Chitosan (CS), a biomaterial obtained via alkaline N-deacetylation of chitin, has recently attracted much attention from scientists across the globe. After cellulose, it is the second highest naturally occurring polymer on earth. It shows many excellent biological properties such as nontoxicity, biodegradability, antimicrobial activity, and immunological activity. As a membrane material, it has got excellent lm-forming nature and hydrophilic in nature. Although the polymer backbone consists of hydrophilic functional groups, CS is normally insoluble in water and most of the common organic solvents. Chemical modication of CS is the best method to enhance its solubility at neutral pH or in organic solvents. So the obtained derivatives have got vast applications in the biomedical eld as well as membrane technology.