Nano-hydroxyapatite incorporated gelatin/zein nanofibrous membranes: Fabrication, characterization and copper adsorption

In this study, the gelatin/zein nanofibrous membranes with incorporation of nano-hydroxyapatite (nHA) were fabricated via electrospinning. The gelatin/zein/nHA solutions as the spinning dispersions showed the viscoelastic property with a shear-thinning non-Newtown behavior. The incorporated nHA particles in the composite nanofibrous membranes did not affect the average fiber diameter significantly, but induced agglomeration and nodules at higher contents. It was found that nHA was dispersed within the gelatin/zein nanofibers by the formed hydrogen bonding, resulting in a more extensional structure of the proteins. The addition of nHA significantly increased the hydrophobicity of the nanofibrous membranes, due to the lower ratio of polar groups exposed outside. However, the incorporation of nHA improved the mechanical property at a low content of 10%, but resulted in a more brittle and fragile property at higher contents. The copper adsorption capacity of the gelatin/zein nanofibrous membrane increased from 27.2 to 67.8 mg/g after the addition of up to 50% nHA. This work suggests the potentials of the electrospun gelatin/zein/nHA nanofibrous membranes as desirable materials for metal removal applications. (C) 2019 Elsevier B.V. All rights reserved.