pH responsive graft copolymers of chitosan.

Grafting suitable polymers onto chitosan can produce cationic or polyampholyte polymers or hydrogels that are potential smart biomedical materials. Chitosan-graft-[poly(diethylamino)ethyl methacrylate] has been prepared in three different physical forms as linear free chains in solution, chemical gels crosslinked with glutaraldehyde, and poly(diethylamino)ethyl methacrylate] grafted onto chitosan tripolyphosphate gel beads. In addition to chemical structure, the graft copolymers were characterized with respect to their dissolution and swelling behavior in aqueous solution.

Efficient removal of lead (II) ions and methylene blue from aqueous solution using chitosan/Fe-hydroxyapatite nanocomposite beads.

Chitosan is a well-known sorbent and effective in the uptake of anionic or reactive dyes, but it has deficiency in adsorption of basic dyes. In this work, chitosan/Fe-substituted hydroxyapatite composite beads were prepared in a different ratio via embedding of hydroxyapatite into chitosan solution for removal of basic dye and heavy metal from aqueous solution. The composite beads were characterized by Fourier transform infrared spectroscopy and scanning electron microscopy in order to reveal their composition and surface morphology.