| Summary: | The objective of this study was to develop and characterize the
polyethersulfone (PES) incorporated with silver (Ag) as an antibacterial membrane
which can remove and disinfect bacteria in a single step for environmental
application. The PES-Ag membrane was developed from PES, silver nitrate as an
antibacterial agent and 2,4,6-triaminopyrimidine (TAP) as compatibilizer. The
influence of AgNO3 loading, molecular weights (MW) of polyvinylpyrrolidone
(PVP) as dispersant and type of compatibilizer have been investigated. The resulting
membranes were characterized based on their thermal, tensile and structural
properties which were used in correlation with the membrane antibacterial properties.
The incorporation of Ag in PES membrane has increased the tensile strength doubled
as compared to the unmodified PES. Furthermore, it was observed that the highest
AgNO3 loading (2 wt%) and the highest MW (360,000) of PVP as dispersant has led
to higher silver content on membrane surfaces. This is evidenced from energy
dispersive X-ray (EDX) analysis and X-ray photoelectron spectroscopy (XPS). These
properties have induced a better antibacterial activity in a disc-diffusion test against
Escherichia coli (E.coli) and Staphylococcus aureus (S.aureus). The structural
characterization by field emission scanning electron microscope (FESEM) revealed
that by incorporating TAP as compatibilizer, smaller Ag particles size with improved
distribution and average pore size of 0.174 µm was obtained. In addition, the silver
residue during fabrication monitored by inductive coupled plasma-mass spectrometry
(ICP-MS) was significantly reduced (62.6%). These parameters have led to E.coli
removal of log reduction value (LRV) 3.59 and 100% growth inhibition tested on
E.coli suspension of 1×106
colony forming unit (CFU/mL). From the adhesion test,
this membrane exhibited the least E.coli adherence which in turn evidenced its anti�adhesion property. In conclusion, the PES-Ag membrane with TAP as compatibilizer
produced was potential in bacteria removal and disinfection below the CFU
maximum range for water and waste water treatment.
|
|---|