NG-3 SANS: Tri-block Copolymer Monomer to Micelle Transitions

with Change in Temperature

Red Group

P85 Phase Diagram

Reference: K. Mortensen, J. Phys., Condens. Matter 8, A103 (1996)

P85 Phase Diagram

Reference: K. Mortensen, J. Phys., Condens. Matter 8, A103 (1996)

PEO

PEO

PEO-Hydrophobic

P-85 Pluronics

Collapsed Fully Extended

Why SANS?

Structural InformationTransition TemperatureSize of Aggregates

Compositional Information Is the core completely PPOHow solvated are the polymer “whiskers”

velocity selector collimation

samplearea

area detectorbeamshutter

15 m 15 m

coldneutrons

BEAM BEAM ON OFF

Why use two detector distances?

Scan whole Q-range

0.0239 – 0.4742Å-1 for small source to sample

0.0035 – 0.0491 Å-1 for large source to sample

Less detector distances allow for many samples

NG-3 System Overview

P85 10 wt.% 10 C

2gqRx Rg=1.16 nm

Scale = 0.36 2

2 12xxeZV

dd x

m

Scale F(Rg)

P85 Phase Diagram

Reference: K. Mortensen, J. Phys., Condens. Matter 8, A103 (1996)

P85 Phase Diagram

Reference: K. Mortensen, J. Phys., Condens. Matter 8, A103 (1996)

dShell= 2.7 nm

P85 10 wt.% 50 oC

RCore= 4.7nm

= 0.25

PolyCore=0.15

10 oC

50 oC

)()( qSqFndd

p

P85 Phase Diagram

Reference: K. Mortensen, J. Phys., Condens. Matter 8, A103 (1996)

P85 Phase Diagram

Reference: K. Mortensen, J. Phys., Condens. Matter 8, A103 (1996)

D2O:PEO in shell 28.5

Agg. Number 78

dShell= 2.7 nm

P85 10 wt.% 25 oC

RCore= 4.7nm

= 0.25

10 oC

50 oC

MonomerpCoreShellp qFnqSqFn

dd )()()(

P85 Phase Diagram

Reference: K. Mortensen, J. Phys., Condens. Matter 8, A103 (1996)

P85 Phase Diagram

Reference: K. Mortensen, J. Phys., Condens. Matter 8, A103 (1996)

Rg=1.16 nm

Scale = 0.36

25 oC

Conclusions

• Using SANS the temperature-dependent morphology of P85 was characterized

• Contrast-matching may allow confirmation of the modeling results

Acknowledgements

Special thanks to:Paul Butler and Joe DuraBoualem Hammouda & Steve KlineEveryone at NCNR

Questions?