Preparation and properties of highly soluble chitosan–l-glutamic acid aerogel derivative

The objective of this work is to improve the solubility of chitosan at neutral or basic pH using the supercritical carbon dioxide (sc.CO2). A novel water-soluble chitosan–l-glutamic acid (Cl-GA) aerogel derivative was synthesized by reaction of 85% deacetylated chitosan with l-glutamic acid (l-GA) in aq.AcOH subjected to solvent exchange prior to using sc.CO2 as a nonsolvent for the polymer. The prepared aerogel derivative and molecular conformation of modified chitosan are characterized by using UV, FTIR, 1H NMR, and CD techniques. Some physical properties and surface morphology were analyzed by X-ray diffraction, differential scanning calorimetry (DSC), thermogravimetry (TG), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and porosimetry analysis. Overall, the sc.CO2 assisted chitosan aerogel derivative opens new perspectives in biomedical applications.