Electrospun Micro/nanoifbrous Membrane Of Lignin/cellulose Acetate Blend For Heavy Metal Ions Adsorption

Micro/nanofibrous membrane of lignin/cellulose acetate blend was prepared byelectrospinning method and the adsorption metal ion on membrane was studied in thispaper. First, dissolved lignin and cellulose acetate in suitable solvent, lignin/cellulose acetatenano/microfibrous blend were obtained via electrospinning method. Effect of method ofpreparing electropinning solution, solvent and proportion of lignin/cellulose acetate on fiberdiameter and morphology were discussed. Scanning electron microscopy (SEM), tensiletesting machine, surface contact measurement instrument were characterized membranemorphology and properties. The results showed that only acetone–tetrahydrofuran (THF)(v: v=1:1) solvent systems enables continuous formation of fibers as for solution A;only acetic acid as solvent for lignin and acetone/tetrahydrofuran (v: v=1:1) solvent forcellulose acetate to get continuous smooth fiber as for solution B. The proportion of ligninand cellulose acetate not only affected the morphology and diameter of the fiber but alsoproperties of the fibers including mechanical, and the hydrophilic. Second, the fine structureof the lignin/cellulose acetate blend membrane was characterized by FTIR, Scanningelectron microscopy (SEM), Differential scanning calorimetry (DSC), Confocal laserscanning microscope (CLSM). The results showed that lignin and cellulose acetate werepartly incompatible in diameter as far as optical micrograms reveal. Lignin/cellulose blendshowed a cocontinuous nanofiber structure due to phase separation in the spinning.Finally, the adsorption capacity of lignin/cellulose acetate was researched. The nanofbercomposition, initial metal ion concentration, contact time and pH of the solution affected theadsorption capacity. The adsorption tests revealed that lignin-based nanofbers had affinitywith metal ions in the following order: Cu2+> Ag+. And the adsorption capacity increasedwith increasing temperature and initial metal ion concentration. The adsorption onto the blendfibers was highly pH-dependent, and the optimum pH was found4for Ag+and5for Cu2+.Composition of fibers had little effect on adsorption capacity. The experimental data ft thepseudo second-order kinetic model and the equilibrium data can ft well to the Langmuirisotherm.