Synthesis and characterisation of novel Halloysite Nanotubes/chitosan composite membranes

Novel membranes of chitosan/Halloysite Nanotubes (HNTs) nanocomposites were prepared using solution casting method by adding 2 wt%, 5 wt%, 10 wt% and 15 wt% of HNTs. Mechanical properties, such as Young's modulus and tensile strength of nanocomposites at 5w% of HNTs significantly improved by 21% and 34%, respectively, compared to unreinforced chitosan membranes. At high HNT concentrations mechanical properties were slightly inferior to the chitosan membranes with 5 wt% of HNTs, due to the aggregation of HNTs. Scanning electron microscopy (SEM) of membranes at 2 % and 5 wt% of HNTs showed low amounts of pulled-out nanotubes which confirmed the presence of more embedded nanotubes inside the chitosan matrix as well as less amounts of micro-voids at the fractured surface of chitosan/HNTs nanocomposites. FTIR shows possible interaction of external surface siloxane groups of the HNTs with the matrix. Thermal Gravimetric Analysis (TGA) revealed that thermal stability of nanocomposites increased by increasing the HNTs concentrations.