Analytical Instrument Documents

The ROSY (Relaxation Ordered SpectroscopY) is a method in which the ¹³C CPMAS spectrum of a mixture is classified by a longitudinal relaxation time of ¹H, and the ¹³C CPMAS spectrum is displayed separately for each substance. In solution NMR, each peak in the ¹H spectrum has its own longitudinal relaxation time. In solid-state NMR, however, spin diffusion occurs due to the dipolor interaction between ¹H, and all ¹H have the same longitudinal relaxation in the domain within a certain distance. The ¹³C spectrum can be separated for each domain by using this difference in relaxation time of ¹H. The longitudinal relaxation time (T₁^H) obtained by the saturation recovery method as shown in Fig.1a is usually used to separate the ¹³C spectrum of the mixture. The size of the domain that can be separated by this method is about 100 nm. To separate domains smaller than this, a measurement using the relaxation time at rotational flame (T_1ρ^H) obtained by the spinlock method as shown in Fig.1b is effective. The domain size that can be separated by T_1ρ^H is about several nm, and it is possible to determine the phase separation structure of block copolymers and the molecular compatibility.