Surface functionalization of chitosan with 5-nitroisatin

Area of Science:

• Materials Science
• Computational Chemistry
• Polymer Chemistry

Background:

• Chitosan (CS) is a biocompatible polymer with diverse applications.
• 5-nitroisatin (NI) is a molecule with potential biological activity.
• Surface functionalization of polymers like CS can enhance their properties.

Purpose of the Study:

• To investigate the surface adsorption of 5-nitroisatin on chitosan.
• To explore both noncovalent and covalent functionalization mechanisms.
• To synthesize and characterize a novel chitosan-NI Schiff base and its metal complexes.

Main Methods:

• Quantum mechanical calculations (DFT) for adsorption and electronic properties.
• AIM analysis for hydrogen bonding interactions.
• Synthesis and characterization of Schiff base and metal complexes (Elemental Analysis, IR, TGA, DSC).

Main Results:

• Identified energetically stable configurations for NI adsorption on CS.
• Demonstrated increased solubility of NI and CS in each other's presence.
• Confirmed the possibility of covalent functionalization via Schiff base formation.
• Successfully synthesized and characterized the chitosan Schiff base (CSB) and its Ni(II) and Cu(II) complexes.

Conclusions:

• The study provides a theoretical and experimental basis for chitosan functionalization with 5-nitroisatin.
• The synthesized Schiff base and its metal complexes show promise for various applications.
• Computational methods accurately predicted experimental observations.