At the atomic level, a glass of water and a spoonful of crystalline salt couldn't look more different. Water atoms move around freely and randomly, while salt crystals are locked in place in a lattice. But some new materials, recently investigated by researchers at the U.S. Department of Energy's (DOE) Argonne National Laboratory, show an intriguing propensity to sometimes behave like water and sometimes like salt, giving them interesting transport properties and holding potential promise for applications like mixing and delivery in the pharmaceutical industry.