title: Polymerisation and surface modification of methacrylate monoliths in polyimide channels and polyimide coated capillaries using 660 nm light emitting diodes.
abstract: An investigation into the preparation of monolithic separation media utilising a cyanine dye sensitiser/triphenylbutylborate/N-methoxy-4-phenylpyridinium tetrafluoroborate initiating system activated by 660 nm light emitting diodes is reported. The work demonstrates multiple uses of red-light initiated polymerisation in the preparation of monolithic stationary phases within polyimide and polyimide coated channels and the modification of monolithic materials with molecules which absorb strongly in the UV region. This initiator complex was used to synthesise poly(butyl methacrylate-co-ethylene dimethacrylate) and poly(methyl methacrylate-co-ethylene dimethacrylate) monolithic stationary phases in polyimide coated fused silica capillaries of varying internal diameters, as well as within polyimide micro-fluidic chips. The repeatability of the preparation procedure and resultant monolithic structure was demonstrated with a batch of poly(butyl methacrylate-co-ethylene dimethacrylate) monoliths in 100 μm i.d. polyimide coated fused silica capillary, which were applied to the separation of a model protein mixture (ribonuclease A, cytochrome C, myoglobin and ovalbumin). Taking an average from 12 chromatograms originating from each batch, the maximum relative standard deviation of the retention factor (k) for the protein separations was recorded as 0.53%, the maximum variance for the selectivity factor (α) was 0.40% while the maximum relative standard deviation in peak resolution was 8.72%. All maxima were recorded for the Ribonuclease A/Cytochrome C peaks. Scanning electron microscopy confirmed the success of experiments in which poly(butyl methacrylate-co-ethylene dimethacrylate) monoliths were prepared using the same initiation approach in capillary and micro-fluidic chips, respectively. The initiating system was also applied to the photo-initiated grafting of a chromophoric monomer onto poly(butyl methacrylate-co-ethylene dimethacrylate) monoliths within poly(tetrafluoroethylene) coated fused silica capillaries.
authors.affiliation: Irish Separation Science Cluster, National Centre for Sensor Research, Dublin City University, Glasnevin, Dublin 9, Ireland.
authors.forename: Zarah
authors.initials: Z
authors.lastname: Walsh
authors.forename: Pavel A
authors.initials: PA
authors.lastname: Levkin
authors.forename: Silvija
authors.initials: S
authors.lastname: Abele
authors.forename: Silvia
authors.initials: S
authors.lastname: Scarmagnani
authors.forename: Dominik
authors.initials: D
authors.lastname: Heger
authors.forename: Petr
authors.initials: P
authors.lastname: Klán
authors.forename: Dermot
authors.initials: D
authors.lastname: Diamond
authors.forename: Brett
authors.initials: B
authors.lastname: Paull
authors.forename: Frantisek
authors.initials: F
authors.lastname: Svec
authors.forename: Mirek
authors.initials: M
authors.lastname: Macka
mesh_terms: D001578:Benzopyrans / Q000737:chemistry; D007094:Imides / Q000737:chemistry*; D007211:Indoles / Q000737:chemistry; D008027:Light; D008689:Methacrylates / Q000737:chemistry*; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation* / Q000379:methods; D008855:Microscopy, Electron, Scanning; D009574:Nitro Compounds / Q000737:chemistry; D010316:Particle Size; D055668:Photochemical Processes; D058105:Polymerization; D011506:Proteins / Q000737:chemistry / Q000302:isolation & purification; D015203:Reproducibility of Results; D013053:Spectrophotometry / Q000379:methods; D013499:Surface Properties
chemical_list: D001578:Benzopyrans; D007094:Imides; D007211:Indoles; D008689:Methacrylates; D009574:Nitro Compounds; D011506:Proteins; C516546:poly(butyl methacrylate-co-ethylene dimethacrylate); C088184:spiropyran