In this work, chitosan with an amorphous structure and high surface area (increased 30 times higher than that of initial chitosan) was obtained from the decrystallization of chitosan using a reprecipitation method of chitosan from solution. The chitosan was characterized using X-ray diffraction, Scanning Electron Microscopy (SEM) and Brunauer-Emmet-Teller (BET). | JOURNAL OF SCIENCE OF HNUE DOI Chemical and Biological Sci. 2015 Vol. 60 No. 9 pp. 21-26 This paper is available online at http PREPARATION AND INVESTIGATION OF ADSORPTION CAPACITY FOR METAL IONS OF AMORPHOUS CHITOSAN Do Truong Thien1 Nguyen Tien An2 Nguyen Thi Hoa2 and Pham Thanh Khiet2 1 Institute of Chemistry Vietnam Academy of Science and Technology 2 Thai Binh University of Medicine and Pharmacy Thai Binh Abstract. In this work chitosan with an amorphous structure and high surface area increased 30 times higher than that of initial chitosan was obtained from the decrystallization of chitosan using a reprecipitation method of chitosan from solution. The chitosan was characterized using X-ray diffraction Scanning Electron Microscopy SEM and Brunauer-Emmet-Teller BET . The adsorption capacity of the decrystallized chitosan for many metal ions has been evaluated. The results show that the adsorption capacity of decrystallized chitosan for the metal ions increased and the values obtained were to times higher than that of other results reported in experimental ranges. Keywords Chitosan decrystallization heavy metals adsorption. 1. Introduction Chitin is a naturally abundant biopolymer like cellulose that is present in the shell of crustaceans such as crab and shrimp the cuticle of insects and also the cell wall of some fungi and microorganisms. Chitin consists of 2-acetamido-2-deoxy- 1-4 - -D-glucopyranose residues N-acetyl-D-glucosamine units which has intra- and inter-molecular hydrogen bonds and is water-insoluble due to its rigid crystalline structure. Chitosan ideally consists of 2-amino-2-deoxy- 1-4 - -D-glucopyranose residues D-glucosamine units and has no or a small amount of N-acetyl-D-glucosamine units and is water-soluble as the salt with various acids on the amino group of D-glucosamine unit 1 . The possibility of extending the use of chitosan to immobilize biologically active species or to remove
