Dioxide/Chitosan/poly(lactide-co-caprolactone) composite membrane with efficient Cu(II) adsorption

Abstract

Herein, titanium dioxide/chitosan/poly(lactide-co-caprolactone) (TiO2/CS/P(LLA-CL)) composite membranes with highly efficient adsorption of copper ions (Cu(II)) in aqueous solution were developed, through a facile electrospinning method. First, TiO2 nanoparticles were ultrasonically dispersed in CS/P(LLA-CL) solution to get a uniform suspension. Afterwards, the mixture was applied for electrospinning to generate the smooth and bead-free composite membranes. The high adsorption capability of the composite membranes on Cu(II) was mainly attributed to the combination of TiO2 nanoparticles, CS/P(LLA-CL) matrix and nanosized membrane. Among those, the TiO2/CS/P(LLA-CL) composite membrane with 2% TiO2 content demonstrated the maximum adsorption capability (˜190.5 mg g−1) for Cu(II) from aqueous solution. Their adsorption behaviors were well conformed to pseudo-second-order kinetic model and Langmuir isotherm model. Moreover, FTIR and XPS results confirmed the existed chelation and ion exchange between the membrane and the Cu(II) during adsorption process. Due to its simplicity, effectiveness and stability in water, this type of composite membrane may serve as a promising environmentally-friendly and non-toxic adsorbent for removal of Cu(II) in aqueous.