Pulsed field gradient NMR spectroscopy

SJ Gibbs, EN Lightfoot, TW Root. Protein diffusion in porous gel filtration chromatography media studied by pulsed field gradient NMR spectroscopy. J Phys Chem 96 7458-7462, 1992. 

Mesoporous structures are commonly characterized with diffraction, electron microscopy methods [14], and gas sorption techniques. The ensemble diffusion behavior of small molecules has been examined with pulsed-field gradient NMR spectroscopy [15] and neutron scattering [16]. Here, we are interested in techniques which give a more direct access to the real structure of the mesoporous host and to the dynamics on a single-molecule basis, and thus reveal structural and dynamic features which are not obscured by ensemble or statistical averaging as in conventional techniques. 

Polymer electrolyte membrane Polymer electrolyte membrane fuel cell Pulse field gradient NMR spectroscopy Perfluorosulfonic acid ionomer... 

The concentration dependence of the and NMR chemical shifts of tetramethyldisiloxanediol in CDCI3 has been investigated. The dynamics and structure of polydimethylsiloxane emulsions have been studied by pulsed field gradient NMR spectroscopy.A H- C- Si triple resonance three-dimensional NMR study of poly(dimethylsiloxane) has been reported. Orientation of compressed siloxane elastomers has been investigated using NMR spectroscopy. Transverse relaxation measurements have been used... 

Pulse Field Gradient NMR spectroscopy can be applied to investigate self-diffusion of molecules in solution, through membranes, and through zeolites. PFG NMR is a direct method to measure the mean square distance which is traveled by a tracer during a time period At. Under the conditions of free-isotropic diffusion in three dimensions (dilute solutions), the replacement is related to the self-diffusion coefficient by Equation 23. 

The coagulation of hydrolysed aluminium salts has been studied using A1 NMR spectroscopy. The hydrolysis of mixed solutions of Al , Ga ", Ln , and Zr" has been studied by Al and Ga NMR spectroscopy. A C and A1 NMR study of the interaction between Al and tiron, salicylic acid, and phthaUc add has been reported. B, A1, and Si NMR studies of the temperature dependent structural changes in borate, borosilicate, and boro-aluminate Uquids have been reported. The interaction of aluminosilicates by HF has been investigated. Aluminium in polysilicic acid has been speciated using A1 NMR spectroscopy. C, A1 and P NMR spectroscopy has been used to study the formation of Al-NTA-phosphate complexes. The selfdiffusion coefficients of the ATP complex of Al have been studied by H and P pulsed-field gradient NMR spectroscopy. H NMR spectroscopy has been used to study the interaction of Al with phosphatidylcholine vesicles. ... 

NMR relaxation has been used to study water confined in porous silica. The quantification of microporosity has been achieved by Ti measurements of water. The filling processes of water and cyclohexane in porous silica have been investigated using NMR spectroscopy. NMR spectroscopy has been used to validate NMR logs from deeply buried reservoir sandstones. " Fluid saturation has been determined by pulsed field gradient NMR spectroscopy. NMR spectroscopy has been used to study fluids in reservoir rocks. ... 

C NMR spectra of CH4 in an AIPO4-II molecular sieve have revealed exchange effects between adsorbed and nonadsorbed methane gas. The diffusion of a mixture of methane and xenon in the zeoHte siUcahte has been studied by pulsed field gradient NMR spectroscopy. In situ H MAS NMR studies of the H/D exchange of deuterated propane adsorbed on H-ZSM-5 have been reported. C MAS NMR spectroscopy has been used to study the initial stages of propane activation over H-ZSM-5, and sorption properties of hnear alkanes in ferrierite. Protonated sites on sulfate-promoted zirconium oxide catalysts have been studied using H NMR spectroscopy. NMR relaxation and self-diffusion of pentane, neopentane, dodecane, benzene, cyclohexane, and... 

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