An increasing interest has recently been shown to use chitin/chitosan oligomers (chito-oligomers) in medicine and food fields because they are not only water-soluble, nontoxic, and biocompatible materials, but they also exhibit numerous biological properties, including antibacterial, antifungal, and antitumor activities, as well as immuno-enhancing effects on animals. Conventional depolymerization methods of chitosan to chito-oligomers are either chemical by acid-hydrolysis under harsh conditions or by enzymatic degradation. In this work, hydrolysis of chitosan to chito-oligomers has been achieved by applying adsorption-separation technique using diluted HCl in the presence of different types of zeolite as adsorbents. The chito-oligomers were retrieved from adsorbents and characterized by differential scanning calorimetry (DSC), liquid chromatography/mass spectroscopy (LC/MS), and ninhydrin test.

First- and second-generation hydroxyl- terminated dendrimers were prepared starting from a 1,3-diaminopropane core and sulfonimide linkers. A first-generation mesitylene-derived dendrimer was also prepared with the same terminals. The dendrimers were then reacted with Fe3+, Al3+, and UO22+ separately in order to apply the dendrimers for binding these metals, which have important industrial applications and pose environmental problems simultaneously. The prepared dendrimers were also shown to bind Fe3+ selectively from mixtures with Al3+.