Non-Linear Behavior of Entangled Multiple Branch Point Systems

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• Soft Matter
• Group philosophy
• Define projects, complimentarity, mobility and
  international collaborations,
• visitors, group meetings, funding
• Infrastructure with expertise (basis for further
  development)
• Members (senior)
• G. Fytas
• G. Petekidis
• D. Vlassopoulos
• FORTH people
• Larsen, technician
• U. Jonas, Researcher A
• B. Loppinet, Researcher B
• Current funding EU (ITN, NoE, LSI), limited
  industrial

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Tailoring the flow of soft matter
molecular design synergy of chemistry, modeling,
physical expt
Hard
Complexity - tunability
Structure / dynamics Rheology
Thermodynamics Dynamic arrest
D. Vlassopoulos UoC-MST FORTH-IESL
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Viscoelasticity of entangled polymers
polymers with free ends
Tube model Plateau modulus G?RT/Me Linear
reptation etc Star arm retraction
State-of-the-art from Edwards over deGennes to
Doi and McLeish
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Viscoelasticity of entangled polymers
polymers with free ends
Tube model Plateau modulus G?RT/Me Linear
reptation etc Star arm retraction
State-of-the-art from Edwards over deGennes to
Doi and McLeish
Q polymers without free ends ?
Ring polymers Roovers, NRC, 1985
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Pure linear melt and melt of ring PS (no plateau)
Power-law stress relaxation of entangled rings
Key Critical fractionation to obtain pure
rings (T. Chang, Pohang Univ., 2000)
te
0.43
Kapnistos et al, Nat. Mat. 2008
M. Rubinstein, UNC, 2003
R. Pasquino
Linear contaminant chain penetrates rings
maximizing entropy and percolating
New PI rings 24, 38, 81 K Hadjichristidis et
al, Univ. Athens
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Colloidal Glasses
van Megen and Underwood, PRE 1994
Mason, Weitz, PRL, 1995
State-of-the-art HS from Pusey over Götsche to
Cates-Fuchs-Weitz
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Colloidal Glasses
van Megen and Underwood, PRE 1994
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,
1993 Gauthier, U. Waterloo, 2007
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Binary star mixtures
Scale with softness Sdf/Na
with Stiakakis, Erwin, Cloitre, JCPM 2011
with Mayer, Stiakakis, Likos, Zaccarelli,
Sciortino, Nat. Mat. 2008
Single star glass flow
Key interpenetrability ?R/vf
Cloitre
with B.Erwin, M. Cloitre JOR 2010, SM 2010 PRE
2011
Rogers et al, PRL 2008
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Interfacial Rheology and Dynamics
G. G. Fuller
ISR Interfacial Stress Rheometer
C. F. Brooks et al., Langmuir, 1999, 15, 2450
State-of-the-art from Gibbs-Langmuir over
Plateau to Fuller-Vermant
Q tailor film rheology (molecular design),
transfer 3D problems to 2D
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Interfacial Rheology and Dynamics
G. G. Fuller
ISR Interfacial Stress Rheometer
C. F. Brooks et al., Langmuir, 1999, 15, 2450
State-of-the-art from Gibbs-Langmuir over
Plateau to Fuller-Vermant
Q tailor film rheology (molecular design),
transfer 3D problems to 2D
colloidal particles
fluorocarbon diblocks
L. deViguerie, C. Christopoulou, C. Klein, R.
Berger, C. Clark, K. Muellen, N. Vogel, K.
Landfester and U. Jonas