermal fluctuations. They include liquids, colloids, polymers, foams, gels, granular materials, and a number of biological materials. These materials share an important common feature in that predominant physical behaviors occur at an energy scale comparable with room temperature thermal energy. At these temperatures, quantum aspects are generally unimportant. Pierre-Gilles de Gennes, who has been called the "founding father of soft matter," [1] received the Nobel Prize in physics in 1991 for discovering that the order parameter from simple thermodynamic systems can be applied to the more complex cases found in soft matter, in particular, to the behaviors of liquid crystals and polymers. Matière molle» Madeleine Veyssié Slide: 3

4 Soft Matter: Encounter in everyday life Sustainable development and supply of consumer products Slide: 4

5 What is Soft Matter? Materials which are soft to touch characterized by a small modulus (energy/characteristic volume), typically times lower than an atomic solid like aluminum. A significant fraction of consumer products fall in this category. Soft matter science is an interdisciplinary field of research where traditional borders between physics and its neighboring sciences such as chemistry, biology, chemical engineering and materials science disappear. Soft Matter studies seek to address the link between microscopic structure/interactions and macroscopic properties. Slide: 5

Soft Matter Characteristics Dominance of

fluctuations (~ k B T) Characteristic size

modulus, G ~ Energy/Free volume» 10 9 10 12

viscoelastic Soft implies: (1) high degree of

6 Soft Matter Characteristics Dominance of entropy Strong influence of thermal fluctuations (~ k B T) Characteristic size scale or microstructure ~ nm Shear modulus, G ~ Energy/Free volume» smaller Low shear modulus (G)» soft and viscoelastic Soft implies: (1) high degree of tailorability (2) lack of robustness Multi-scale out-of-equilibrium systems Slide: 6

7 3 main ingredients of soft matter Soft Matter Triangle Flexible side Harder side Selective side Slide: 7

8 Soft Matter: Increasing levels of complexity Elucidating the pathways of self-assembly O. Ikkala and G. Brinke, Chem. Commun., (2004) Slide: 8

9 Impact of Soft Matter in Condensed Matter Physics Over the last 40 years Critical Phenomena (static and dynamic) Freezing, glass transitions, etc. Fractal growth (e.g. colloid aggregation) Self-organized criticality (granular matter) Soft Matter constitutes a significant fraction of modern day Nanoscience/Nanotechnology. Slide: 9

10 Synchrotron Techniques used in Soft Matter Slide: 10

11 Synchrotron Radiation Studies of Soft Matter High spectral brilliance or brightness Real time studies in the millisecond range, micro/nano focusing and high q resolution Time-resolved SAXS, WAXS, micro-saxs, USAXS, etc. High detectivity for studying extremely dilute systems (f < 10-6 ) Partial coherence Equilibrium dynamics using the coherent photon flux (for concentrated systems) Photon correlation spectroscopy (XPCS) Continuous variation of incident energy Contrast variation of certain heavier elements, e.g. Fe, Cu, Se, Br, Rb, Sr, etc. Anomalous SAXS Complementary imaging techniques X-ray microscopy, micro and nano tomography, etc. Slide: 11

12 Small-Angle X-ray Scattering (SAXS) l vacuum q sample beamstop detector 4 q sin( q / l Measured Intensity: 2) I S i 0 T r e DW d dw Differential scattering cross-section i 0 - incident flux T r - transmission e - efficiency DW - solid angle I( q) d dw 1 V Scat d dw Beamline ID02 Slide: 12

13 I(q) (mm -1 ) 10 6 SAXS from dilute spherical particles Guinier region Porod q Silica particles (f ~ 0.01, size ~ 600 nm, p ~ 2%) Model (R Mean =303 nm, R =6.2 nm & Dq=0.001 nm -1 ) q (nm -1 ) Slide: 13

14 SAXS from spherical colloidal particles I( q) N F( q) S( q) N particle number density, F(q) single particle scattering function, S(q) structure factor of interactions Thomson scattering F( q) A( q) A * ( q) sin qr A( q) 4 re [ ( r) m] r 0 qr * r e S 2 dr (r) radial electron density r e classical electron radius =2.82x10-15 m scattering length density for homogeneous particles * D I( q) * * S m * N( D V ) 2 P( q) contrast S( q) V volume of the particle P(q) form factor Calculation of S(q) involves approximations (e.g. Percus-Yevick closure) Slide: 14

15 Size scales probed by SAXS & related techniques Nanoworld Microworld m 10-9 m 10-8 m 10-7 m 10-6 m 10-5 m 10-4 m 10-3 m 10-2 m 0.1 nm Soft x-ray 1 nanometer (nm) 0.01 mm 10 nm 2 q Ultraviolet 0.1 mm 100 nm Visible 1,000 nanometers = 1 micrometer (mm) Infrared 0.01 mm 10 mm 0.1 mm 100 mm Microwave 1,000,000 nanometers = 1 millimeter (mm) 1 cm 10 mm Colloids Polymers Surfactants Liquid crystals Etc. Slide: 15

16 Size scales probed by SAXS & related techniques Nanoworld Microworld m 10-9 m 10-8 m 10-7 m 10-6 m 10-5 m 10-4 m 10-3 m 10-2 m 0.1 nm Soft x-ray 1 nanometer (nm) 0.01 mm 10 nm 2 q Ultraviolet 0.1 mm 100 nm Visible 1,000 nanometers = 1 micrometer (mm) Infrared 0.01 mm 10 mm 0.1 mm 100 mm Microwave 1,000,000 nanometers = 1 millimeter (mm) 1 cm 10 mm Colloids Polymers Surfactants Liquid crystals Etc. Slide: 16

17 I(q) (mm -1 ) I(q) (mm -1 ) Differential scattering cross-section per unit volume Form & Structure Factors I( q) * N( D V) 2 P( q) S M ( q) Experimental P(q), polydisperse & S (q) within Percus-Yevick (PY) approximation 10 3 Form Factor Fit f [S(q) PY ] f < q (nm -1 ) f C [I(0)] q (nm -1 ) Slide: 17

I(q) (mm -1 ) I(q) (mm -1 ) Differential scattering cross-section per unit volume Form & Structure Factors I( q) * N( D V) 2 P( q) S M ( q) Experimental P(q), polydisperse & S (q) within

18 I(q) (mm -1 ) I(q) (mm -1 ) Differential scattering cross-section per unit volume Form & Structure Factors I( q) * N( D V) 2 P( q) S M ( q) Experimental P(q), polydisperse & S (q) within Percus-Yevick (PY) approximation Crystalline order 10 3 Form Factor Fit f [S(q) PY ] f < q (nm -1 ) f C [I(0)] q (nm -1 ) Slide: 18

19 X-ray Photon Correlation Spectroscopy (XPCS) Beamline ID10 Silica microspheres in water d=0.49±0.02mm, q=0.09 nm -1 1 D C q 0 2 Slide: 19

20 Multi-speckle XPCS Slide: 20

21 Combination with shear flow Couette cell X-ray beam Slide: 21

22 Grazing Incidence Small-Angle X-ray Scattering (GISAXS) q x,y,z cos a f 2 cosa f l cosq cosa cosq sina sina i f sinq cosa sinq f f i i f f z q z a f q f q y a i x y Beamline ID10 Slide: 22

of molecules, macromolecules and nanoparticles - Bio-mimetic systems & Bio-mineralization

23 Soft Interfaces Scattering - Surface structure of simple and complex fluids (colloid, gel, sol, ) - Morphology and crystalline structure of thin organic and inorganic films - 2D organization of molecules, macromolecules and nanoparticles - Bio-mimetic systems & Bio-mineralization Langmuir Buried films interfaces Z a P, A, T b y b a gas-liquid liquid-liquid b y b liquid-solid Slide: 23

Penetration depth, Λ, 1/A Å Varying the penetration depth 10 3 10 2 surface

0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 Grazing angle, a/a c Dα i < 0.

24 Penetration depth, Λ, 1/A Å Varying the penetration depth surface α i 0.1 at 8 kev λ=1.55 Å Soft Interfaces Scattering bulk α / α C Grazing angle, a/a c Dα i < 0.1α i β Λ(ρ, α) (2) d f FILM SUBSTRATE (1) d f α Elements distribution Complex fluids Slide: 24

$Micro-diffraction (ID13) Skin-core morphology of$ local nanostructure to the fiber mechanical

25 Micro-diffraction (ID13) Skin-core morphology of high performance fibers E.g. Kevlar Correlate the local nanostructure to the fiber mechanical properties. Elucidating the local nanostructure Slide: 25

26 I(q) (m m -1 ) SAXS/WAXS from Semi-crystalline polymers 10 0 SAXS WAXS amorphous crystalline q (nm -1 ) Slide: 26

$Scanning Micro-diffraction on HDPE spherulites 12.5 kev, 1.$

27 Scanning Micro-diffraction on HDPE spherulites 12.5 kev, 1.5 micron spot high density poly-ethylene spherulites under polarized light banded structures indicating long range order SAXS/WAXS patterns line scans across the center reveal information on crystallite orientation Rosenthal M. et al., Angewandte Chemie, (2011) Slide: 27

$Micro-diffraction on HDPE spherulites Azimuth/Intensity vs$ normal of the base plane of crystalline lamellas orientation of

28 Micro-diffraction on HDPE spherulites Azimuth/Intensity vs Distance from the center in mm 35 tilt between c-axis and the normal of the base plane of crystalline lamellas orientation of b-axis aligned with growth direction chirality can be determined Slide: 28

$Coherent X-ray Diffractive$ of non-crystalline objects,

29 Coherent X-ray Diffractive Imaging (CDI) 2D and 3D imaging of non-crystalline objects, biological samples with nanometers resolution Lensless imaging technique Thick or small samples (single molecules) SEM image Reconstruction pixel 24 nm 3D reconstruction Slide: 29

$diffraction pattern 3D$ reconstruction H.

30 CDI of Biological Specimen Phases encoded by over sampling of the diffraction pattern 3D reconstruction H. Jiang et al., PNAS (2010) Slide: 30

31 Spontaneous self-assembly Slide: 31

Motivation: understanding self-assembly in nature Kinetics of

material stability, cell trafficking (drug delivery), detergency, etc.

complexes formed: kinetic pathways to (non-)equilibrium?

32 Motivation: understanding self-assembly in nature Kinetics of self-assembling systems understanding of properties and functionalities material stability, cell trafficking (drug delivery), detergency, etc. Complexity Micelles Vesicles Lipid-DNA complex Cell How are these complexes formed: kinetic pathways to (non-)equilibrium? How can these complexes be tuned and manipulated to new materials (e.g. biomedical/pharmaceutical applications)? Slide: 32

33 Spontaneous self-assembly of micelles and vesicles E.g. surfactants, lipids or block copolymers Large variety of equilibrium structures Dynamics of formation is very little explored Self-assembly of micelles and vesicles monomers micelles anionic vesicle? spherical micelles Rate-limiting steps» predictive capability cationic? Kinetic pathway: stopped-flow rapid mixing & time-resolved SAXS Slide: 33

34 Stopped-Flow Mixing Device Rapid mixing of reactants in turbulent flow through a mixer Solenoid valve at the exit to stop the flow of the mixture Deadtime ~ a few millisecond Beamline ID02@ESRF Slide: 34

35 P I(Q) Spontaneous self-assembly of block copolymer micelles Rapid jump in solvent selectivity / Interfacial tension Q [A -1 ] 14.5 ms 24.5 ms ms ms ms 240 s Unimer Reservoir Model fits» mean aggregation number, P mean Unimer DMF? Micelle Poly(ethylene-propylene) - poly(ethylene oxide) DMF/water time [milli seconds] R. Lund, et al., PRL, 102, (2009) Slide: 35

I(q) (mm -1 ) Self-assembly of unilamellar

10-2 M 1 10-3 M 2 10-4 M 1 10-5 < 4 ms 10-1 10 0

36 I(q) (mm -1 ) Self-assembly of unilamellar vesicles mm M 1 M 2 < 4ms M 2 M 1 +M M M M < 4 ms q (nm -1 ) disk-like disk-like objects with: R = 7.5nm; H = 4.8nm size of initial disks: x size rod-like micelle T.M. Weiss et al., PRL (2005) Langmuir (2008) Transient disk-like micelles are formed within the mixing time (< 4 ms) Slide: 36

37 I(q) (mm -1 ) Growth of disk-like micelles s s 0.58 s disk area 2 R s 0.06 s s RC 2 1 R 2 C 4 1 C Radius of curvature q (nm -1 ) Bending energy vs Edge energy & - bending moduli L - line tension E bend 4 2 RC At the closing state: R max E edge 4 2LRC 2 L 1 C 2 R 4 2 T.M. Weiss et al., PRL (2005) Langmuir (2008) Slide: 37

I(q) (mm -1 ) 10 3 2.68 s Free 10 energy of a bend bilayer 2 0.88 s 0.58 s 10 1 10 0 Growth of disk-like micelles 0.

01 s disk area 2 R 10-1 ln(f/a [kt/nm 2 ]) 10-2 10-3 10-4 Disk, lense 10-1 10 0 Bending energy vs q (nm -1 )

38 I(q) (mm -1 ) s Free 10 energy of a bend bilayer s 0.58 s Growth of disk-like micelles 0.24 s 0.06 s 0.01 s disk area 2 R 10-1 ln(f/a [kt/nm 2 ]) Disk, lense Bending energy vs q (nm -1 ) Vesicles Edge energy RC 2 1 R 2 C 4 1 C Radius of curvature & - bending moduli L - line tension E bend 4 2 RC At the closing state: R max E edge 4 2LRC 2 L 1 C 2 R 4 2 T.M. Weiss et al., PRL (2005) Langmuir (2008) Slide: 38

39 Soft matter self-assembly at interfaces α I 0 q X oil q Z water Beam travel path 70 mm I β b b y y b b Z a gas-liquid liquid-liquid a liquid-solid Interfacial cavities for reaction Slide: 39

Formation and Ordering of Gold Nanoparticles at

13 NPs with Ø 12 Å & 11 Å thick organic layer M.

40 Formation and Ordering of Gold Nanoparticles at the Toluene-Water Interface cluster-cluster separation, d 1 =180 Å particle-particle separation, d 2 = 34 Å Each cluster consists of 13 NPs with Ø 12 Å & 11 Å thick organic layer M.K. Sanyal et al., J. Phys. Chem. C, 112, 1739 (2008) Slide: 40

41 Formation and Ordering of Gold Nanoparticles at the Toluene-Water Interface Each cluster consists of NPs with Ø 12 Å & 11 Å thick organic layer M.K. Sanyal et al., J. Phys. Chem. C, 112, 1739 (2008) Slide: 41

42 Out-of-equilibrium Dynamics Slide: 42

, PRL (2008) This type of dynamics studies can be performed in the

43 Multi-speckle XPCS analysis Dynamics of tracer particles in a glass-forming liquid (b) (a) q Silica particles in propylene glycol 2 q C. Coronna et al., PRL (2008) This type of dynamics studies can be performed in the sub-millisecond range q [nm -1 ] Diffusive to ballistic dynamics near glass transition Slide: 43

44 Soft Matter: out-of-equilibrium dynamics Multi-speckle XPCS Slide: 44

H(t) / Ho Soft Matter: out-of-equilibrium

related to shelf-life of products 1.2 1 0.

45 H(t) / Ho Soft Matter: out-of-equilibrium dynamics Probing the dynamics of ageing: related to shelf-life of products Colloid-polymer mixture two-time correlation function Time (h) Gel Crossover of dynamic behavior large scale reorganization A. Fluerasu, A. Moussaid, et al., PRE(R) (2007) Slide: 45

46 UPBL9a: TRUSAXS Beamline SAXS/WAXS/USAXS Multiple detectors 32 m long and 2 m diameter Energy range: 720 kev Dq: 5x10-4 nm -1 (FWHM) q range: nm -1 Time res. 10 ms 2014 Sample-detector distance: m Slide: 46

UPBL9a: TRUSAXS Beamline SAXS/WAXS/USAXS Multiple detectors 32 m long and 2 m diameter Time (s) Energy range: 720 kev Dq: 5x10-4 nm -1 (FWHM) q range: 10-3 50 nm -1 Time

47 UPBL9a: TRUSAXS Beamline SAXS/WAXS/USAXS Multiple detectors 32 m long and 2 m diameter Time (s) Energy range: 720 kev Dq: 5x10-4 nm -1 (FWHM) q range: nm -1 Time res. 10 ms SAXS WAXS USAXS Stroboscopic 10-5 Sample-detector distance: m /q (nm) Slide: 47

48 Summary & Outlook High brilliance X-ray scattering is a powerful method to elucidate the non-equilibrium structure & dynamics of soft matter. Time-resolved scattering experiments in the millisecond range can be performed even with dilute samples. Combination of nanoscale spatial and millisecond time resolution makes synchrotron techniques unique in these studies. Challenges lie in the ability to investigate complex polydisperse systems with competing interactions. Experiments can be performed in the functional state of the system. The emphasis will be on quantitative studies made possible by the high detection capability and reduced radiation damage, and complemented by advanced data analysis. Slide: 48

Lecture 5: Macromolecules, polymers and DNA

Lecture 5: Macromolecules, polymers and DNA 1, polymers and DNA Introduction In this lecture, we focus on a subfield of soft matter: macromolecules and more particularly on polymers. As for the previous chapter about surfactants and electro kinetics,