Tutorials 2025

The word diffusion derives from the Latin word diffundere, which means "to spread out". In the most general case, diffusion is a phenomenon that refers to the net movement of an object driven by a gradient of some magnitude factor. The process has a stochastic nature, and its concept plays an important role in many areas of physics, chemistry, biology, sociology, economics, and finance, constituting a broad field for research. In natural sciences, diffusion is not limited to a given state of matter but can occur in solids, liquids, and gases. It conditions the life processes by determining the transport through membranes, cells eventually, the whole body. In chemical processes, it is often the central rule driving many reactions. In physics, it defines many transport processes for atoms, ions, or molecules. A distinguishing feature of diffusion is that it depends on particle random walk and results in mixing or mass transport without requiring directed bulk motion. The first description of the diffusion phenomena was given by Adolf Fick in 1855. Fick's laws can be used to solve for the diffusion coefficient, D. A diffusion process that obeys Fick's laws is called normal or Fickian diffusion. On the other hand, it is called anomalous diffusion or non-Fickian diffusion if the process does not follow these laws. This tutorial aims to give an overview of the wide range of applications of diffusion NMR and principles of NMR diffusometry methods that allow insight, for example, for accurate molecular size determination, in nanomedicine drug delivery, or separation of complex mixtures.