Gel permeation chromatography on porous poly(ethylene glycol methacrylate)

This review summarizes the preparation and application of chromatographic separation media based on methacrylate monomers with a major focus on highly crosslinked macroporous beads prepared from 2-hydroxyethyl methacrylate and glycidyl methacrylate, respectively. The effects of process variables such as composition of the polymerization mixture that includes monomers, porogenic solvents, and free radical initiator, suspension stabilizer, reaction temperature, and stirring are detailed for both classical and templated suspension polymerization. In addition, specific features of the preparation of monodisperse beads are also discussed. The performance of methacrylate-based separation media is demonstrated on numerous separations in a variety of chromatographic modes.

Section: Degree Of Crosslinkingmentioning

confidence: 98%

Methacrylate‐based chromatographic media

Beneš

Horák

Švec³

2005

“…For example, highly swollen polymer gel was prepared by free-radical polymerization of an aqueous solution of 2-hydroxyethyl methacrylate with 0.2% ethylene dimethacrylate (crosslinking monomer) [40]. This single piece of gel was inserted into a 220623.5 mm ID glass tube, and this column was used for size-exclusion chromatography.…”

Section: Monolithic Columnsmentioning

confidence: 99%

Organic polymer monoliths as stationary phases for capillary HPLC

Švec¹

2004

183

111

Modern rigid porous polymer monoliths were conceived as a new class of stationary phases in classical columns in the early 1990s and later extended to the capillary format. These monolithic materials are typically prepared using a simple molding process carried out within the confines of the capillary. Polymerization of a mixture comprising monomers, initiator, and porogenic solvent affords macroporous materials with large through-pores that enable applications in a rapid flow-through mode. Since all the mobile phase must flow through the monolith, convection considerably accelerates mass transport within the monolithic separation medium and improves the separations. As a result, monolithic columns perform well even at very high flow rates. Various mechanisms including thermally and UV initiated free radical polymerization as well as ring opening metathesis copolymerizations were demonstrated for the preparation of monolithic capillary columns. The versatility of these preparation techniques was demonstrated by their use with hydrophobic (styrene, divinylbenzene, butyl methacrylate, ethylene dimethacrylate), hydrophilic (2-hydroxyethyl methacrylate, methacrylamide, methylenebisacrylamide), ionizable (vinylsulfonic acid, 2-acrylamido-2-methyl-propanesulfonic acid), and tailor-made (norborn-2-ene, 1,4,4a,5,8,8a-hexahydro-1,4,5,8-exo,endo-dimethanonaphthalene) monomers. Variation of polymerization conditions enables control of the porous properties of the monolith over a broad range and mediates the hydrodynamic properties of the monolithic columns. The applications of polymer-based monolithic capillary columns are demonstrated for numerous separations in the microHPLC mode.

“…The first attempts to make "single-piece" separation media date back to the late 1960s and early 1970s. For example, highly swollen monolithic polymer gel was prepared by free-radical polymerization of an aqueous solution of 2-hydroxyethyl methacrylate with 0.2% ethylene dimethacrylate (crosslinking monomer), inserted into a glass tube, and used for size-exclusion chromatography in 1967 [1]. Unfortunately, the effectiveness of fractionation was rather low.…”

Section: Introductionmentioning

confidence: 99%

Preparation and HPLC applications of rigid macroporous organic polymer monoliths

Švec

2004

226

134

Rigid porous polymer monoliths are a new class of materials that emerged in the early 1990s. These monolithic materials are typically prepared using a simple molding process carried out within the confines of a closed mold. For example, polymerization of a mixture comprising monomers, free-radical initiator, and porogenic solvent affords macroporous materials with large through-pores that enable applications in a rapid flow-through mode. The versatility of the preparation technique is demonstrated by its use with hydrophobic, hydrophilic, ionizable, and zwitterionic monomers. Several system variables can be used to control the porous properties of the monolith over a broad range and to mediate the hydrodynamic properties of the monolithic devices. A variety of methods such as direct copolymerization of functional monomers, chemical modification of reactive groups, and grafting of pore surface with selected polymer chains is available for the control of surface chemistry. Since all the mobile phase must flow through the monolith, the convection considerably accelerates mass transport within the molded material, and the monolithic devices perform well, even at very high flow rates. The applications of polymeric monolithic materials are demonstrated mostly on the separations in the HPLC mode, although CEC, gas chromatography, enzyme immobilization, molecular recognition, advanced detection systems, and microfluidic devices are also mentioned.