The effects of chitin/chitosan nanowhiskers on the thermal, mechanical and dye adsorption properties of electrospun PVA nanofibrous membranes

Poly(vinyl alcohol) (PVA) nanofibrous membranes (NFMs) containing various contents of alpha-chitin nanowhiskers (CtNWs) or chitosan nanowhiskers (CsNWs) were fabricated via electrospinning. The CtNWs were extracted by acid hydrolysis of chitin obtained from shrimp shells. The CsNWs were prepared by surface deacetylation of CtNWs by alkaline treatment. The CtNWs and CsNWs were characterized using transmission electron microscopy and X-ray diffractometry. The morphological and structural analyses of the PVA NFMs containing CtNWS or CsNWs were conducted by field emission scanning electron microscopy and attenuated total reflectance infrared spectroscopy. Also, the physical properties of the NFMs were investigated using thermogravimetric analysis and texture analyzer. The adsorption capacity toward cationic methylene blue of the PVA NFMs with CtNWs or CsNWs was evaluated using UV-Vis spectrophotometry, and it was found that the electrostatic repulsive force due to the surface positive charges of CtNWs and CsNWs reduced the adsorption performance.