Berlin 2012 – scientific programme

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DY: Fachverband Dynamik und Statistische Physik

DY 8: Glasses I (with CPP, talks by CPP)

DY 8.5: Talk

Monday, March 26, 2012, 16:30–16:45, C 243

Epoxy resins in confined geometry — •Anna Silex, Jörg Baller, and Roland Sanctuary — Laboratory of Physics of Condensed Matter and Advanced Materials, University of Luxembourg, 162A, Avenue de la Faiencerie, L-1511 Luxembourg

In order to exemplarily study the influence of confinement on the behavior of a widely used epoxy resin (Diglycidil Ether of Bisphenol A, DGEBA), we have filled mesoporous glasses with different pore radii with the low molecular weight liquid. Several confinement effects are known to take influence on the glass transition of small molecule liquids. Firstly, interactions between the glass former and the large internal surface of the porous glass lead to a slowing down of the molecular dynamics. Secondly, the confinement of the liquid molecules by the pores and the layer is generally known to accelerate the molecular dynamics. Finally, negative pressure building up in the pores due to the mismatching thermal expansion coefficients of the liquid and the porous glass is discussed to lead to a lower glass transition temperature compared to the pure materials. We present experimental results obtained for DGEBA-porous glass systems with stochastically modulated calorimetry and thermo-mechanical analysis. Thereby the focus is on the influence of the pore size on the glass transition behavior of the guest material but also on the macroscopic characteristics of the complete system as a result of the confinement. Differences between the thermal expansion of the empty and DGEBA filled samples are highlighted.