1.
Phys Rev E Stat Nonlin Soft Matter Phys
; 75(4 Pt 1): 041802, 2007 Apr.
Artigo
em Inglês
| MEDLINE
| ID: mdl-17500914
RESUMO
We here develop a theory for the effect of shearing flow on residual proton dipole-dipole interactions for polymer melts. The model is based on the use of correlation functions which derive from the return to origin probability for polymers reptating in the tube of surrounding constraints. Using Doi-Edwards theory we calculate the spin-echo response under equilibrium conditions and then consider the effect of a shearing flow which deforms the tube, finding that there exists a strong dependence of transverse relaxation on Weissenberg number. The results are compared with NMR measurements of shear-perturbed proton T2 relaxation in 494kDa poly (dimethylsiloxane).