Session H13: Colloid and Polymer Interfaces

11:15 AM–1:39 PM, Tuesday, March 14, 2006
Baltimore Convention Center Room: 305

Chair: Hai-Lung Dai, University of Pennsylvania

Abstract ID: BAPS.2006.MAR.H13.6

Abstract: H13.00006 : Quasielastic neutron scattering study of the dynamics of 1,3-diphenylpropane grafted to the pore surface of MCM-41

12:15 PM–12:27 PM

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Authors:

Edward Kintzel
Kenneth Herwig
Michelle Kidder
A.C. Buchanan
Phillip Britt
(Oak Ridge National Laboratory)

Alan Chaffe
(Monash University)

An initial study of the dynamics of 1,3-diphenylpropane (DPP, $\equiv$Si-O-C$_{6}$H$_{4}$(CH$_{2})_{3}$C$_{6}$H$_{5})$ attached to the surface of the mesoporous silica MCM-41 has been carried out using quasielastic neutron scattering. Measurements of the elastic intensity were carried out in the temperature range 50-380 K and indicate a trend in DPP dynamics with changing grafting density and pore size. Full quasielastic scans over an energy range of $\pm$ 17 $\mu$eV were carried out at temperatures of 240 K, 280 K, and 320 K. Initial analysis employed a stretched exponential to model the Fourier transformed data in the time domain. An average relaxation time, defined as $<\tau >$ = ($\tau$/$\beta )\Gamma$(1/$\beta )$ where $\beta$ is the stretched exponent in the model, shows a dependence on temperature, pore size, and DPP grafting density. Molecular dynamics simulations using a model for DPP grafted onto the surface of MCM-41 was compared with the experimental results.

To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2006.MAR.H13.6