Effect of crosslinking on the solubility and morphological structures of the PVA nanofibres

The electrospun PVA nanofibres are highly soluble in water. Hence, an improvement to stabilize the nanofibres in water has been investigated in the study. The PVA nanofibres were crosslinked with Hexamethylene diisocyanate(HMDI), N, N-Dimethylformamide(DMF) and a mixture of HMDI and DMF. The structures and properties of crosslinked electrospun PVA nanofibres were characterized using the SEM and FTIR. Changes of the membrane area, thickness and membrane stability in water were also investigated. The results show that the PVA nanofibres insoluble in water after crosslinking. The presence of N-H and C=O groups give stable nanofibres in water. However, the structures of nanofibres vary depending upon chemicals used. The HMDI gives similar fibre structures to the uncrosslinked PVA nanofibres. However, the DMF and a mixture of HMDI and DMF change the PVA nanofibre structures. The HMDI is also found to form crosslinking network between the PVA fibres that could improve the fibre-to-fibre bonding in the PVA membrane. From the results, it shows that the HMDI is not only improved the solubility of PVA nanofibres, but it can be used as binding agent for random-oriented fibres.