Porous Melamine-Formaldehyde Monoliths by Step-Growth Polymerization Reactions via an Organic Sol-gel Process
(English)In: Microporous and Mesoporous Materials, ISSN 1387-1811Article in journal (Refereed) Submitted
In this explorative study, twenty hydrophilic melamine-formaldehyde (MF) monolith materials were synthesized by acid-catalyzed polycondensation of systems consisting of an aqueous MF precondensate, a block copolymeric surfactant as main porogen, and short aliphatic polyethers as co-porogens, which were dispersed in three different organic solvents covering a wide span in polarity. The molecular size and type of aliphatic polyether (co-porogen), and of the ratio of solvents to the other components were investigated by an experimental design that resulted in monolithic materials covering a wide range of different meso- and macroporous properties. A multivariate assessment revealed that the strongest contributors to the mesopore size and the inversely related surface area were the co-porogens, whereas the macropore dimension was explained by the solvents and the ratio between solvents and the other components. Surface elemental analysis by XPS showed slight differences in the bridging type between monoliths of opaque glass-like vs. white solid appearance. Measurements ζ-potentials in 10 mM ammonium acetate showed that the MF monoliths had no net charge at neutral pH, and +11 and –13 mV at pH 4 and 9.5, respectively.
Research subject Analytical Chemistry
IdentifiersURN: urn:nbn:se:umu:diva-89309OAI: oai:DiVA.org:umu-89309DiVA: diva2:719786
FunderSwedish Research Council, 2012-4000