Single-shot measurement of solids and liquids T values by a small-angle flip-flop pulse sequence.

We propose the small-angle flip-flop (SAFF) pulse sequence as an alternative procedure for the rapid measurement of the H spin-lattice relaxation time in the laboratory frame (T ) of solid and liquid substances, in a time-domain NMR experiment. Based on the original flip-flop pulse sequence, this technique allows the fast estimation of T values of samples that require minutes to hours of acquisition time if traditional pulse sequences are employed. We have applied SAFF to different substances, with T ranging from microseconds up to seconds, including natural clays, polymers, and organic and inorganic solvents.

Data on tensile tests and NMR measurements of poly(vinilidene fluoride) before and after stress relaxation.

Poly(vinilidene fluoride) was characterized before and after stress relaxation by tensile tests and time-domain nuclear magnetic resonance (TD-NMR). Tensile tests were performed to provide mechanical properties, focused on the data of elastic modulus for this matter. The TD-NMR technique was used to calculate the fraction of crystalline, constrained amorphous and free amorphous phase, and the transversal relaxation time of each of these phases.

Proton NMR relaxometry as probe of gelatinization, plasticization and montmorillonite-loading effects on starch-based materials.

The effects of granule disruption, the addition of glycerol and montmorillonite on the granule structure of corn starch were investigated by proton NMR relaxation, through the T, T and T relaxation times. Films containing 0%, 1%, 5% and 7%(w/w) of clay were prepared by solution casting and the relaxometry data were compared with those gleaned from WAXD, TGA and SEM techniques. Starch gelatinization without glycerol or clay results in an amorphous and rigid film having a dipole coupling higher than that observed for the granule.