Chitosan-polyethylene glycol coated cotton membranes for wound dressings

Membranes have been developed by coating a blend of chitosan (CS) and polyethylene glycol (PEG) of different molecular weights (4000, 10,000 and 20,000) on cotton fabric followed by freeze drying. The influence of PEG molecular weight on the physical characteristics of the membranes has been investigated. The scanning electron microscopy of the coated fabric reveals porous structure. The porosity of the material is found to be 51-70% and the pore size in the range of 75-120 microns. The increase in the PEG content in the blend composition causes destabilization of pores, leading to an increase in the pore size with elongated morphology. There seems to be phase separation between the two components, which is an important factor for the observed behaviour of the porous structure. The air and water permeability of the membranes tends to increase with the increase in PEG molecular weight. The PEG addition to membrane leads to the development of a more flexible matrix depending on the amount of PEG.