Temperature-Dependent Magnetic Resonance Relaxation Behaviors in Porous Materials

We observe divergent temperature-dependent magnetic resonance relaxation behaviors across various brine-saturated porous materials. The paramagnetic and diamagnetic nature of the samples underlies these divergent behaviors. The temperature-dependent trends of the longitudinal T₁ and transverse T₂ relaxation times are systematically explained via distinct relaxation-diffusion regimes of Brownstein-Tarr theory. Water diffusivity is a key determinant of the behavior. While systematic temperature-dependent relaxation trends were observed with the majority of the samples, a minority showed temperature independence. This was attributed to the transition of relaxation behaviors between distinct relaxation-diffusion regimes. The temperature dependence observed reinforces the notion that Brownstein-Tarr theory describes the full gamut of relaxation behaviors in fluid saturated porous media.