Application of nuclear magnetic resonance magic sandwich echo imaging to solid polymers.
A solid-state 1H nuclear magnetic resonance (NMR) imaging technique based on magic sandwich echoes (MSE) is described for obtaining spatial projections of solid polymer samples. The modification of MSE multiple echo detection is combined with short gradient pulses applied during the sandwich windows. This allows proton homonuclear decoupling in solids with dipolar couplings up to 50 kHz. For a rapid gating of the gradients a fast gradient pulse driver was constructed with switching times between 550 and 910 ns giving a maximum gradient strength of 330 mT/m. With our detection technique the spectral width can be doubled. One-dimensional projections and spatially resolved spectra of rigid polymer phantoms are presented. For contrast enhancement the use of the T1 relaxation time and the number of the magic sandwiches functioning as an adjustable magnetization filter discriminating between different strengths of the dipolar coupling is demonstrated.
Max-Planck-Institut für Polymerforshung, Mainz, Germany.
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Weigand
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Blümich
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Spiess
D017352:Echo-Planar Imaging / Q000379:methods*; D007089:Image Enhancement / Q000379:methods*; D011108:Polymers; D011522:Protons
D011108:Polymers; D011522:Protons