Ronald P. Rohrbach

Properties and applications of externally impregnated shaped fibers

Abstract Polymeric fibers have been produced in an array of geometric cross-sections, all of which possess deep channels along the length of the fiber. These shaped fibers have been made in many different formats including wovens, nonwovens, and parallel arrays. A number of polymeric materials are suitable to retain these nonround cross-sections during spinning; they include polyolefins, polyesters, and polyamides. Specific cross-sections have been observed to capture and tenaciously retain high levels of both liquids and finely divided solids within the channels of the fibers. The liquids are held through capillary forces, while the solids are mechanically entrapped within the channels and do not require adhesives to bond. Their retention is sufficient to allow these impregnated fibers to be used in high-flow applications without experiencing loss of the reagents. Exploiting this property, one can use this type of fiber to support a host of reagents in a practical format for various applications.

Hydrometallurgical Application of a Novel Porous Resin

The technology to manufacture rigid, highly porous materials of very low density that are suitable for use in a wide range of industrial applications has recently been developed in this laboratory. These materials, derived from naturally occurring polymers, have many useful physical characteristics including very large pore volume, pore size distribution in a useful range, and high surface area. These characteristicsw, hen combinedw ith their robust mechanicals trength, make them potentially useful as support matrices for various complexing agents. One demonstrated application of this material is as a polymeric carrierfo r selective liquid metal extractants in hydrometallurgicalp rocesses. We have successfully impregnated our porous matrix with several selective metal extractants, and demonstrated retention of the basic metal binding properties of the immobilized agent. Results of bench scale pilot studies using a copper selective impregnated resin indicate excellent capacity, and good selectivity and extraction/elution kinetics.