Deposition of a Chitosan Coating on Celgard Porous Matrices in the Presence of Carbon Dioxide under Pressure

It is shown that a chitosan coating can be deposited on the pore surface of Celgard polyolefin matrices from aqueous solutions of chitosan saturated with carbon dioxide under high pressure; i.e., when carbonic acid is formed. To ensure the stability of the coating, the initially hydrophobic matrices should be pretreated in the presence of peroxycarbonic acid, which is formed when the aqueous solution of hydrogen peroxide is saturated with carbon dioxide at a high pressure. The morphology of the deposited coating is studied by high-resolution microscopy. The introduced hydrophilic properties are evaluated from a change in the nature of the wetting of the matrix surface with water. It is found that the hydrophilized matrix modified with chitosan, in spite of a lower characteristic pore size, has ~1.5 times higher permeability for water than the initial matrix.