Gigaporous polymer beads have very large macropores (dpore/dparticle> 0.01). For particle sizes of 10 micron and 50 micron, the pores sizes are larger than 1000 and 5000 angstroms, respectively. In collaboration with Prof. G. Ma at IPE, we have developed two new spherical polymer bead systems for preparative- and large-scale liquid chromatography and other applications. Our polymer synthesis methods are completely different from that used in making the POROS perfusion chromatography media. Instead of making submicron porous spheres before assembling them into large beads, our polymers are synthesized in a single step. The porous microspheres are integral particles with very good physical strength. Nominal particle sizes can be anywhere between 10 and 100 micron with densities slightly above that for water. Particles for various forms of liquid chromatography (size-exclusion / gel filtration, affinity, ion-exchange, reversed phase, etc.) can be developed. Monolithic media are also feasible. In addition to chromatographic applications, these gigaporous polymer beads are excellent microcarriers for fungal and animal cell cultures providing a huge amount of internal pore surfaces for relatively large cells to attach. The pore surfaces can be made hydrophilic or hydrophobic depending on actual applications. Additional applications can be found in drug delivery and catalysis.
Advantages:
1. The new polymer synthesis method provides independent controls on diffusion-pore size and gigaporous through-pore size during synthesis. The smaller diffusion-pores (100 - 500 Angstroms or higher) provide the needed surface area while the much larger (up to 1 micron or higher) through-pores allow better accessibility to the diffusion-pores.
2. Large through-pores permit convective flow. Convective flow in the through-pores results in increased mass transfer rates that result in sharper peaks in liquid chromatography. With a greatly enhanced flow rate (up to 40 folds), rigid gigaporous particles make the chromatographic column scale-up in the axial direction possible. Longer columns provide superior resolution to that offered by short pancake-like columns. With the new technology, column scale-up will no longer be limited to diameter enlargement.
3. The gigaporous particles offer greatly improved availability of binding sites/ligands due to the large pore sizes resulting in increased loading capacity per unit polymer weight.
4. The highly cross-linked polymer is stable in acidic and basic pH conditions with a wide operating pH range. (Traditional silica beads are stable for acidic pH only.)
5. The Rigid beads are better than the existing gel beads that suffer from severe swelling.
6. The gigapores can be made large enough to handle extremely large DNA molecules for chromatographic separations.
Samples for preliminary evaluations are available upon request. Currently, polystyrene and poly(glycidyl methacrylate) (aka poly GMA) polymers are available. If you are interested in the gigaporous media, we can send you a research proposal. After that, your company can send a purchase order to Ohio University's Office of Research and Sponsored Programs as a research grant. With the grant, we can perform experiments to develop the new gigaporous media for your specific applications.
If interested, please feel free to contact:
Prof. Tingyue Gu, Ph.D.
Department of Chemical Engineering
Stocker 178, Ohio University
Athens, Ohio 45701
Phone: 740-593-1499, Fax: 413-215-6702
http://www.ent.ohiou.edu/~guting
