Preparation of the Electrospun Chitosan Nanofiber Mats and their Applications in the Adsorption of Cu(II) and Pb(II) from solution
Haider, S . 2009
The metal adsorbability of the chitosan electrospun nanofiber (∼235 nm in diameter) mats was examined in an aqueous solution. The chitosan nanofiber mats (which were neutralized with potassium carbonate) showed good erosion stability in water and high adsorption affinity for metal ions in an aqueous solution. The adsorption data of Cu(II) and Pb(II) (which were determined by a spectrophotometric method) were fitted well with Langmuir isotherm indicating that mono-layer adsorption occurred on the nanofiber mats. The equilibrium adsorption capacities (from Langmuir isotherm data) for Cu(II) and Pb(II) were 485.44 mg g−1(2.85 mmol g−1) and 263.15 mg g−1 (0.79 mmol g−1), respectively. The Cu(II) adsorption data were ∼6 and ∼11 times higher than the reported highest values of chitosan microsphere (80.71 mg g−1) [W.S. Wan Ngah, C.S. Endud, R. Mayanar, Removal of copper(II) ions from aqueous solution onto chitosan and cross-linked chitosan beads, React. Funct. Polym. 50 (2002) 181–190] and the plain chitosan (45.20 mg g−1) [C. Huang, Y.C. Chung, M.R. Liou, Adsorption of Cu(II) and Ni(II) by pelletized biopolymer, J. Hazard. Mater. 45 (1996) 265–277], respectively. This high adsorption capacity suggests that the chitosan electrospun nanofiber mats can be applied to filter out (or neutralize) toxic metal ions and microbes without losing their original chitosan properties such as biocompatibility, hydrophilicity, bioactivity, non-antigenicity, and non-toxicity.
We prepared multi-walled carbon nanotube (MWNT)/gelatin composites by dispersion of MWNT through ultrasonication in an aqueous medium with anionic surfactant sodium dodecyl sulfate (SDS).