The Preparations And Chromatographic Characterizations Of ND And OVS Composite Monolithic Columns

Composite monolithic column, being a member of monolithic column, has been developing rapidly in recent years because of its unique composite virtues.Two different composite monolithic columns were successfully prepared:Firstly, after being oxidated, chlorinated and esterificated, the modified nanodiamond with allyl-alcohol(ND-A) was prepared. With ND-A as a monomer, ethylene glycol dimethacrylate(EDMA) as cross-linker, 1-dodecanol as porogenic agent and benzoyl peroxide/dimethylacetamide(BPO/DMA) as initiator, the poly(ND-co-EDMA) composite monolithic column was prepared at 35 ?. After being characterized with SEM, BET, TGA, XRD MIP and FTIR, the increase of specific surface area and the tolerance of microstructure to high temperatures with the addition of ND-A were confirmed. The highest swelling of the composite was about 5 % in the swelling test. The influences of different factors on band broadening were measured with the peak parking method. At last, the home-made composite monolithic column was used for the chromatographic separation of small molecules successfully.Secondly, a poly(OVS-co-EDMA) composite monolithic column was prepared with octavinyloctasilasesquioxane(OVS) as a monomer, BPO/DMA as an initiator, EDMA as a cross-linker, 1-dodecanol as a porogenic agent and dimethylbenzene as co-solvent. According to the characterizations of SEM, BET, and swelling test, the improved skeleton, larger specific surface area, and lower swelling of the monolithic column were achieved with the addition of OVS. Moreover, the obtained composite monolithic column was successfully used for small molecules in chromatographic separation.