hierarchical structure and dynamics of...

Hierarchical Structureand Dynamics of

Softmatters

Hideki SetoNeutron Scattering Laboratory, IMSS, KEK

Softmatter (=Soft Condensed Matter)

Polymers Liquid Crystals

ColloidsAmphiphilic molecules

Amphiphilic Polymer

Emulsion

Polymer Liquid Crystal

Liquid Crystal ColloidLyotropic Liquid Crystal

Liquid Crystal Polymer

directional order

water oil

hydrophobichydrophilic

Polymers Liquid Crystals

ColloidsAmphiphilic molecules

Applications of Softmatters

engineering plastic

film

thermography

display

detergent

soappaint

cosmetics

Softmatters in LivesPolymers Liquid Crystals

ColloidsAmphiphilic molecules

phospholipid

glycolipid

bio-membrane

blood

protein

DNA

cell

bio-membrane

10-9 10-6 10-3 m

membrane protein

peptide

Hierarchical Structureof Biological System

lipid membranephospholipid

10-9 10-6 10-3 m

transparent liquidmicroemulsiono/w dropletamphiphilicmolecules

Hierarchical Structureof Softmatters

Hierarchical Structure andDynamics

d(Å)

103

100

10-3

10-6

10-9

10-12

100 101 102 103

Two-level motion

Local motion

(!-process)

Segmental motion

("-process)

CooperativeD iffusion

Reptation

104

Methods to investigateSoftmatters

Small-Angle X-ray Scattering Small-Angle Neutron Scattering Neutron Spin Echo

X-ray Reflectometer/GI-SAXS Neutron Reflectometer Neutron Total Scattering

10<d<1000Å, time slice(Δt>10ms) 20<d<3000Å, contrast variation 5<d<1000Å, quasi-elastic(ΔE~10neV)

10<d<1000Å, surface structure 10<d<700Å, air/liquid interface 0.06<d<800Å, wide Q-range

PF

ISSP/JAEAISSP/JAEA

J-PARC

J-PARC

SPring-8

Structures of microemulsions

Surfactant

Water Oil

Lamellar

Spherical MicellesInverted Micelles

Irregular Bicontinuous

Hexagonal

Inverted CubicCubic

Cylindrical Micelles

Bending energy

R1

R2

mean curvature H =1

2

1

R1+1

R2

!

"#

$

%&

Gaussian curvature K =1

R1

1

R2

Ebend = '(H (1

Rs)2+'K

)

*+

,

-./ dS

spontaneous curvature

saddle-splay modulusbending modulus

W. Helfrich, Z. Naturforsch. C28 (1973) 693

AOT+D2O+decane

Effects of T and P seem to be the same

Temperature induced phase transition

Pressure?

BL-15A, Photon Factory, KEK

P-dependence of SAXS

droplet

lamellar

T- and P-dependences of inter-dropletpotential

Pressure-induced phase transition

P- and T- dependence of membranefluctuation were investigated by NSE

Kawabata, Seto et al., PRL 2004, JCP 2007

iNSE at JRR-3M, JAEA (ISSP)

P- and T-variations of I(Q,t)

T

P

ambient temperature/pressure

I(Q,t)/I(Q,0)=exp(-DeffQ2t)

Bending modulus

Effects of Pressure and Temperature

Temperature

Pressure

Rs(spontaneous curvature)

κ(bending modulus)

decrease

decrease increase

decrease

Future works to be investigated at CMRC?

for example: “raft” structure of bio-membrane

How the “raft”structure is organized?

How the membraneproteins work?

Hybridization of softmatters

SANS/SAXS/NSE XR/NR/GI-SAS

polymer supported model bio-membrane

Tanaka & Sackmann, Nature 2005

phase separation of a mixture of lipids

Vietch & Keller, PRL 2002

Yamada et al., submitted

How the “raft”structure is organized?

How the membraneproteins work?