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作者 Langford, John F., Jr
書名 Effects of adsorbent structure and adsorption on transport phenomena in ion-exchange chromatography
說明 250 p
附註 Source: Dissertation Abstracts International, Volume: 67-12, Section: B, page: 7214
Adviser: Abraham M. Lenhoff
Thesis (Ph.D.)--University of Delaware, 2007
Ion-exchange chromatography is widely used in downstream bioprocessing due to its ability to separate a wide range of biomolecules with a high degree of precision. Predicted expansion of the pharmaceutical industry will force process and adsorbent designers to swiftly adapt their techniques to increase the speed, cost efficiency and resolution of the purification process. While most adsorbent manufacture and process selection is done with extensive empirical screening, the goal of this work is to provide tools and techniques that will aid in adsorbent manufacture and in process design. This is done by determining the mechanisms by which adsorbent pore structure and adsorption behavior affect intraparticle transport
The first portion of the work focuses on the role of the adsorbent pore structure in dictating diffusive transport. A network model was developed that uses detailed pore structure information for three different adsorbents to predict intraparticle diffusivities of molecules of different sizes. Network modeling results were compared to both Brownian dynamics simulations and experimental diffusivity results. The results demonstrate the relative effects of pore size and connectivity on transport. Comparison of the two modeling techniques with experimental data indicates that the network modeling and Brownian dynamics predictions agree quite well, but successfully predict the behavior of only one of three of the adsorbents studied. The two materials for which poorer agreement was obtained are both on methacrylate base matrices that are known to display significant variability between and within lots
The second portion of the work focuses on the combined adsorption and diffusion behavior of proteins in ion-exchange adsorbents. Past work indicated that enhancements in transport were observed under solution conditions that coincide with a transition from pore diffusion to homogeneous diffusion. This work verifies these findings on multiple protein-adsorbent systems and shows that the underlying driving force for this phenomenon is related to isocratic retention. A correlation is presented that allows prediction of the solution conditions at which the enhanced transport will be realized. This provides a method for process designers to predict ideal operating conditions and reduces the need for extensive screening experiments
School code: 0060
DDC
Host Item Dissertation Abstracts International 67-12B
主題 Engineering, Chemical
0542
Alt Author University of Delaware
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