Controlling Polymerization Initiator Concentration
in Mesoporous Silica Thin Films
Fabio Krohm
Haiko Didzoleit
Marcus Schulze
Christian Dietz
Robert
W. Stark
Christian Hess
Bernd Stühn
Annette Brunsen
10.1021/la404004f.s001
https://acs.figshare.com/articles/journal_contribution/Controlling_Polymerization_Initiator_Concentration_in_Mesoporous_Silica_Thin_Films/2332948
We
present a strategy toward controlled polymer density in mesopores
by specifically adjusting the local amount of polymerization initiator
at the pore wall. The polymerization initiator concentration as well
as the polymer functionalization has a direct impact on mesoporous
membrane properties such as ionic permselectivity. Mesoporous silica-based
thin films were prepared with specifically adjusted amount of polymerization
initiator (4-(3-triethoxysilyl)propoxybenzophenone (BPSilane)) or
initiator binding functions ((3-aminopropyl)triethoxysilane (APTES)),
directly and homogeneously incorporated into the silica wall pursuing
a sol–gel-based co-condensation approach. The amount of polymerization
initiator was adjusted by varying its concentration in the sol–gel
precursor solution. The surface chemistry, porosity, pore accessibility,
and reactivity of the surface functional groups were investigated
by using infrared spectroscopy, X-ray photoelectron spectroscopy,
X-ray reflectometry, ellipsometry, atomic force microscopy, and transmission
electron microscopy. We could gradually modify the amount of reactive
polymerization initiators in these mesoporous membranes. Mesopores
were maintained for APTES containing films for all tested ratios up
to 25 mol % and for BPSilane containing films up to 15 mol %. These
films showed accessible and charge-dependent ionic permselectivity
and an increasing degree of functionalization with increasing precursor
ratio. This approach can directly result in control of polymer grafting
density in mesoporous films and thus has a direct impact on applications
such as the control of ionic transport through mesoporous silica membranes.
2014-01-14 00:00:00
reactive polymerization initiators
Controlling Polymerization Initiator Concentration
polymerization initiator concentration
APTES
mesoporous membrane properties
polymerization initiator
mesoporous silica membranes
transmission electron microscopy
film