SUPERFICIALLY POROUS MATERIALS COMPRISING A COATED CORE HAVING NARROW PARTICLE SIZE DISTRIBUTION; PROCESS FOR THE PREPARATION THEREOF; AND USE THEREOF FOR CHROMATOGRAPHIC SEPARATIONS

The present invention provides novel chromatographic materials, e.g., for chromatographic separations, processes for their preparation and separations devices containing the chromatographic materials. The chromatographic materials of the invention have controlled porosity and comprise a chromatographic core material and one or more layers of chromatographic surface materials which each independently provide an average pore diameter, an average pore volume, or a specific surface area such that the combined layers form a chromatographic material having a predetermined or desired pattern of porosity from the core material to the outermost surface. The materials are useful for HPLC separations, normal-phase separations, reversed-phase separations, chiral separations, HILIC separations, SFC separations, affinity separations, perfusive separations, partially perfusive separations, and SEC separations.