Preparation and adsorption of novel cellulosic fibers modified by β-cyclodextrin

Novel cellulosic fibers modified by beta-cyclodextrin (CFEC) were prepared for adsorption for heavy metal ions like copper (II) and organic dye like neutral red from their aqueous solutions. The modified cellulosic fibers gave higher copper ion adsorption, and showed copper ion uptake values of 6.24 mg/g at 293 degrees C, as against no adsorption for unmodified cellulosic fibers. Adsorption isotherm model indicated the adsorption of the novel modified fibers for heavy metal ions best fitted for Langmiur model. The adsorption was an exothermic reaction, and the reaction caloric was 6.295 kJ/ mol. Copper ions could form a 7:4 complex with beta-cyclodextrin (beta-CD). The novel modified cellulosic fibers could also form inclusion complexes with neutral red via beta-CD molecules. In addition, it was found that the novel modified cellulosic fibers had nearly the same mechanical and thermal properties as the unmodified cellulosic fibers because the modification did not destroy the main chain of cellulose molecules. Copyright (C) 2008 John Wiley & Sons, Ltd.