Goldman-Shen experiment

Fig, 6.1.7. Pulse sequence and magnetization recovery of the Goldman-Shen experiment. Magnetization in the rigid (crystalline) domain is randomized in time to> V 2. Recovery of magnetization of the crystalline domains, R(f), due to transfer of magnetization from noncrystalline to crystalline domains is monitored at variable times t. 

In this section 10.2, we review the various solid-state NMR methods used to investigate interpolymer interactions, molecular motion and the spatial structure of a polymer blend. An interaction between component polymers affects the chemical shifts and lineshapes (see Section 10.2.2.1) and the molecular motions of the component polymers (see Section 10.2.2.2). In Section 10.2.3.1, microheterogeneity from 2 to 50 nm is studied by measuring spin diffusion indirectly from its effects on H spin-lattice relaxation. The spin-diffusion processes can also be monitored by several methods based on the Goldman-Shen experiment [8] (see Section 10.2.3.2). Homonuclear and heteronuclear two-dimensional correlation experiments reveal how and to what extent component polymers interact with each other (see Section... 

Various methods have been proposed for (1) and (3). In Section 10.2.3.2, methods for (1) based on the Goldman-Shen experiment [8] are reviewed. In Section 10.2.3.3, 2D NMR experiments, which enable us to detect the region of specific interpolymer interaction and the domain size on a scale of 2 nm, are discussed. In Section 10.2.3.4, heteronuclear cross-relaxation experiments between — H, electron to etc., which... 

Fig. 10.11. (a) Pulse sequence for the modified Goldman-Shen experiment with detection and (b) plots of H magnetization change versus square root of the spin-diffusion time for PVPh/PEO = 58/42 at 310 K. Straight lines are drawn through the initial linear portion of the data to determine the intercept time L. (Reprinted with permission from Ref. [34]. 1992 American Chemical Society, Washington, DC.)... 

Figure 10.12 shows the and NMR spectra of poly(ether-imide)/ poly(aryl ether ketone) (PEI/PAEK) obtained from the chemical-shift selective Goldman-Shen experiment with (the righthand side) and without (the lefthand side) detection [108]. The signals from the aliphatic protons of PEI at 2 ppm are resolved from the aromatic protons of PEI and... 

Fig. 10.22. Plots of normalized deviations from the sample-averaged proton polarizations (per spin) for nylon and PBZT protons in nylon/PBZT-40/60. MP refers to the multiple-pulse version of the spin-diffusion experiment (the modified chemical-shift selective Goldman-Shen experiment) PLS indicates the proton lineshape version (the T2-selective Goldman-Shen experiments with C detection). (Reprinted with permission from Ref. [82]. 1990 Huthig Wepf Verlag.)...

Solid state proton line shape experiments on PMP and Goldman-Shen proton spin diffusion experiments on PMP were performed on a Bruker MSL 300. The 900 pulse width was typically 2 is. The Goldman-Shen experiments were performed at a temperature of 350 K with a discrimination time of )ps. 

The slightly modified Goldman-Shen experiment employed herein is designed to detect and analyze carbon-13 NMR signals. In this respect, we rely on chemical structural differences as well as motional differences between the two types of segments to assign the i3C spectrum and provide... 

Figure 4 Schematic rf pulse representation of the slightly modified Goldman-Shen experiment to monitor proton spin diffusion between two domains of dissimilar mobility via high-resolution detection of carbon-13 signals. The dipolar dephasing delay (xi) was fixed at 15 ps, the spin-diffusion mixing period (12) was either 0.01 ps or 10 ms, and the iH-i3C cross-polarization contact time was 100 ps.

Figure 5 High-resolution carbon-13 solid state NMR spectra of the MDI-based polyurethane elastomer from the slightly modified Goldman-Shen experiment.

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