For nearly half a century now, NMR has been well appreciated as a powerful spectroscopic tool in, among others, chemistry, physics and biomedical science. Its applications are numerous and wide-ranging. The development of Magnetic Resonance Imaging (MRI), for instance, has opened new areas of NMR applications, most of them being specific to the medical world. Nowadays, a wide variety of NMR techniques are available for research purposes. One of these is field-cycling NMR relaxation spectroscopy, which enables one to measure spin-lattice relaxation times over a broad range of magnetic field strengths. The study of these relaxation times than provides details about molecular motions and spin interactions. One of the topics under study in our unit is the spin-lattice relaxation time of water nuclei in dilute aqueous suspensions of colloidal silica particles. The aim of this research is double. First of all, the water relaxation mechanisms are experimentally explored in a model system, composed of simple spherical macromolecules. And hopefully, the information thus obtained will be helpful to establish the relaxation pathways in more complex heterogeneous systems, such as protein and polymer solutions or even in biological tissues and fluids. In addition, the surface chemistry and the water interactions at an oxide- interface are probed through this study of the solvent relaxation times. The appreciation of the physical chemistry of oxide interfaces, especially in an aqueous environment, and the reactions controlled by them is a prerequisite for understanding many of the important processes of natural systems. Here we evolve in a field which has possible applications in, e.g., catalysis, soil and mineral chemistry. In parallel, other members in our group apply MRI imaging techniques in order to determine, in vivo, the structure of human bone. It is their aim to develop techniques which must be patient-friendly but are nonetheless capable of predicting bone strength with sufficient accuracy so that they can be helpful in the diagnosis of osteoporosis.