Preparation, characterization and use of mixed-mode polymeric monolithic capillary columns exploring interactions between gold nanoparticles and thiols

Abstract

With this project we aim to learn the technology of synthesis of polymeric capillary monoliths for applications in liquid chromatography. These columns are a highly porous continuous medium of separation that provides high permeability and high separation efficiency, allowing analyzes to be made at high flow rate and low pressure. Unlike packed columns, the commercial availability of monolithic columns is limited to pure silica for normal phase chromatography and silica modified with C8 or C18 groups for reversed phase chromatography. Several research groups around the world are working in the field of monolithic materials. Most of these efforts are dedicated to the development of new stationary phases for using in separation techniques applied to complex biological matrices. Additionally, microfluidic reactors and solid phase extraction devices have also been benefited from the physical and chemical properties of monolithic materials. This kind of research area is not yet well developed in Brazil. The present project aims the preparation of mixed mode polymeric monolithic columns, exploiting the high affinity between gold nanoparticles and thiol-containing substances. A generic monolith will be synthesized from a mixture of glycidyl methacrylate (functional monomer) and ethylene glycol dimethacrylate (cross-linking monomer) in a mixture of cyclohexanol-dodecanol (porogenic solvents) and azobisisobutyronitrile (radical initiator). This generic monolith will be modified by reaction with cysteamine or cystamine, followed by the addition of gold nanoparticles, which will bind to the thiol groups. This structure will be treated with a mixture of different thiols in order to incorporate functional groups of different chemical nature (C8, C18, NH2, SO3-, OH, etc), producing a chromatographic column with mixed modes of separation. (AU)