title: Visualization and characterization of interfacial polymerization layer formation.
abstract: We present a microfluidic platform to visualize the formation of free-standing films by interfacial polymerization. A microfluidic device is fabricated, with an array of micropillars to stabilize an aqueous-organic interface that allows a direct observation of the films formation process via optical microscopy. Three different amines are selected to react with trimesoyl chloride: piperazine, JEFFAMINE(®)D-230, and an ammonium functionalized polyhedral oligomeric silsesquioxane. Tracking the formation of the free-standing films in time reveals strong effects of the characteristics of the amine precursor on the morphological evolution of the films. Piperazine exhibits a rapid reaction with trimesoyl chloride, forming a film up to 20 μm thick within half a minute. JEFFAMINE(®)D-230 displays much slower film formation kinetics. The location of the polymerization reaction was initially in the aqueous phase and then shifted into the organic phase. Our in situ real-time observations provide information on the kinetics and the changing location of the polymerization. This provides insights with important implications for fine-tuning of interfacial polymerizations for various applications.
authors.affiliation: Soft Matter, Fluidics and Interfaces, MESA+ Institute for Nanotechnology, Faculty of Science and Technology, University of Twente, Enschede, The Netherlands. r.g.h.lammertink@utwente.nl.
authors.forename: Yali
authors.initials: Y
authors.lastname: Zhang
authors.forename: Nieck E
authors.initials: NE
authors.lastname: Benes
authors.forename: Rob G H
authors.initials: RG
authors.lastname: Lammertink