A collaboration between Prof. Omar Saleh and Prof. Phil Pincus reveals that adding salt to water forms a protective jacket of ions around dissolved charged polymers.   Experiments  by Sarah Innes-Gold, a graduate student in Materials, show this jacket controls the shape of the polymer, and computer simulations reveal the spatial distribution of ions around the polymer.  The results were found using measurements of a charged biopolymer, hyaluronic acid, common to pharmaceutical and cosmetic products, but the team predicts a similar jacket will form around other biologically-important species, such as RNA and proteins.