### Session H19: Solid Amorphous Polymers

8:00 AM–11:00 AM, Tuesday, March 17, 2009
Room: 320

Chair: Sergei Nazarenko, University of Southern Mississippi

Abstract ID: BAPS.2009.MAR.H19.10

### Abstract: H19.00010 : Rheological Scaling Relation for an Out-of Equilibrium Colloidal Solid

10:12 AM–10:24 AM

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#### Authors:

H. Henning Winter
(University of Massachusetts Amherst)

X. Wang
(Nanjing University, China)

G. Xue
(Nanjing University, China)

P. Sun
(Nankai University, China)

We explore scaling relations for the slow ripening of an out-of-equilibrium model colloidal solid that consists of clay particles that swell and exfoliate into randomly oriented clay sheets through the action of end-functionalized (sticky'') polymer molecules. A freshly mixed sample quickly forms a sample-spanning network structure that gradually approaches its equilibrium. The ripening process accelerates at elevated temperature. After rescaling (Rheol Acta 45:331-338, 2006), the complex modulus data $G$',$G$''(\textit{$\omega$}, $t_{r})$ from time-resolved mechanical spectroscopy (Rheol Acta 33:385-397, 1994) shows that, surprisingly, the growth function of the elastic modulus is the inverse of the decaying characteristic relaxation time. Parameter of the isothermal ripening process is the ripening time'', $t_{r}$. A single scaling function with two pronounced powerlaw regions, a fast ripening process ($\sim \quad t_{r}^{-2})$ followed by slow ripening ($\sim \quad t_{r}^{-1/2})$, defines the state of ripening and projects the time necessary to reach equilibrium.

To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2009.MAR.H19.10