Poly(ethyleneimine) cross-linked with glutaraldehyde has been coated on partially hydrolyzed poly(acrylonitrile) (textile grade), used in fiber as well as fabric form, by a copper-mediated gel-coating process. For uranium sorption from aqueous solutions at low substrate concentrations (less than or equal to1 mmol/L), the gel-coated fiber or fabric, containing 15% resin (w/w on a dry basis), exhibits an order of magnitude higher sorption capacity and 2 orders of magnitude higher initial rate of sorption, as compared to conventional bead-form anionic resin Dowex 21K. For example, in a 1 mM solution Of UO2SO4 at pH 4.0, the sorption capacities of the gel-coated fiber and Dowex 21K resin beads are respectively 106 and 12 mg of U/g of dry sorbent, while the initial rates of sorption are 3.5 and 0.02 mg of U/(g of dry sorbent)(s), respectively. With the sorption on the gel-coated fiber being by both ion exchange and chelation, it shows a significantly greater salt (NaCl) tolerance than Dowex 21K on which the sorption takes place only by ion exchange. Following fast stripping with dilute mineral acid, the gel-coated fiber is regenerated by a simple wash with dilute alkali to its original capacity. The sorption rate data on the fiber, in the initial stage, fit to a shell-core model equation derived for a cylindrical-shaped sorbent of a very large length/diameter ratio.