Colloidal fibers and devices including colloidal fibers for the purification of water are provided. The fibers include colloidal particles having average diameters from 10 to 1000 nm that include a sulfone polymer. The length of the fibers is at least three times their average cross-sectional width of 35 to 400 .mu.m. The fibers may be made from a solution including the sulfone polymer and a solvent that is mixed with water. The fibers may remove organic matter from water and be regenerated with an alkali solution.