Seminars

Physical Reconstruction and Morphological Analysis of Granular and Monolithic Materials : From Metric Properties to Structural Descriptors of Diffusion and Hydrodynamic Dispersion

The discovery of the morphology-transport relationships for chromatographic media (packed and monolithic beds, confined pillar structures) belongs to the major challenges in separation science, because it requires the 3D physical reconstruction and/or computer-generation of the media followed by 3D mass transport simulations to collect meaningful data for a detailed analysis of morphological and transport properties. Although expensive computationally as well as experimentally, this approach is the only direct as well as the most realistic way to understand and optimize current and future chromatographic supports.
After a brief summary of the challenges involved, I will report our latest progress regarding the following issues : (1) The systematic study of how individual parameters, such as the particle size distribution, particle porosity, the bed porosity, and the confinement, affect the morphology of computer-generated packed beds [1–3]. (2) The physical reconstruction of real packed and monolithic beds to collect information on how experimental parameters of the preparation process influence the morphology of a chromatographic medium. Up to now, the preparation process is hardly understood due to the previous lack of the requisite morphological data [4–7]. (3) 3D mass transport simulations performed on a dedicated high-performance supercomputing platform to quantify the band broadening processes from the pore scale up to the column scale in reconstructed and computer-generated chromatographic media [8–14]. (4) The analysis of computer-generated and/or physically reconstructed packed and monolithic beds with statistical methods to derive appropriate and unique structural descriptors for mass transport (diffusion, dispersion) [4–9], which have great potential for refining the existing theoretical framework.

[1] S. Khirevich, A. Höltzel, D. Hlushkou, U. Tallarek, Anal. Chem. 79 (2007) 9340.
[2] S. Khirevich, A. Höltzel, S. Ehlert, A. Seidel-Morgenstern, U. Tallarek Anal. Chem. 81 (2009) 4937.
[3] A. Daneyko, A. Höltzel, S. Khirevich, U. Tallarek, Anal. Chem. 83 (2011) 3903.
[4] S. Bruns, U. Tallarek, J. Chromatogr. A 1218 (2011) 1849.
[5] S. Bruns, T. Müllner, M. Kollmann, J. Schachtner, A. Höltzel, U. Tallarek, Anal. Chem. 82 (2010) 6569.
[6] S. Bruns, T. Hara, B. M. Smarsly, U. Tallarek, J. Chromatogr. A 1218 (2011) 5187.
[7] S. Bruns, J. P. Grinias, L. E. Blue, J. W. Jorgenson, U. Tallarek, Anal. Chem. 84 (2012) in press (doi : 10.1021/ac300326k)
[8] S. Khirevich, A. Daneyko, A. Höltzel, A. Seidel-Morgenstern, U. Tallarek, J. Chromatogr. A 1217 (2010) 4713.
[9] S. Khirevich, A. Höltzel, A. Daneyko, A. Seidel-Morgenstern, U. Tallarek, J. Chromatogr. A 1218 (2011) 6489.
[10] S. Khirevich, A. Höltzel, A. Seidel-Morgenstern, U. Tallarek, Anal. Chem. 81 (2009) 7057.
[11] D. Hlushkou, S. Bruns, U. Tallarek, J. Chromatogr. A 1217 (2010) 3674.
[12] D. Hlushkou, S. Bruns, A. Höltzel, U. Tallarek, Anal. Chem. 82 (2010) 7150.
[13] D. Hlushkou, S. Bruns, A. Seidel-Morgenstern, U. Tallarek, J. Sep. Sci. 34 (2011) 2026.
[14] A. Daneyko, S. Khirevich, A. Höltzel, A. Seidel-Morgenstern, U. Tallarek, J. Chromatogr. A 1218 (2011) 8231.