A novel method for the preparation of silver/chitosan--methoxy polyethylene glycol core shell nanoparticles

Uniformly sized silver/chitosan--methoxy polyethylene glycol (chitosan--MPEG) core shell nanoparticles with different degree of substitution were synthesized. Thus, -phthaloyl chitosan is reacted with polyethylene glycol monomethyl ether iodide in the presence of silver oxide by the following steps. At first, amino groups of chitosan are protected by fourfold excess of phthalic anhydride. Then -phthaloyl chitosan is reacted with an appropriate amount of monomethyl ether iodide in the presence of silver oxide and lastly -phthaloyl groups are removed to yield silver/chitosan--MPEG core shell nanoparticles. Structure of prepared silver/chitosan--MPEG core shell nanoparticles have been characterized by UV/Vis spectroscopy, transmission electron microscopy (TEM), Fourier transform infrared (FT-IR), X-ray diffraction, and scan electron microscopy (SEM-EDX). Experimental results revealed that the prepared silver core particles had the size 18 +/- A 2 nm. Core shell structure with chitosan--MPEG-coating had the size 40 +/- A 2 nm.