In
this study, a polyamide forward osmosis membrane was functionalized
with zwitterions followed by the in situ growth of metal–organic
frameworks with silver as a metal core (Ag-MOFs) to improve its antibacterial
and antifouling activity. First, 3-bromopropionic acid was grafted
onto the membrane surface after its activation with
N
,
N
-diethylethylenediamine. Then, the in situ growth
of Ag-MOFs was achieved by a simple membrane immersion sequentially
in a silver nitrate solution and in a ligand solution (2-methylimidazole),
exploiting the underlying zwitterions as binding sites for the metal.
The successful membrane functionalization and the enhanced surface
wettability were verified through an array of characterization techniques.
When evaluated in forward osmosis tests, the modified membranes exhibited
high performance and improved permeability compared to pristine membranes.
Static antibacterial experiments, evaluated by confocal microscopy
and colony-forming unit plate count, resulted in a 77% increase in
the bacterial inhibition rate due to the activity of the Ag-MOFs.
Microscopy micrographs of the
Escherichia coli
bacteria suggested the deterioration of the biological cells. The
antifouling properties of the functionalized membranes translated
into a significantly lower flux decline in forward osmosis filtrations.
These modified surfaces displayed negligible depletion of silver ions
over 30 days, confirming the stable immobilization of Ag-MOFs on their
surface.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.