论文部分内容阅读
The first generation of porous polymer monoliths emerged in the late 1980s and proved to be excellent stationary phase for the separation of large molecules.Their well known advantages include ease of the preparation, robustness, high permeability to flow, mass transfer via convection, and a vast variety of chemistries.However, these monoliths had a small surface area since they lacked the mesopores.This made them quite useful for the separation of large molecules such as synthetic polymers and proteins as well as particles including nanoparticles and viruses.We have recently developed and demonstrated the second generation monoliths using a new two-step approach to the control of porous properties that includes hypercrosslinking reaction.This technique includes the preparation of generic monoliths followed by their solvation and rapid crosslinking.This process enables the preparation of porous polymer monoliths possessing large surface areas of several hundreds m2/g.Traditionally, the surface chemistry of the monoliths is controlled via copolymerization with monomers bearing the desired functionality, chemical modification of preformed monolith, and photografting of pore surface with polymer chains bearing the desired functionalities.Now, we have introduced novel approaches involving nanochemistry.For example, we modify the pore surface within our monoliths with gold nanoparticles affording columns with a specific selectivity enabling separation and/or fishing out thiol-containing compounds.We are also developing processes for the immobilization of nanostructures such as multiwalled carbon nanotubes and functionalized C60 nanoparticles that afford monolithic columns exhibiting high efficiency in the separations of small molecules.