Monolithic Sorbents Research Articles

Preparative Monolithic Silica Sorbents (PrepRODs™) and Their Use in Preparative Liquid Chromatography

The use of monolithic silica sorbents for the isolation of substances by preparative liquid chromatography is demonstrated. Preparative liquid chromatography is recognized as a valuable technique for the isolation and purification of substances in the pharmaceutical and fine chemicals industry. The system technology has meanwhile reached a high standard, and the greatest future improvements are expected to arise from new and improved adsorbents. Monolithic silica sorbents offer some unique features for preparative liquid chromatography. They exhibit high efficiencies even at high flow rates due to their fast convective mass transfer and can therefore be used at very high mobile phase velocities, leading to high productivity and hence to maximum process economy. The benefits of this new type of adsorbent are illustrated for an example in batch-chromatographic mode and an example using the continuous simulated moving bed (SMB) technology.

“Molded” Macroporous Poly(glycidyl methacrylate-co-trimethylolpropane trimethacrylate) Materials with Fine Controlled Porous Properties: Preparation of Monoliths Using Photoinitiated Polymerization

A model system has been developed for in situ photopolymerization of glycidyl methacrylate and trimethylolpropane trimethacrylate, leading to macroporous monolithic sorbents. This model system allows the preparation of continuous porous objects intended for applications such as detection, separation, and catalysis. The ease of the preparation, the short time needed for reaction, and the possibility of running the reaction at a low temperature are some of the main advantages of the photoinitiated in situ polymerization compared to a thermally initiated polymerization. Important system variables acting upon the porous properties and flow characteristics of the monoliths have been investigated in an experimental 23 full factorial design. The porous properties of the monoliths are a direct consequence of the quality of the porogenic solvent, as well as the percentage of cross-linking monomer and the ratio between the monomer and porogen phases. The presence of interactive effects between these reaction condit...