Dynamic Study of N'N-dimethylparanitroaniline encapsulated in Silicalite-1 matrix using neutron spin-echo spectroscopy

Deu Bhange (1) , Catherine Dejoie (1) , Florence Porcher (2) , Natalie Malikova (3) , Pauline Martinetto (1) , Eric Dooryhee (1) , Michel Anne (1)

1 NEEL - MRS - Matériaux, Rayonnements, Structure
2 LLB - UMR 12 - Laboratoire Léon Brillouin
3 PECSA - Physicochimie des Electrolytes, Colloïdes et Sciences Analytiques

The present work focuses on the dynamic studies of N'N-dimethyl- paranitroaniline (dmpNA) encapsulated in silicalite zeolite. Quasielastic neutron scattering (QENS) experiments are carried out using neutron spin-echo technique. Polarisation of the scattered neutron beam is measured at carefully chosen values of Q=0.35, 0.9, 1.1 and 1.45 A -1 at xed T=298 K and at xed Q=0.9 A -1 at 150, 200, 250 and 298 K. This gives insight into the motion and the related activation energy of the guest dmpNA molecule. The quasielastic signal observed in the present system within the time range considered is due to fast local rotational motions of protons of the end methyl groups. The results are in good agreement with the dynamics of methyl group rotations reported in the literature by back- scattering QENS technique.

Domaines: Science des matériaux [cond-mat.mtrl-sci]

Deu Bhange, Catherine Dejoie, Florence Porcher, Natalie Malikova, Pauline Martinetto, et al.. Dynamic Study of N'N-dimethylparanitroaniline encapsulated in Silicalite-1 matrix using neutron spin-echo spectroscopy. The European Physical Journal. Special Topics, 2010, 189, pp.279-284. ⟨10.1140/epjst/e2010.01333-9⟩. ⟨hal-00717726⟩