摘要

Two applications of quasi-static magnetic field gradients in nuclear magnetic resonance spectroscopy are discussed. The first application is conformon transport in the quasi-ordered pi-conjugated polymer, poly(4-methylthiazole-2,5-diyl). With the assistance of proton longitudinal relaxation (R-1) dispersion measurements of the powdered polymer sample, which showed a omega(-1/2) dependence because of one-dimensional fluctuations in its linear pi-conjugation, one can determine the diffusion coefficient, characteristic transport length, and local magnetic field gradient using proton transverse relaxation (R-2) dispersion measurements under an internal magnetic field gradient and numerical simulations of the spin dynamics. The second application is to demonstrate the possibility for one-dimensional magnetic resonance imaging using an external static magnetic field gradient from a neodymium ferromagnet. High-order primary spin echoes were observed in three-layered thin films consisting of poly(dimethylsiloxane) [PDMS]/poly(tetrafluoroethylene)/PDMS, whereas a comb-like dip in the magnetization amplitude was observed in the quadrature echo spectrum, which means the NMR experiments using the static magnetic field gradient from the ferromagnet were successfully performed. This result could lead to low-cost magnetic resonance imaging instruments for thin films. The possibility of spectral density imaging is also discussed from the viewpoint of variable independence between the static and gradient magnetic fields. Polymer Journal (2012) 44, 855-862; doi:10.1038/pj.2012.101; published online 6 June 2012

  • 出版日期2012-8

全文