title: Real-time monitoring of the progress of polymerization reactions directly on surfaces at open atmosphere by ambient mass spectrometry.
abstract: The progress of an on-surface polymerization process involving alkyl and perfluoroalkyl silanes and siloxanes was monitored in real-time via easy ambient sonic spray ionization mass spectrometry (EASI-MS). When sprayed on surfaces, the organosilicon compounds present in commercially available nanofilm products (NFPs) react by condensation to form a polymeric coating. A NFP for coating of floor materials (NFP-1) and a second NFP for coating tiles and ceramics (NFP-2) were applied to glass, filter paper or cotton surfaces and the progress of the polymerization was monitored by slowly scanning the surface. Via EASI(+)-MS monitoring, significant changes in the composition of hydrolysates and condensates of 1H,1H,2H,2H-perfluorooctyl triisopropoxysilane (NFP-1) and hexadecyl triethoxysilane (NFP-2) were observed over time. The abundances of the hydrolyzed species decreased compared with those of the non-hydrolysed species for both NFP-1 and NFP-2 and the heavier oligomers became relatively more abundant over a period of 15-20 min. A similar tendency favouring the heavier oligomers was observed via EASI(-)-MS. This work illustrates the potential of ambient mass spectrometry for the direct monitoring of polymerization reactions on surfaces.
authors.affiliation: ThoMSon Mass Spectrometry Laboratory, Institute of Chemistry, University of Campinas-UNICAMP Campinas, SP, Brazil. awn@nrcwe.dk
authors.forename: Asger W
authors.initials: AW
authors.lastname: Nørgaard
authors.forename: Boniek G
authors.initials: BG
authors.lastname: Vaz
authors.forename: Frants R
authors.initials: FR
authors.lastname: Lauritsen
authors.forename: Marcos N
authors.initials: MN
authors.lastname: Eberlin
mesh_terms: D015394:Molecular Structure; D058105:Polymerization; D012821:Silanes / Q000737:chemistry*; D012833:Siloxanes / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
chemical_list: D012821:Silanes; D012833:Siloxanes