Influence of photo-initiators in the preparation of methacrylate monoliths into poly(ethylene-co-tetrafluoroethylene) tubing for microbore HPLC

In situphotoinitiated fabrication of phosphorylcholine-functionalized polyhedral oligomeric silsesquioxane hybrid monolithic column for mixed-mode capillary electrochromatography

“…The results could be attributed to the increase in the polymerization rate, which would generate much more free radicals and growing agglomerates of polymers and form smaller globules. 44 It was found that the M2 column (at 8 min) showed more uniform pore structures with a higher number of clusters generated from smaller globules, and an average large through-pore of 3 μm size as well (Fig. 2 M2-1).…”

Construction of polymer monolithic columns in polypropylene ink‐pen tubes for separation of proteins by cation‐exchange chromatography

“…Then, the tubes filled with a solution of 5 wt% BP in methanol, formerly sonicated (10 min), and purged with N 2 (10 min), were closed in both ends and irradiated for 20 min under 254 nm at 120 mJ/cm 2 . In all experiments, the tubes were positioned 2.5 cm apart from the UV‐lamps [9,13]. After this first step, the tubes were washed with methanol and dried with N 2 .…”

“…A polymerization mixture containing 30 wt% GMA, 10 wt% EDMA, 35 wt% 1‐propanol, 20 wt% 1,4 butanediol, and 5 wt% H 2 O was prepared in a 2 mL amber vial in the presence of 1.0 wt% DMPAP (concerning the monomers). The mixture was sonicated (10 min), purged with N 2 (10 min), and used to fill the activated PP tubes, which were closed in both ends, vertically positioned 2.5 cm apart from the UV‐lamps, and irradiated for 20 min under 254 nm at 120 mJ/cm 2 [9,13]. Then the columns were flushed with ACN at 500 µL/min using an HPLC pump until a constant pressure.…”

“…While thermal polymerization takes several hours to achieve acceptable reaction conversion, photopolymerization takes only a few minutes [11,12]. Following this strategy, monolithic columns were recently prepared inside the UV‐transparent ETFE [9,13] and FEP [14] tubing. Polypropylene is a cheap plastic material that houses monolithic materials for solid‐phase extraction inside pipette tips [15] and syringe barrels [16].…”

Recent developments and applications of polymer monolithic stationary phases

“…Catalá‐Icardo et al. investigated the effect of the type of photoinitiator and irradiation time on morphology of monolithic columns and resulting chromatographic performance 43 . The initiators they used were azobisisobutyronitrile, benzophenone, 2,2‐dimethoxy‐2‐phenylacetophenone, and 2‐methyl‐4′‐(methylthio)‐2‐morpholinopropiophenone.…”