Polyhydroxybutyrate–calcium alginate/carboxyl multi-walled carbon nanotubes composite nanofibrous
filtration membranes (PHB–CaAlg/CMWCNT) were prepared by electrospinning technique combined
with redissolving the top hydrogel nanofibrous layer to form dense thin film as barrier layer on PHB
nanofibrous substrate through suitable water mist wetting process and Ca
2+
cross-linking. The obtained
PHB/CaAlg nanofibrous membrane by synchronization electrospinning could improve the hydrophilic
property as middle layer and closely integrate with the top hydrogel layer. The morphology of the mem-
branes was observed by SEM. The hydrophilic property, tensile mechanical property, dye adsorption and
filtration properties were characterized. The results showed that the tensile mechanical property and
hydrophilic property of PHB–CaAlg/CMWCNT membrane were significantly improved, and the dye
Brilliant blue adsorption capacity was twice higher than PHB–CaAlg membrane. The flux and rejection
rate of PHB–CaAlg/CMWCNT membrane for Brilliant blue were 32.95 L/m
2
h and 98.20%, respectively.
The thickness of PHB–CaAlg/CMWCNT membrane was about 40–50
l
m and the membrane consisted
of 20
l
m PHB nanofibrous substrate, 10
l
m PHB/CaAlg membrane and 10–20
l
m CaAlg/CMWCNT mem-
brane. The optimum time of water mist wetting process and Ca
2+
cross-linking was 5 min and 8 h, respec-
tively. This PHB–CaAlg/CMWCNT membrane has promising applications as nano-filtration membrane
with high flux and rejection rate for small organic molecules in wastewater under low operating pressure