soft matter group philosophy define projects, complimentarity, mobility and international...
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Soft Matter
Group philosophyDefine projects, complimentarity, mobility and international collaborations,visitors, group meetings, fundingInfrastructure with expertise (basis for further development)
Members (senior)G. FytasG. Petekidis D. Vlassopoulos
FORTH people:A. Larsen, technicianU. Jonas, Researcher AB. Loppinet, Researcher B
Current funding: EU (ITN, NoE, LSI), limited industrial
Collaborations: US, Canada, Japan, Korea, France, UK, Germany, Belgium
Tailoring the flow of soft matter molecular design: synergy of chemistry, modeling, physical
expt
HardSoft
Com
ple
xit
y -
tu
nab
ility
ThermodynamicsDynamic arrest
Structure / dynamicsRheology
D. Vlassopoulos UoC-MST & FORTH-IESL
Viscoelasticity of entangled polymers
polymers with free ends
State-of-the-art: from Edwards over deGennes to Doi and McLeish
Tube modelPlateau modulus G=ρRT/Me
Linear: reptation etcStar: arm retraction
Viscoelasticity of entangled polymers
polymers with free ends
State-of-the-art: from Edwards over deGennes to Doi and McLeish
Q: polymers without free ends ?
Tube modelPlateau modulus G=ρRT/Me
Linear: reptation etcStar: arm retraction
Ring polymers
Roovers, NRC, 1985
Pure linear melt and melt of ring PS (no plateau)
τe
0.43
Power-law stress relaxation of entangled rings
Kapnistos et al, Nat. Mat. 2008
M. Rubinstein, UNC, 2003
Key: Critical fractionation toobtain pure rings(T. Chang, Pohang Univ., 2000)
t [s]
0.0001 0.001 0.01 0.1 1 10 100 1000
G(t
) [P
a]
1e+0
1e+1
1e+2
1e+3
1e+4
1e+5
1e+6
1e+7
ring 81kG(t) prediction rubinstein 81kring 38kG(t) prediction rubinstein 38kring 24kG(t) prediction rubinstein 24k
R. Pasquino
Linear ‘contaminant’ chainpenetrates rings maximizingentropy and percolating
New PI rings 24, 38, 81 K: Hadjichristidis et al, Univ. Athens
van Megen and Underwood, PRE 1994
Colloidal Glasses
Mason, Weitz, PRL, 1995
State-of-the-art: HS from Pusey over Götsche to Cates-Fuchs-Weitz
van Megen and Underwood, PRE 1994
Colloidal Glasses
Mason, Weitz, PRL, 1995
State-of-the-art: HS from Pusey over Götsche to Cates-Fuchs-Weitz
Q: effects of softness, particle architecture
Star polymers
Roovers, Hadjichristidis, 1993Gauthier, U. Waterloo, 2007
Binary star mixtures
Single glass Double glass
Asymmetric glass
Attractiveglass
Liquid(Ergodic)
C2
Single glass Double glass
Asymmetric glass
Attractiveglass
Liquid(Ergodic)
C2
Scale with softness S=δf/Na
with Stiakakis, Erwin, Cloitre, JCPM 2011
with Mayer, Stiakakis, Likos, Zaccarelli, Sciortino, Nat. Mat. 2008
10-6 10-4 10-2 100 102
100
101
102
103
[P
a]
[s-1].
1.0
Single star glass flow
Key: interpenetrability
П~R/√f
Rogers et al, PRL 2008
with B.Erwin,
M. CloitreJOR 2010, SM 2010PRE 2011
Cloitre
G. G. FullerC. F. Brooks et al., Langmuir, 1999, 15, 2450
ISR: Interfacial Stress Rheometer
Interfacial Rheology and Dynamics
State-of-the-art: from Gibbs-Langmuir over Plateau to Fuller-Vermant
Q: tailor film rheology (molecular design), ‘transfer’ 3D problems to 2D
G. G. FullerC. F. Brooks et al., Langmuir, 1999, 15, 2450
ISR: Interfacial Stress Rheometer
Interfacial Rheology and Dynamics
State-of-the-art: from Gibbs-Langmuir over Plateau to Fuller-Vermant
Q: tailor film rheology (molecular design), ‘transfer’ 3D problems to 2D
25 30 35 40 45 500
4
8
12
16
20
31 32 33 34 35
2
4
(m
N m
-1)
A (Å molecule-1)
F12H12 F11H1-core-H12 F12H20
(m
N m
-1)
A (Å2 molecule-1)
T = 20 °C
transition
0.1 1 10
0.1
1
T = 20 °C
G''
G'
G',
G''
(mN
m-1
)
f (rad s-1)
10 mN m-1
8 mN m-1
6 mN m-1
4 mN m-1
2 mN m-1
F12H12
fluorocarbon diblocks
colloidal particles
L. deViguerie, C. Christopoulou, C. Klein, R. Berger, C. Clark, K. Muellen, N. Vogel, K. Landfester and U. Jonas