DOWEX Fine Mesh Spherical Ion Exchange Resins

For the highest levels of selectivity, consistency, and reliability in column separations, there is no better choice than DOWEX* spherical fine mesh ion exchange resins. DOWEX fine mesh resins are produced by selectively controlling the suspension polymerization technology we use to produce our standard 16–50 mesh industrial resins. The resulting resins consist of whole, spherical beads that provide excellent kinetic and packing properties in chromatographic separations...without the problems associated with ground or granular resins.

Dow offers a wide range of fine mesh resins for use in fine chemical and pharmaceutical column separations. Anion and cation resins with mesh sizes including 50–100, 100–200, and 200–400 are available. Cross-linkages (as measured by percent divinylbenzene content) include 2, 4, and 8. This broad product line permits selection of a resin offering the optimum levels of permeability, water retention capacity, and total capacity for your particular application.

Dow's range of resin options not only enhances your ability to optimize laboratory separations but also simplifies the adjustments that are often necessary during process scale-ups. This can help ensure that your success in the lab translates into success in pilot-scale as well as full-scale plant operations.

DOWEX fine mesh resins are durable, pH tolerant, clean, and predictable separations media that perform consistently and reliably in fine chemical and pharmaceutical column separations.

Strong, insoluble structure—DOWEX fine mesh resins are based on a microporous copolymer of styrene and divinylbenzene (DVB) that results in maximum resistance to oxidation, reduction, mechanical wear, and breakage. What's more, this structure is also insoluble in common solvents. Figure 1 depicts the synthesis of DOWEX resins.

Low in fines—DOWEX fine mesh resins are produced through direct synthetic manufacture. This results in whole, spherical resin beads that are cleaner and perform more reliably and consistently than ground resins. Ground resins consist of irregularshaped particles and contain "fines" or very fine particles. Fines are a particular source of processing difficulties. They produce dust when dry resins are handled. They plug frits and filters when the resin is used as chromatographic media or as a filtering aid. They extend settling times in batch processing applications. And they contribute to resin attrition due to physical losses.

Tight control of particle size and permeability—By controlling the suspension polymerization process, the particle size of DOWEX fine mesh resins is tightly regulated. The percentage of DVB used in the process is also controlled to determine cross-linkage (or permeability) of the resins. These factors result in a range of products with specific, dependable performance characteristics.