Structure analysis methods relaxation time

Another possible solution to the problem of analyzing multiple-layered membrane composites is a newly developed method using NMR spin-lattice relaxation measurements (Glaves 1989). In this method, which allows a wide range of pore sizes to be studied (from less than 1 nm to greater than 10 microns), the moisture content of the composite membrane is controlled so that the fine pores in the membrane film of a two-layered composite are saturated with water, but only a small quantity of adsorbed water is present in the large pores of the support. It has been found that the spin-lattice relaxation decay time of a fluid (such as water) in a pore is shorter than that for the same fluid in the bulk. From the relaxation data the pore volume distribution can be calculated. Thus, the NMR spin-lattice relaxation data of a properly prepared membrane composite sample can be used to derive the pore size distribution that conventional pore structure analysis techniques... 

The spin-lattice relaxation times of essentially all the protons in vindoline, measured by a Fourier transform method, show values reflecting the degree of steric interaction with other protons. (276) A wealth of coupling constant data has been made available by first order analysis of the 300 MHz NMR spectrum of vindolinine [458]. (277) H NMR shifts for the metabolite of vindoline [459] (278) are shown on the structure. 

Non-selective proton spin-lattice relaxation times for several furanoid systems have been measured. Since epimers give significantly different values the method is of value for structural analysis. Methyl tetrofuranosides have been studied... 

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